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1.
Infection ; 43(3): 287-95, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25575463

RESUMEN

OBJECTIVE: To identify factors associated with short-term, intermediate and long-term outcome in patients with infective endocarditis (IE) and the need for treatment on intensive care unit (ICU). DESIGN AND SETTING: Retrospective analysis and long-term follow-up by questionnaire in the two medical ICUs of our university hospital. PATIENTS: We conducted a retrospective analysis of all consecutive patients with IE and need for ICU treatment in our department between 2002 and 2009. All patients fulfilled the modified Duke criteria for definite diagnosis of IE. MEASUREMENTS AND MAIN RESULTS: Data of 216 patients (aged 62 ± 14 years, 31 % female) were analyzed, 15.7 % of whom had prosthetic valve endocarditis. Infectious agent (IA) was identified in 74 % and surgery was performed in 57 %. 56 patients (24.9 %) died on ICU, 9 patients were sent to palliative care units and died several days later. During follow-up, another 44 patients died. Multivariate Cox-regression analysis identified the following independent risk factors: High initial SAPS II for 30d-, multiple organ failure and high maximum SAPS II for 100d- and high maximum leukocyte count for long-term mortality. Surgical intervention during ICU was an independent predictor of a better 30d outcome. CONCLUSIONS: In contrast to general IE populations, IA and the type of infected impaired valve are not main predictors of survival in critically ill IE-patients. Biomarker of acute infection and markers for severity of illness (scores and organ failure) are independent risk factors for mortality. The surgical clearance of infected valve, device or abscesses is an independent predictor of 30d outcome.


Asunto(s)
Endocarditis/epidemiología , Unidades de Cuidados Intensivos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Endocarditis/mortalidad , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Encuestas y Cuestionarios , Análisis de Supervivencia , Resultado del Tratamiento , Adulto Joven
2.
Curr Opin Cell Biol ; 9(3): 412-9, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9159081

RESUMEN

The defining feature of eukaryotic organisms is the cell nucleus. All nuclear proteins are synthesized in the cytoplasm and need to be imported through the nuclear pore complexes (NPCs) into the nucleus. Import can be directed by various signals, of which the classical nuclear localization signal (NLS) and the M9 import signal are the best characterized. The past year has provided insight into the functions of the key players in NLS- and M9-dependent import, the interactions of these key players and possible implications of these interactions for the import mechanism. Although an understanding of some of the steps in the import process is emerging, the molecular mechanism of the actual translocation through the NPC is still obscure.


Asunto(s)
Membrana Nuclear/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Nucleares/fisiología , Animales , Transporte Biológico , Compartimento Celular , Proteínas de Unión al GTP/fisiología , Humanos , alfa Carioferinas , beta Carioferinas , Proteína de Unión al GTP ran
3.
J Cell Biol ; 126(4): 925-34, 1994 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8051212

RESUMEN

The cotranslational translocation of proteins across the ER membrane involves the tight binding of translating ribosomes to the membrane, presumably to ribosome receptors. The identity of the latter has been controversial. One putative receptor candidate is Sec61 alpha, a multi-spanning membrane protein that is associated with two additional membrane proteins (Sec61 beta and gamma) to form the Sec61p-complex. Other receptors of 34 and 180 kD have also been proposed on the basis of their ability to bind at low salt concentration ribosomes lacking nascent chains. We now show that the Sec61p-complex has also binding activity but that, at low salt conditions, it accounts for only one third of the total binding sites in proteoliposomes reconstituted from a detergent extract of ER membranes. Under these conditions, the assay has also limited specificity with respect to ribosomes. However, if the ribosome-binding assay is performed at physiological salt concentration, most of the unspecific binding is lost; the Sec61p-complex then accounts for the majority of specific ribosome-binding sites in reconstituted ER membranes. To study the membrane interaction of ribosomes participating in protein translocation, native rough microsomes were treated with proteases. The amount of membrane-bound ribosomes is only slightly reduced by protease treatment, consistent with the protease-resistance of Sec61 alpha which is shielded by these ribosomes. In contrast, p34 and p180 can be readily degraded, indicating that they are not essential for the membrane anchoring of ribosomes in protease-treated microsomes. These data provide further evidence that the Sec61p-complex is responsible for the membrane-anchoring of ribosomes during translocation and make it unlikely that p34 or p180 are essential for this process.


Asunto(s)
Retículo Endoplásmico/metabolismo , Fusión de Membrana , Proteínas de la Membrana/metabolismo , Microsomas/metabolismo , Páncreas/metabolismo , Prolactina/biosíntesis , Prolactina/metabolismo , Precursores de Proteínas/metabolismo , Ribosomas/metabolismo , Animales , ADN/metabolismo , Perros , Retículo Endoplásmico/ultraestructura , Cinética , Liposomas/metabolismo , Microsomas/ultraestructura , Páncreas/ultraestructura , Biosíntesis de Proteínas , Precursores de Proteínas/biosíntesis , Procesamiento Proteico-Postraduccional , Proteolípidos/aislamiento & purificación , Proteolípidos/metabolismo , ARN Mensajero/metabolismo , Ribosomas/ultraestructura , Canales de Translocación SEC , Transcripción Genética
4.
J Cell Biol ; 113(1): 35-44, 1991 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-1848866

