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1.
Eur J Clin Pharmacol ; 78(2): 259-265, 2022 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-34664109

RESUMEN

PURPOSE: Cannabichromene (CBC) is a phytocannabinoid commonly found in cannabis, yet its acute post-dose pharmacokinetics (PK) have not been examined in humans. This is a secondary data analysis from a trial investigating Spectrum Yellow oil, an oral cannabis product used for medical purposes that contained 20 mg cannabidiol (CBD), 0.9 mg Δ9-tetrahydrocannabinol (THC), and 1.1 mg CBC, per 1 mL of oil. METHODS: Participants (N = 43) were randomized to one of 5 groups: 120 mg CBD, 5.4 mg THC, and 6.6 mg CBC daily; 240 mg CBD, 10.8 mg THC, and 13.2 mg CBC daily; 360 mg CBD, 16.2 mg THC, and 19.8 mg CBC daily; 480 mg CBD, 21.6 mg THC, and 26.4 mg CBC daily; or placebo. Study medication was administered every 12 h for 7 days. Plasma CBC concentrations were analyzed by a validated two-dimensional high-performance liquid chromatography-tandem mass spectrometry assay. RESULTS: After a single dose and after the final dose, the Cmax of CBC increased by 1.3-1.8-fold for each twofold increase in dose; the tmax range was 1.6-4.3 h. Based on the ratio of administered CBD, THC, and CBC to the plasma concentration, the dose of CBD was 18 times higher than the dose of CBC, yet the AUC0-t of CBD was only 6.6-9.8-fold higher than the AUC0-t of CBC; the dose of THC was similar to the dose of CBC, yet THC was quantifiable in fewer plasma samples than was CBC. CONCLUSIONS: CBC may have preferential absorption over CBD and THC when administered together. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry #ACTRN12619001450101, registered 18 October 2019.


Asunto(s)
Cannabidiol/farmacocinética , Cannabinoides/farmacocinética , Dronabinol/farmacocinética , Marihuana Medicinal/farmacocinética , Área Bajo la Curva , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Humanos , Proyectos Piloto
2.
BMC Neurol ; 20(1): 248, 2020 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-32552792

RESUMEN

BACKGROUND: COVID-19 is caused by the severe acute respiratory syndrome virus SARS-CoV-2. It is widely recognized as a respiratory pathogen, but neurologic complications can be the presenting manifestation in a subset of infected patients. CASE PRESENTATION: We describe a 78-year old immunocompromised woman who presented with altered mental status after witnessed seizure-like activity at home. She was found to have SARS-CoV-2 infection and associated neuroinflammation. In this case, we undertake the first detailed analysis of cerebrospinal fluid (CSF) cytokines during COVID-19 infection and find a unique pattern of inflammation in CSF, but no evidence of viral neuroinvasion. CONCLUSION: Our findings suggest that neurologic symptoms such as encephalopathy and seizures may be the initial presentation of COVID-19. Central nervous system inflammation may associate with neurologic manifestations of disease.


Asunto(s)
Betacoronavirus , Infecciones por Coronavirus , Citocinas/líquido cefalorraquídeo , Encefalitis Viral , Pandemias , Neumonía Viral , Enfermedad Aguda , Anciano , Biomarcadores/líquido cefalorraquídeo , COVID-19 , Femenino , Humanos , SARS-CoV-2 , Convulsiones
3.
Nature ; 452(7189): 872-6, 2008 Apr 17.
Artículo en Inglés | MEDLINE | ID: mdl-18421352

RESUMEN

The association of genetic variation with disease and drug response, and improvements in nucleic acid technologies, have given great optimism for the impact of 'genomic medicine'. However, the formidable size of the diploid human genome, approximately 6 gigabases, has prevented the routine application of sequencing methods to deciphering complete individual human genomes. To realize the full potential of genomics for human health, this limitation must be overcome. Here we report the DNA sequence of a diploid genome of a single individual, James D. Watson, sequenced to 7.4-fold redundancy in two months using massively parallel sequencing in picolitre-size reaction vessels. This sequence was completed in two months at approximately one-hundredth of the cost of traditional capillary electrophoresis methods. Comparison of the sequence to the reference genome led to the identification of 3.3 million single nucleotide polymorphisms, of which 10,654 cause amino-acid substitution within the coding sequence. In addition, we accurately identified small-scale (2-40,000 base pair (bp)) insertion and deletion polymorphism as well as copy number variation resulting in the large-scale gain and loss of chromosomal segments ranging from 26,000 to 1.5 million base pairs. Overall, these results agree well with recent results of sequencing of a single individual by traditional methods. However, in addition to being faster and significantly less expensive, this sequencing technology avoids the arbitrary loss of genomic sequences inherent in random shotgun sequencing by bacterial cloning because it amplifies DNA in a cell-free system. As a result, we further demonstrate the acquisition of novel human sequence, including novel genes not previously identified by traditional genomic sequencing. This is the first genome sequenced by next-generation technologies. Therefore it is a pilot for the future challenges of 'personalized genome sequencing'.