RESUMEN

Using a photocross-linking approach we have investigated the cytosolic and membrane components involved in the targeting and insertion of signal-anchor proteins into the membrane of the ER. The nascent chains of both type I and type II signal-anchor proteins can be cross-linked to the 54-kD subunit of the signal recognition particle. Upon addition of rough microsomes the type I and type II signal-anchor proteins interact with a number of components. Both types of protein interact with an integral membrane protein, the signal sequence receptor, previously identified by its proximity to preprolactin during its translocation (Wiedmann, M., T.V. Kurzchalia, E. Hartmann, and T.A. Rapoport. 1987. Nature [Lond.] 328:830-833). Three proteins, previously unidentified, were found to be cross-linked to the nascent chains of the signal-anchor proteins. Among them was a 37-kD protein that was found to be the main component interacting with the type I SA protein used. These proteins were not seen in the absence of membranes suggesting they are components of the ER. The ability of the nascent chains to be cross-linked to these identified proteins was shown to be abolished by prior treatment with agents known to disrupt translocation intermediates or ribosomes. We propose that the newly identified proteins function either in the membrane insertion of only a subset of proteins or only at a specific stage of insertion.


Asunto(s)
Retículo Endoplásmico/metabolismo , Proteínas de la Membrana/metabolismo , Señales de Clasificación de Proteína/fisiología , Ribonucleoproteínas/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Transporte Biológico , Compartimento Celular , Reactivos de Enlaces Cruzados , Técnicas In Vitro , Membranas Intracelulares/metabolismo , Proteínas de la Membrana/química , Datos de Secuencia Molecular , Peso Molecular , Precursores de Proteínas/metabolismo , Receptores de Superficie Celular/química , Receptores de Superficie Celular/metabolismo , Proteínas Recombinantes/metabolismo , Ribosomas/metabolismo , Partícula de Reconocimiento de Señal , Tripsina/farmacología
5.
J Cell Biol ; 138(1): 65-80, 1997 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-9214382

RESUMEN

The importin-alpha/beta complex and the GTPase Ran mediate nuclear import of proteins with a classical nuclear localization signal. Although Ran has been implicated also in a variety of other processes, such as cell cycle progression, a direct function of Ran has so far only been demonstrated for importin-mediated nuclear import. We have now identified an entire class of approximately 20 potential Ran targets that share a sequence motif related to the Ran-binding site of importin-beta. We have confirmed specific RanGTP binding for some of them, namely for two novel factors, RanBP7 and RanBP8, for CAS, Pse1p, and Msn5p, and for the cell cycle regulator Cse1p from Saccharomyces cerevisiae. We have studied RanBP7 in more detail. Similar to importin-beta, it prevents the activation of Ran's GTPase by RanGAP1 and inhibits nucleotide exchange on RanGTP. RanBP7 binds directly to nuclear pore complexes where it competes for binding sites with importin-beta, transportin, and apparently also with the mediators of mRNA and U snRNA export. Furthermore, we provide evidence for a Ran-dependent transport cycle of RanBP7 and demonstrate that RanBP7 can cross the nuclear envelope rapidly and in both directions. On the basis of these results, we propose that RanBP7 might represent a nuclear transport factor that carries an as yet unknown cargo, which could apply as well for this entire class of related RanGTP-binding proteins.


Asunto(s)
GTP Fosfohidrolasas/metabolismo , Proteínas de Unión al GTP/genética , Proteínas Nucleares/genética , Proteína de Unión al GTP ran , Secuencia de Aminoácidos , Animales , Sitios de Unión , Transporte Biológico , Núcleo Celular/metabolismo , Secuencia Conservada , Citoplasma/metabolismo , ADN Complementario , Proteínas de Unión al GTP/metabolismo , Guanosina Trifosfato/metabolismo , Células HeLa , Humanos , Carioferinas , Datos de Secuencia Molecular , Membrana Nuclear/metabolismo , Señales de Localización Nuclear , Proteínas Nucleares/metabolismo , Proteínas/metabolismo , Conejos , Receptores Citoplasmáticos y Nucleares , Homología de Secuencia de Aminoácido , Xenopus , beta Carioferinas
6.
J Cell Biol ; 121(4): 743-50, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-8491769

RESUMEN

We have identified membrane components which are adjacent to type I and type II signal-anchor proteins during their insertion into the membrane of the ER. Using two different cross-linking approaches a 37-38-kD nonglycosylated protein, previously identified as P37 (High, S., D. Görlich, M. Wiedmann, T. A. Rapoport, and B. Dobberstein. 1991. J. Cell Biol. 113:35-44), was found adjacent to all the membrane inserted nascent chains used in this study. On the basis of immunoprecipitation, this ER protein was shown to be identical to the recently identified mammalian Sec61 protein. Thus, Sec61p is the principal cross-linking partner of both type I and type II signal-anchor proteins during their membrane insertion (this work), and of secretory proteins during their translocation (Görlich, D., S. Prehn, E. Hartmann, K.-U. Kalies, and T. A. Rapoport. 1992. Cell. 71:489-503). We propose that membrane proteins of both orientations, and secretory proteins employ the same ER translocation sites, and that Sec61p is a core component of these sites.


Asunto(s)
Retículo Endoplásmico/metabolismo , Glicosilfosfatidilinositoles/metabolismo , Proteínas de la Membrana/metabolismo , Secuencia de Bases , Transporte Biológico , ADN , Membranas Intracelulares/metabolismo , Datos de Secuencia Molecular , Pruebas de Precipitina , Canales de Translocación SEC
7.
J Cell Biol ; 145(2): 255-64, 1999 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-10209022

RESUMEN

Importin beta is a major mediator of import into the cell nucleus. Importin beta binds cargo molecules either directly or via two types of adapter molecules, importin alpha, for import of proteins with a classical nuclear localization signal (NLS), or snurportin 1, for import of m3G-capped U snRNPs. Both adapters have an NH2-terminal importin beta-binding domain for binding to, and import by, importin beta, and both need to be returned to the cytoplasm after having delivered their cargoes to the nucleus. We have shown previously that CAS mediates export of importin alpha. Here we show that snurportin 1 is exported by CRM1, the receptor for leucine-rich nuclear export signals (NESs). However, the interaction of CRM1 with snurportin 1 differs from that with previously characterized NESs. First, CRM1 binds snurportin 1 50-fold stronger than the Rev protein and 5,000-fold stronger than the minimum Rev activation domain. Second, snurportin 1 interacts with CRM1 not through a short peptide but rather via a large domain that allows regulation of affinity. Strikingly, snurportin 1 has a low affinity for CRM1 when bound to its m3G-capped import substrate, and a high affinity when substrate-free. This mechanism appears crucial for productive import cycles as it can ensure that CRM1 only exports snurportin 1 that has already released its import substrate in the nucleus.


Asunto(s)
Proteínas Portadoras/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Ribonucleoproteínas Nucleares Pequeñas/metabolismo , Factores de Transcripción/metabolismo , Animales , Sitios de Unión , Núcleo Celular/metabolismo , Cromatografía de Afinidad , Citoplasma/metabolismo , Escherichia coli , Femenino , Células HeLa , Humanos , Carioferinas , Cinética , Modelos Biológicos , Proteínas Nucleares/aislamiento & purificación , Proteínas Nucleares/metabolismo , Oocitos/fisiología , Proteínas de Unión a Caperuzas de ARN , Receptores Citoplasmáticos y Nucleares/aislamiento & purificación , Proteínas Recombinantes/aislamiento & purificación , Proteínas Recombinantes/metabolismo , Transducción de Señal , Xenopus laevis , Proteína Exportina 1
8.
J Cell Biol ; 111(6 Pt 1): 2283-94, 1990 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-2177473

RESUMEN

Bifunctional cross-linking reagents were used to probe the protein environment in the ER membrane of the signal sequence receptor (SSR), a 24-kD integral membrane glycoprotein (Wiedmann, M., T. V. Kurzchalia, E. Hartmann, and T. A. Rapoport. 1987. Nature [Lond.]. 328:830-833). The proximity of several polypeptides was demonstrated. A 22-kD glycoprotein was identified tightly bound to the 34-kD SSR even after membrane solubilization. The 34-kD polypeptide, now termed alpha SSR, and the 22-kD polypeptide, the beta SSR, represent a heterodimer. We report on the sequence of the beta SSR, its membrane topology, and on the mechanism of its integration into the membrane. Cross-linking also produced dimers of the alpha-subunit of the SSR indicating that oligomers of the SSR exist in the ER membrane. Various bifunctional cross-linking reagents were used to study the relation to ER membrane proteins of nascent chains of preprolactin and beta-lactamase at different stages of their translocation through the membrane. The predominant cross-linked products obtained in high yields contained the alpha SSR, indicating in conjunction with previous results that it is a major membrane protein in the neighborhood of translocating nascent chains of secretory proteins. The results support the existence of a translocon, a translocation complex involving the SSR, which constitutes the specific site of protein translocation across the ER membrane.


Asunto(s)
Proteínas de Unión al Calcio , Reactivos de Enlaces Cruzados/farmacología , Retículo Endoplásmico/metabolismo , Glicoproteínas de Membrana/genética , Microsomas/metabolismo , Receptores de Superficie Celular/genética , Receptores Citoplasmáticos y Nucleares , Receptores de Péptidos , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Cromatografía de Afinidad , Clonación Molecular , ADN/genética , Perros , Membranas Intracelulares/metabolismo , Sustancias Macromoleculares , Glicoproteínas de Membrana/aislamiento & purificación , Glicoproteínas de Membrana/metabolismo , Modelos Estructurales , Datos de Secuencia Molecular , Peso Molecular , Fragmentos de Péptidos/aislamiento & purificación , Plásmidos , Biosíntesis de Proteínas , Conformación Proteica , Procesamiento Proteico-Postraduccional , ARN Mensajero/genética , Receptores de Superficie Celular/aislamiento & purificación , Receptores de Superficie Celular/metabolismo , Transcripción Genética , beta-Lactamasas/genética
9.
Science ; 271(5255): 1513-8, 1996 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-8599106