Asunto(s)
Variación Genética/genética , Genoma Humano/genética , Genómica/métodos , Análisis de Secuencia de ADN/métodos , Alelos , Biología Computacional , Predisposición Genética a la Enfermedad/genética , Genómica/economía , Genómica/tendencias , Genotipo , Humanos , Individualidad , Masculino , Análisis de Secuencia por Matrices de Oligonucleótidos , Polimorfismo de Nucleótido Simple/genética , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Alineación de Secuencia , Análisis de Secuencia de ADN/economía , Programas Informáticos
4.
J Int Soc Sports Nutr ; 20(1): 2280113, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37947792

RESUMEN

BACKGROUND: Cannabinoid-containing products are marketed to athletes as promoting recovery, in spite of a lack of data on their safety and effects. This randomized, double-blind, placebo-controlled, repeated-dose pilot study tested the safety, tolerability, and preliminary effects on recovery of a formulation containing cannabidiol (CBD; 35 mg), cannabigerol (CBG; 50 mg), beta caryophyllene (BCP; 25 mg), branched-chain amino acids (BCAAs; 3.8 g), and magnesium citrate (420 mg). METHODS: Exercise-trained individuals (N = 40) underwent an experimental induction of delayed onset muscle soreness (DOMS) and completed follow-up visits 24-, 48-, and 72-hours post-DOMS. Participants were randomized to active or placebo formulation, and consumed the formulation twice per day for 3.5 days. RESULTS: There was one adverse event (AE) in the active group (diarrhea) and two AEs in placebo (dry mouth; eye rash/swollen eye). There was 100% self-reported compliance with formulation consumption across the two groups. For the primary outcome of interest, the estimate of effect for ratings of average soreness/discomfort 72 hours post-DOMS between active and placebo groups was -1.33 (85% confidence interval = -2.55, -0.10), suggesting moderate evidence of a treatment difference. The estimate of effect for the outcome of ratings of interference of soreness, discomfort, or stiffness on daily activities at work or home 48 hours post-DOMS was -1.82 (95% confidence interval = -3.64, -0.01), indicating a treatment difference of potential clinical importance. There was no significant effect between active and placebo groups on objective measures of recovery, sleep quality, or mood disturbance. CONCLUSIONS: The tested formulation reduced interference of DOMS on daily activities, demonstrating its improvement on a functional aspect of recovery.


Asunto(s)
Cannabidiol , Mialgia , Humanos , Mialgia/tratamiento farmacológico , Cannabidiol/uso terapéutico , Proyectos Piloto , Polvos
5.
Cannabis Cannabinoid Res ; 8(S1): S71-S82, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37721990

RESUMEN

Introduction: Tetrahydrocannabivarin (THCV) is an understudied cannabinoid that appears to have effects that vary as a function of dose. No human study has evaluated the safety and nature of effects in a wide range of THCV doses. Methods: This was a two-phase, dose-ranging, placebo-controlled trial of the Δ8 isomer of oral THCV in healthy adults. Phase 1 utilized an unblinded, single-ascending dose design (n=3). Phase 2 used a double-blind, randomized, within-participant crossover design (n=18). Participants received single acute doses of placebo and 12.5, 25, 50, 100, and 200 mg of THCV. Safety measures and subjective and cognitive effects were assessed predose and up to 8 h postdose. Results: Most adverse events (AEs; 55/60) were mild. Euphoric mood was the most common AE. The 12.5, 25, and 200 mg doses produced significantly lower minimum times to complete the digit vigilance test (ps=0.01). The 25 mg dose showed elevations on mean ratings of "energetic" at 1-, 2-, and 4-h postdose, but the maximum postdose rating for this dose did not achieve statistical significance relative to placebo ([95% confidence interval]=3.2 [-0.5 to 6.9], p=0.116). The 100 and 200 mg doses showed elevations on ratings of "feel a drug effect" and "like the drug effect." Almost all urine drug screens (78/79) at 8 h postdose in the active THCV conditions tested positive for tetrahydrocannabinol (THC). Conclusion: All THCV doses displayed a favorable safety profile. Several THCV doses showed a preliminary signal for improved sustained attention, but the effect was not dose dependent. Though mild and not associated with impairment, THC-like effects were observed at higher THCV doses. Oral THCV-containing products could lead to positive urine drug screens for THC. ClinicalTrials.gov ID: NCT05210634.