RESUMEN

Active transport of proteins and RNAs between the nucleus and cytoplasm is a major process in eukaryotic cells. Recently, factors that recognize transport substrates and mediate nuclear import or export have been characterized, revealing interactions that target substrates to the nuclear pore complexes, through which translocation occurs. Translocation requires energy, and for the import process this energy is at least partly consumed by the action of the small guanosine triphosphatase Ran. In the first half of the review, some of the well-established general background information on nucleocytoplasmic transport is discussed. The second half describes recent information on the mechanistic details of nuclear import and export as well as major unresolved issues such as how directionality is conferred on either import or export. The whole review is slanted toward discussion of metazoan cells.


Asunto(s)
Núcleo Celular/metabolismo , Citoplasma/metabolismo , Proteínas/metabolismo , ARN/metabolismo , Secuencia de Aminoácidos , Animales , Transporte Biológico Activo , Proteínas de Unión al GTP/metabolismo , Humanos , Carioferinas , Datos de Secuencia Molecular , Proteínas Nucleares/metabolismo , Señales de Clasificación de Proteína/metabolismo , Proteínas de Unión a Caperuzas de ARN , Proteínas de Unión al ARN/metabolismo , Proteína de Unión al GTP ran
10.
Clin Respir J ; 12(3): 1106-1117, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-28398662

RESUMEN

OBJECTIVES: The influence of blood group antigens on cancerogenesis is shown for distinct tumor types, yet the impact of Rhesus blood group antigens in lung cancer is not clarified. MATERIALS AND METHODS: To investigate the impact of Rhesus blood groups a non-small cell lung cancer (NSCLC) collective (n = 1047) was analyzed retrospectively. Using a second cohort of n = 340 primarily operated stage I-III NSCLC patients, we evaluated immunohistochemistry of CD47-antibody stained tissue samples in correlation to histopathologic subtype and Rhesus blood group. RESULTS AND CONCLUSION: In 516 of 1047 patients blood group data were available. Seven different RhCE phenotypes were grouped as "··ee," "ccE·," and "C·E·." Adenocarcinoma patients with Rh "··ee" revealed improved overall survival (29 (21.2-36.8) m; HR 1.00 [index]) compared with Rh "ccE·" (19 (1.9-36.1) m; HR 1.76 [1.15-2.70]) and Rh "C·E·" (10 (7.4-12.6) m; HR 2.65 [1.70-4.12]) univariately (P < .001) and multivariately (P < .001). Rh "··ee" showed reduced incidence of CNS-metastasis (P = .014) and metastasis count (P = .032) in stage IV adenocarcinoma. Immunohistochemistry associated CD47-positivity with adenocarcinomas (n = 340, P = .048). In n = 51 cases blood group data were available. The prognostic effect of Rh "··ee" compared with Rh "ccE·" and Rh "C·E·" was stated (P = .001), foremost in CD47-positive adenocarcinomas (Rh "··ee" vs. Rh "ccE·" and Rh "C·E·," P = .008). Inversely Rh "ccE·" or Rh "C·E·" was found beneficial in CD47-negative non-adenocarcinomas (P = .046). Phenotypic RhCE expression may be an independent prognostic factor for overall survival in adeno-NSCLC. We hypothesize an erythrocytic-immunologic interaction with tumor tissue, possibly altered by RhCE and CD47, resulting in a metastatic prone condition.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/sangre , Eritrocitos/metabolismo , Neoplasias Pulmonares/sangre , Estadificación de Neoplasias , Sistema del Grupo Sanguíneo Rh-Hr/biosíntesis , Biomarcadores de Tumor/biosíntesis , Biomarcadores de Tumor/sangre , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Progresión de la Enfermedad , Femenino , Alemania/epidemiología , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , Pronóstico , Tasa de Supervivencia/tendencias
11.
Clin Exp Metastasis ; 35(8): 777-783, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30324492

RESUMEN

Optimization of axillary staging among patients converting from clinically node-positive disease to clinically node-negative disease through primary systemic therapy is needed. We aimed at developing a nomogram predicting the probability of positive axillary status after chemotherapy based on clinical/pathological parameters. Patients from study arm C of the SENTINA trial were included. Univariable/multivariable analyses were performed for 13 clinical/pathological parameters to predict a positive pathological axillary status after chemotherapy using logistic regression models. Odds ratios and 95%-confidence-intervals were reported. Model performance was assessed by leave-one-out cross-validation. Calculations were performed using the SAS Software (Version 9.4, SAS Institute Inc., Cary, NC, USA). 369 of 553 patients in Arm C were included in multivariable analysis. Stepwise backward variable selection based on a multivariable analysis resulted in a model including estrogen receptor (ER) status (odds ratio (OR) 3.916, 95% confidence interval (CI) 2.318-6.615, p < 0.001), multifocality (OR 2.106, 95% CI 1.203-3.689, p = 0.0092), lymphovascular invasion (OR 9.196, 95% CI 4.734-17.864, p < 0.001), and sonographic tumor diameter after PST (OR 1.034, 95% CI 1.010-1.059, p = 0.0051). When validated, our model demonstrated an accuracy of 70.2% using 0.5 as cut-point. An area under the curve of 0.81 was calculated. The use of individual parameters as predictors of lymph node status after chemotherapy resulted in an inferior accuracy. Our model was able to predict the probability of a positive axillary nodal status with a high accuracy. The use of individual parameters showed reduced predictive performance. Overall, tumor biology was the strongest parameter in our models.