Asunto(s)
Cannabinoides , Emociones , Adulto , Humanos , Voluntarios Sanos , Método Doble Ciego , Euforia
6.
Cannabis Cannabinoid Res ; 8(S1): S83-S89, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37721991

RESUMEN

Introduction: Cannabidiol (CBD), a nonintoxicating cannabinoid, may be involved in bone remodeling, but human studies are limited. In this case series, we explored the effects of oral CBD administration on bone turnover. Materials and Methods: Two postmenopausal women with osteopenia (T-score=-1 to -2.5) were randomized to receive 100 or 300 mg CBD daily (oral, bis in die [twice per day]) for 12 weeks. Serum markers of bone resorption (carboxyl-terminal collagen crosslinks [CTx]) and bone formation (procollagen type 1 N-terminal propeptide [P1NP], bone-specific alkaline phosphatase [BSAP], and osteocalcin [OC]); safety measures; plasma concentrations of CBD and metabolites; sleep disturbance; symptoms of depression, anxiety, and stress; and quality of life, were assessed. Results: CBD was well tolerated, with no clinically significant change in vital signs, hematology, chemistry, or urinalysis, and no adverse events reported. Reductions (% change vs. baseline) in CTx (-8.5%, -28.1%), P1NP (-9.9%, -39.5%), BSAP (-12.7%, -74.8%), and OC (-16.0%, -6.7%) were observed after 12 weeks of oral administration of 100 or 300 mg CBD daily, respectively. The two participants self-reported consuming 95.3% and 98.8% of CBD doses, respectively. CBD and select metabolites were measurable in plasma after 4 and 12 weeks of CBD treatment. No notable changes in sleep disturbance, depression, anxiety, stress, or quality of life were observed. Conclusions: CBD was well tolerated after 12 weeks of twice-daily oral administration and was associated with reduction in measured markers of bone turnover. Compliance with CBD treatment was good. Large-scale randomized clinical trials into the bone protective effects of CBD in postmenopausal women are warranted.


Asunto(s)
Enfermedades Óseas Metabólicas , Cannabidiol , Humanos , Femenino , Cannabidiol/farmacología , Cannabidiol/uso terapéutico , Posmenopausia , Calidad de Vida , Enfermedades Óseas Metabólicas/tratamiento farmacológico , Administración Oral , Fosfatasa Alcalina , Osteocalcina
7.
J Anal Toxicol ; 46(4): 393-407, 2022 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-33710277

RESUMEN

Due to a lack of published pharmacokinetic (PK) and/or pharmacodynamic (PD) data, decision-making surrounding appropriate dosing of cannabis used for medical purposes is limited. This multiple-dose study evaluated the safety, tolerability, PK and PD of Spectrum Yellow oil [20 mg/mL cannabidiol (CBD)/<1 mg/mL ∆9-tetrahydrocannabinol (THC)]. Participants (n = 43) were randomized to one of five groups: 120 mg CBD and 5.4 mg THC daily, 240 mg CBD and 10.8 mg THC daily, 360 mg CBD and 16.2 mg THC daily, 480 mg CBD and 21.6 mg THC daily or placebo. Study medication was administered every 12 h for 7 consecutive days. Treatment-emergent adverse events (TEAEs); plasma and urine concentrations of THC, CBD and metabolites; and self-reported subjective effects were collected. Nearly all TEAEs (44/45) were of mild or moderate severity; none was serious. The highest incidence of TEAEs (67%) was in the two higher-dose treatment groups. The highest number of TEAEs (17/45) occurred on the first treatment day. Steady-state plasma CBD concentrations were reached by Day 7. On Day 7, CBD exposure showed dose proportionality (AUC0-t slope = 1.03 [0.70, 1.36], Cmax slope = 0.92 [0.53, 1.31]). Most plasma THC concentrations were below the limit of quantification. Across Days 1 and 7, there were no consistent differences in subjective effects between placebo and active study medication. A prudent approach to improve tolerability with Spectrum Yellow oil might involve initial doses no higher than 240 mg total CBD and 10.8 mg total THC daily in divided doses, with titration upward over time as needed based on tolerability.


Asunto(s)
Cannabidiol , Cannabis , Analgésicos , Cannabidiol/farmacocinética , Dronabinol/farmacocinética , Voluntarios Sanos , Humanos
8.
J Anal Toxicol ; 46(5): 528-539, 2022 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-33848338