Asunto(s)
Neoplasias de la Mama/patología , Metástasis Linfática/patología , Estadificación de Neoplasias/métodos , Nomogramas , Adulto , Anciano , Antineoplásicos/uso terapéutico , Área Bajo la Curva , Axila , Neoplasias de la Mama/tratamiento farmacológico , Quimioterapia Adyuvante , Femenino , Humanos , Metástasis Linfática/diagnóstico , Persona de Mediana Edad , Terapia Neoadyuvante , Curva ROC , Ganglio Linfático Centinela/patología , Biopsia del Ganglio Linfático Centinela
12.
Curr Biol ; 9(1): 47-50, 1999 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-9889126

RESUMEN

Active transport between nucleus and cytoplasm proceeds through nuclear pore complexes (NPCs) and is mediated largely by shuttling transport receptors that use direct RanGTP binding to coordinate loading and unloading of cargo [1] [2] [3] [4]. Import receptors such as importin beta or transportin bind their substrates at low RanGTP levels in the cytoplasm and release them upon encountering RanGTP in the nucleus, where a high RanGTP concentration is predicted. This substrate release is, in the case of import by the importin alpha/beta heterodimer, coupled directly to importin beta release from the NPCs. If the importin beta -RanGTP interaction is prevented, import intermediates arrest at the nuclear side of the NPCs [5] [6]. This arrest makes it difficult to probe directly the Ran and energy requirements of the actual translocation from the cytoplasmic to the nuclear side of the NPC, which immediately precedes substrate release. Here, we have shown that in the case of transportin, dissociation of transportin-substrate complexes is uncoupled from transportin release from NPCs. This allowed us to dissect the requirements of translocation through the NPC, substrate release and transportin recycling. Surprisingly, translocation of transportin-substrate complexes into the nucleus requires neither Ran nor nucleoside triphosphates (NTPs). It is only nuclear RanGTP, not GTP hydrolysis, that is needed for dissociation of transportin-substrate complexes and for re-export of transportin to the cytoplasm. GTP hydrolysis is apparently required only to restore the import competence of the re-exported transportin and, thus, for multiple rounds of transportin-dependent import. In addition, we provide evidence that at least one type of substrate can also complete NPC passage mediated by importin beta independently of Ran and energy.


Asunto(s)
Guanosina Trifosfato/metabolismo , Membrana Nuclear/metabolismo , Proteínas Nucleares/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Hidrólisis , Carioferinas , Microscopía Confocal , Ciclo del Sustrato , Proteína de Unión al GTP ran
13.
Curr Biol ; 10(8): 467-70, 2000 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-10801418

RESUMEN

Histone acetylases were originally identified because of their ability to acetylate histone substrates [1] [2] [3]. Acetylases can also target other proteins such as transcription factors [4] [5] [6] [7]. We asked whether the acetylase CREB-binding protein (CBP) could acetylate proteins not directly involved in transcription. A large panel of proteins, involved in a variety of cellular processes, were tested as substrates for recombinant CBP. This screen identified two proteins involved in nuclear import, Rch1 (human importin-alpha) and importin-alpha7, as targets for CBP. The acetylation site within Rch1 was mapped to a single residue, Lys22. By comparing the context of Lys22 with the sequences of other known substrates of CBP and the closely related acetylase p300, we identified G/SK (in the single-letter amino acid code) as a consensus acetylation motif. Mutagenesis of the glycine, as well as the lysine, severely impaired Rch1 acetylation, supporting the view that GK is part of a recognition motif for acetylation by CBP/p300. Using an antibody raised against an acetylated Rch1 peptide, we show that Rch1 was acetylated at Lys22 in vivo and that CBP or p300 could mediate this reaction. Lys22 lies within the binding site for a second nuclear import factor, importin-beta. Acetylation of Lys22 promoted interaction with importin-beta in vitro. Collectively, these results demonstrate that acetylation is not unique to proteins involved in transcription. Acetylation may regulate a variety of biological processes, including nuclear import.


Asunto(s)
Proteínas Portadoras/metabolismo , Proteínas Nucleares/metabolismo , Transactivadores/metabolismo , alfa Carioferinas , Acetilación , Acetiltransferasas/metabolismo , Secuencia de Aminoácidos , Sitios de Unión , Proteína de Unión a CREB , Proteínas Portadoras/química , Proteínas de Ciclo Celular/metabolismo , Línea Celular , Secuencia de Consenso , Glicina/química , Glicina/genética , Histona Acetiltransferasas , Humanos , Carioferinas , Lisina/química , Lisina/genética , Datos de Secuencia Molecular , Mutación , Proteínas Nucleares/química , Proteínas Nucleares/genética , Alineación de Secuencia , Transactivadores/química , Transactivadores/genética , Factores de Transcripción , Transformación Genética , Factores de Transcripción p300-CBP
14.
Curr Biol ; 5(4): 383-92, 1995 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-7627554

RESUMEN

BACKGROUND: Selective protein import into the cell nucleus occurs in two steps: binding to the nuclear envelope, followed by energy-dependent transit through the nuclear pore complex. A 60 kD protein, importin, is essential for the first nuclear import step, and the small G protein Ran/TC4 is essential for the second. We have previously purified the 60kD importin protein (importin 60) as a single polypeptide. RESULTS: We have identified importin 90, a 90 kD second subunit that dissociates from importin 60 during affinity chromatography on nickel (II)-nitrolotriacetic acid-Sepharose, a technique that was originally used to purify importin 60. Partial amino-acid sequencing of Xenopus importin 90 allowed us to clone and sequence its human homologue; the amino-acid sequence of importin 90 is strikingly conserved between the two species. We have also identified a homologous budding yeast sequence from a database entry. Importin 90 potentiates the effects of importin 60 on nuclear protein import, indicating that the importin complex is the physiological unit responsible for import. To assess whether nuclear localization sequences are recognized by cytosolic receptor proteins, a biotin-tagged conjugate of nuclear localization signals linked to bovine serum albumin was allowed to form complexes with cytosolic proteins in Xenopus egg extracts; the complexes were then retrieved with streptavidin-agarose. The pattern of bound proteins was surprisingly simple and showed only two predominant bands: those of the importin complex. We also expressed the human homologue of importin 60, Rch1p, and found that it was able to replace its Xenopus counterpart in a functional assay. We discuss the relationship of importin 60 and importin 90 to other nuclear import factors. CONCLUSIONS: Importin consists of a 60 and a 90 kD subunit. Together, they constitute a cytosolic receptor for nuclear localization signals that enables import substrates to bind to the nuclear envelope.


Asunto(s)
Membrana Nuclear/metabolismo , Proteínas Nucleares/metabolismo , alfa Carioferinas , Secuencia de Aminoácidos , Animales , Evolución Biológica , Transporte Biológico , Proteínas Portadoras/metabolismo , Clonación Molecular , Citosol/metabolismo , Células HeLa , Humanos , Carioferinas , Datos de Secuencia Molecular , Proteínas Nucleares/aislamiento & purificación , Unión Proteica , Señales de Clasificación de Proteína/metabolismo , Receptores Citoplasmáticos y Nucleares/metabolismo , Homología de Secuencia de Aminoácido , Xenopus
15.
Mol Cell Biol ; 17(9): 5087-96, 1997 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9271386

RESUMEN

We report the identification and characterization of a novel 124-kDa Ran binding protein, RanBP5. This protein is related to importin-beta, the key mediator of nuclear localization signal (NLS)-dependent nuclear transport. RanBP5 was identified by two independent methods: it was isolated from HeLa cells by using its interaction with RanGTP in an overlay assay to monitor enrichment, and it was also found by the yeast two-hybrid selection method with RanBP1 as bait. RanBP5 binds to RanBP1 as part of a trimeric RanBP1-Ran-RanBP5 complex. Like importin-beta, RanBP5 strongly binds the GTP-bound form of Ran, stabilizing it against both intrinsic and RanGAP1-induced GTP hydrolysis and also against nucleotide exchange. The GAP resistance of the RanBP5-RanGTP complex can be relieved by RanBP1, which might reflect an in vivo role for RanBP1. RanBP5 is a predominantly cytoplasmic protein that can bind to nuclear pore complexes. We propose that RanBP5 is a mediator of a nucleocytoplasmic transport pathway that is distinct from the importin-alpha-dependent import of proteins with a classical NLS.


Asunto(s)
Proteínas Fúngicas/metabolismo , Proteínas de Unión al GTP/metabolismo , Leucina Zippers , Proteínas Nucleares/química , Proteínas Nucleares/metabolismo , alfa Carioferinas/química , alfa Carioferinas/metabolismo , Secuencia de Aminoácidos , Clonación Molecular , Citoplasma/química , Proteínas de Unión al GTP/química , Proteínas de Unión al GTP/aislamiento & purificación , Guanosina Trifosfato/metabolismo , Células HeLa , Humanos , Hidrólisis , Datos de Secuencia Molecular , Membrana Nuclear/metabolismo , Proteínas Nucleares/aislamiento & purificación , Unión Proteica , Alineación de Secuencia , alfa Carioferinas/aislamiento & purificación , beta Carioferinas , Proteína de Unión al GTP ran
16.
Mol Cell Biol ; 19(11): 7782-91, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10523667

RESUMEN

Importin alpha plays a pivotal role in the classical nuclear protein import pathway. Importin alpha shuttles between nucleus and cytoplasm, binds nuclear localization signal-bearing proteins, and functions as an adapter to access the importin beta-dependent import pathway. In contrast to what is found for importin beta, several isoforms of importin alpha, which can be grouped into three subfamilies, exist in higher eucaryotes. We describe here a novel member of the human family, importin alpha7. To analyze specific functions of the distinct importin alpha proteins, we recombinantly expressed and purified five human importin alpha's along with importin alpha from Xenopus and Saccharomyces cerevisiae. Binding affinity studies showed that all importin alpha proteins from humans or Xenopus bind their import receptor (importin beta) and their export receptor (CAS) with only marginal differences. Using an in vitro import assay based on permeabilized HeLa cells, we compared the import substrate specificities of the various importin alpha proteins. When the substrates were tested singly, only the import of RCC1 showed a strong preference for one family member, importin alpha3, whereas most of the other substrates were imported by all importin alpha proteins with similar efficiencies. However, strikingly different substrate preferences of the various importin alpha proteins were revealed when two substrates were offered simultaneously.


Asunto(s)
Núcleo Celular/metabolismo , Factores de Intercambio de Guanina Nucleótido , Proteínas Nucleares/metabolismo , Acetiltransferasas/metabolismo , Secuencia de Aminoácidos , Transporte Biológico , Proteínas de Ciclo Celular/metabolismo , Sistema Libre de Células , Proteína de Susceptibilidad a Apoptosis Celular , Clonación Molecular , Proteínas de Unión al ADN/metabolismo , Evolución Molecular , GTP Fosfohidrolasas/metabolismo , Proteínas Activadoras de GTPasa/metabolismo , Ribonucleoproteínas Nucleares Heterogéneas , Histona Acetiltransferasas , Humanos , Carioferinas , Datos de Secuencia Molecular , Familia de Multigenes , Señales de Localización Nuclear , Proteínas Nucleares/clasificación , Nucleoplasminas , Fosfoproteínas/metabolismo , Unión Proteica , Isoformas de Proteínas/metabolismo , Proteínas/metabolismo , Ribonucleoproteínas/metabolismo , Análisis de Secuencia de ADN , Factores de Transcripción , Factores de Transcripción p300-CBP
17.
J Crohns Colitis ; 11(9): 1052-1062, 2017 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-28486634

RESUMEN

BACKGROUND AND AIM: Recent observational studies document that non-adherence to mesalamine therapy during remission is frequent. We aimed to investigate patient impact of patient education using objective assessments of adherence. METHODS: A 14-month randomised, prospective clinical trial of adherence to mesalamine was conducted in 248 patients with ulcerative colitis [UC], Colitis Activity Index [CAI] ≤ 9, receiving standard care [n = 122] versus a standardised patient education programme [n = 126]. Primary endpoint was adherence at all visits (5-aminosalicylic acid [5-ASA] urine levels). Secondary endpoints included quality of life (inflammatory bowel disease questionnaise [IBDQ]), disease activity, partial adherence, and self-assessment of adherence. RESULTS: Patient allocation was well balanced. Baseline non-adherence was high in quiescent/mildly active UC [52.4%] without difference between the groups (52.4% of patients in the education group versus 52.5% in the standard care group [p = 0.99]). No difference between the intervention group and standard care was seen in IBDQ, partial adherence, self-assessment of adherence, or therapy satisfaction at all visits. We suggest a model in which individual risks for non-adherence are driven by patients with young age, short disease duration, and low education levels. CONCLUSIONS: Non-adherence is frequent in a population with quiescent/mildly active UC. Although more than 25% of the population was not in remission at the various time points, no relationship between disease activity and adherence was seen over the 14-month observation period. Physicians should maximise their efforts to motivate high-risk patients for adherence. Future trials should use objective exposure assessments to examine the impact of continuous education and consultations on the background of individual risks to develop non-adherence.


Asunto(s)
Antiinflamatorios no Esteroideos/uso terapéutico , Colitis Ulcerosa/tratamiento farmacológico , Cumplimiento de la Medicación/estadística & datos numéricos , Mesalamina/uso terapéutico , Educación del Paciente como Asunto , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Colitis Ulcerosa/psicología , Femenino , Estudios de Seguimiento , Humanos , Modelos Logísticos , Masculino , Cumplimiento de la Medicación/psicología , Persona de Mediana Edad , Estudios Prospectivos , Calidad de Vida , Resultado del Tratamiento , Adulto Joven
18.
Handchir Mikrochir Plast Chir ; 48(4): 212-8, 2016 Aug.
Artículo en Alemán | MEDLINE | ID: mdl-27547929

RESUMEN

OBJECTIVE: Some patients with sacral scars, e. g. those developing after pilonidal sinus surgery, report discomfort when sitting or putting strain on the scars. In order to establish objective criteria for the assessment of this kind of discomfort and for the evaluation of scar quality after various types of surgical interventions, it is of interest to provide a method which enables physicians to assess skin quality in the sacral region. For this purpose, we developed a mechanical, non-invasive, fast and cost-neutral method for the measurement of skin distensibility and mobility. We examined a healthy sample of 100 study participants to establish benchmark values for scar-free skin in the sacral region and to identify the factors which impact skin quality, e. g. age, weight and sex. METHOD: With the participant in a standing position, 4 vertically arranged measurement points, which are exactly spaced in cranial to caudal direction by 10 mm-100 mm-10 mm, are marked in the lumbar and sacral region, respectively. The participant is then asked to bend forward and - with arms and legs fully stretched on both sides - to touch both their patellae with the balls of their hands so that the distance between the measurement points can be measured in this position as well. Then, with the participant standing upright again, another measurement is taken to establish the distance by which the lowest point can be manually moved in cranial direction. RESULTS: The sacral-lumbar skin distension quotient (lumbar skin distension / sacral skin distension×100), which can easily be calculated from the measurements, is independent of age and BMI and has a standard range of about 80-93%. Sacral skin mobility ranges from 11 to 18 mm, but is slightly negatively influenced by a high BMI. CONCLUSION: By comparing lumbar and sacral skin distension in the same study participant, we are able to obtain intraindividually valid findings about possible changes in skin and scar quality. Owing to the lack of known published data about sacral skin elasticity, the proposed measurement method, while restricted to a number of special cases, seems to be practicable and independent of the patient's general condition. Compared with devices that have been used for the measurement of elasticity in other skin areas, our procedure is generally available and cost-neutral.


Asunto(s)
Cicatriz , Sacro , Procedimientos Quirúrgicos Dermatologicos , Elasticidad , Humanos , Piel
19.
Bone Marrow Transplant ; 51(11): 1441-1448, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27295269

RESUMEN

Allogeneic stem cell transplantation (SCT) remains the best curative option for patients with refractory AML or with high-risk myelodysplastic syndrome (MDS). For decades, age alone had been widely used as the primary criterion to assess eligibility for allogeneic SCT; however, prospective studies to evaluate allogeneic SCT in elderly patients are still limited. A total of 187 patients (median age of 64 years, range 60-77 years) with AML (87%) or MDS (13%) transplanted between 1999 and 2014 were included in this retrospective analysis. Relapse-free survival (RFS) and overall survival (OS) at 3 years were 32% (95% confidence interval (CI): 25-39%) and 35% (95%CI: 27-42%), respectively. Overall survival was 49% (95%CI: 35-64%) in AML patients who were transplanted in first complete remission (CR1), but even patients with active disease did benefit from transplantation, showing an OS at 3 years of 30% (95%CI: 20-40%). Multivariate analysis revealed disease- and patient-specific risk indices as independent prognostic factors for OS and non-relapse mortality (NRM). In conclusion, our monocenter results indicate that patients should not be generally withheld from allogeneic SCT because of age or disease status only. Specific risk models incorporating disease status and disease-specific risk factors at the time of transplantation as well as existing comorbidities are helpful tools to assess transplantation-associated risk factors of elderly patients.


Asunto(s)
Trasplante de Células Madre Hematopoyéticas/métodos , Leucemia Mieloide Aguda/terapia , Síndromes Mielodisplásicos/terapia , Medición de Riesgo/métodos , Factores de Edad , Anciano , Femenino , Trasplante de Células Madre Hematopoyéticas/mortalidad , Humanos , Leucemia Mieloide Aguda/mortalidad , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/mortalidad , Estudios Retrospectivos , Análisis de Supervivencia , Trasplante Homólogo , Resultado del Tratamiento
20.
Lung Cancer ; 92: 8-14, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26775589

RESUMEN

OBJECTIVES: Several blood group-related carbohydrate antigens are prognosis-relevant markers of tumor tissues. A type 3 (repetitive A) is a blood group antigen specific for A1 erythrocytes. Its potential expression in tumor tissues has so far not been examined. MATERIAL AND METHODS: We have evaluated its expression in normal lung and in lung cancer using a novel antibody (A69-A/E8). For comparison an anti-A antibody specific to A types 1 and 2 was used, because its expression on lung cancer tissue has been previously reported to be of prognostic relevance. Resected tissue samples of 398 NSCLC patients were analyzed in immunohistochemistry using tissue microarrays. RESULTS AND CONCLUSIONS: Expression of A type 3 was not observed in non-malignant lung tissues. A type 3 was expressed on tumor cells of around half of NSCLC patients of blood group A1 (p<0.001). Whereas no prognostic effect for A type 1/2 antigen was observed (p=0.562), the expression of A type 3 by tumor cells indicated a highly significant favorable prognosis among advanced NSCLC patients (p=0.011) and in NSCLC patients with lymphatic spread (p=0.014). Univariate prognostic results were confirmed in a Cox proportional hazards model. In this study we present for the first time prognostic data for A type 3 antigen expression in lung cancer patients. Prospective studies should be performed to confirm the prognostic value of A type 3 expression for an improved risk stratification in NSCLC patients.


Asunto(s)
Antígenos de Neoplasias/sangre , Biomarcadores de Tumor/sangre , Antígenos de Grupos Sanguíneos/sangre , Carcinoma de Pulmón de Células no Pequeñas/sangre , Neoplasias Pulmonares/sangre , Anciano , Antígenos de Grupos Sanguíneos/biosíntesis , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Femenino , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología , Masculino , Pronóstico , Análisis de Supervivencia , Análisis de Matrices Tisulares
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