RESUMEN

Due to a lack of published pharmacokinetic (PK) and/or pharmacodynamic (PD) data, informed physician and patient decision-making surrounding appropriate dosing of cannabis for medical purposes is limited. This Phase 1, multiple-dose study evaluated the safety, tolerability, PK and PD of Spectrum Red softgels (2.5 mg Δ9-tetrahydrocannabinol (THC) and <0.25 mg cannabidiol (CBD)). Participants (n = 41) were randomized to one of five groups: 5 mg THC and 0.06 mg CBD daily (Treatment A), 10 mg THC and 0.12 mg CBD daily (Treatment B), 15 mg THC and 0.18 mg CBD daily (Treatment C), 20 mg THC and 0.24 mg CBD daily (Treatment D) or placebo. Study medication was administered in divided doses, every 12 h, ∼60 min after a standardized meal, for 7 consecutive days. All treatment-emergent adverse events (TEAEs) (65/65) were of mild-to-moderate severity; none was serious. The highest number of TEAEs (30/65) occurred on the first day of treatment. The most common TEAEs included somnolence, lethargy and headache (reported by eight, seven and five participants, respectively). On Day 7, maximum observed plasma concentration of 11-carboxy-THC increased by 2.0- and 2.5-fold as the dose doubled between Treatments A and B and between Treatments B and D, respectively. Mean peak post-treatment ratings of self-reported subjective effects of 'feel any effect' and 'dazed' differed between Treatment D and placebo on Days 1, 3 and 7. Over a week of twice-daily dosing of Spectrum Red softgels, daily doses of THC up to 20 mg and of CBD up to 0.24 mg were generally safe and became better tolerated after the first day of treatment. A prudent approach to improve tolerability with Spectrum Red softgels might involve initial daily doses no higher than 10 mg THC and 0.12 mg CBD in divided doses, with titration upward over time as needed based on tolerability.


Asunto(s)
Cannabidiol , Cannabis , Analgésicos , Cannabidiol/farmacocinética , Dronabinol , Voluntarios Sanos , Humanos
9.
Res Sq ; 2020 May 12.
Artículo en Inglés | MEDLINE | ID: mdl-32702723

RESUMEN

BACKGROUND: COVID-19 is caused by the severe acute respiratory syndrome virus SARS-CoV-2. It is widely recognized as a respiratory pathogen, but neurologic complications can be the presenting manifestation in a subset of infected patients. CASE PRESENTATION: We describe a 78-year old immunocompromised woman who presented with altered mental status after witnessed seizure-like activity at home. She was found to have SARS-CoV-2 infection and associated neuroinflammation. In this case, we undertake the first detailed analysis of cerebrospinal fluid (CSF) cytokines during COVID-19 infection and find a unique pattern of inflammation in CSF, but no evidence of viral neuroinvasion. CONCLUSION: Our findings suggest that neurologic symptoms such as encephalopathy and seizures may be the initial presentation of COVID-19. Central nervous system inflammation may associate with neurologic manifestations of disease.

10.
FEMS Yeast Res ; 9(8): 1250-9, 2009 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19686339

RESUMEN

Yeasts have evolved numerous responsive pathways to survive in fluctuating and stressful environments. The endoplasmic reticulum (ER) is sensitive to adverse conditions, which are detected by response pathways to ensure correct protein folding. Calnexin is an ER transmembrane chaperone acting in both quality control of folding and response to persistent stress. Calnexin is a key protein required for viability in certain organisms such as mammals and the fission yeast Schizosaccharomyces pombe. Nevertheless, S. pombe calnexin-independent (Cin) cells were obtained after transient expression of a particular calnexin mutant. The Cin state is dominant, is stably propagated by an epigenetic mechanism and segregates in a non-Mendelian fashion to the meiotic progeny. The nucleolar protein Cif1p was identified as an inducer of the Cin state in a previous genetic screen. Here, we report the identification of novel inducers isolated in an overexpression genetic screen: pyruvate kinase (Pyk1p) and phosphoglycerate kinase (Pgk1p). Addition of pyruvate, the end product of pyruvate kinase and glycolysis, also induced calnexin independence in a dose-dependent manner. Remarkably, growth in respiration media or cold temperatures induced the appearance of Cin cells at high frequencies. Taken together, our results indicate that the Cin state can be triggered by extracellular changes, suggesting that this state represents an epigenetic adaptative response to environmental modifications.


Asunto(s)
Adaptación Fisiológica , Calnexina/metabolismo , Epigénesis Genética , Regulación Fúngica de la Expresión Génica , Viabilidad Microbiana , Schizosaccharomyces/fisiología , Calnexina/genética , Frío , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Dosificación de Gen , Mutación , Ácido Pirúvico/metabolismo
11.
PLoS One ; 5(5): e10612, 2010 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-20485525

RESUMEN

The current paradigm for elucidating the molecular etiology of cancers relies on the interrogation of small numbers of genes, which limits the scope of investigation. Emerging second-generation massively parallel DNA sequencing technologies have enabled more precise definition of the cancer genome on a global scale. We examined the genome of a human primary malignant pleural mesothelioma (MPM) tumor and matched normal tissue by using a combination of sequencing-by-synthesis and pyrosequencing methodologies to a 9.6X depth of coverage. Read density analysis uncovered significant aneuploidy and numerous rearrangements. Method-dependent informatics rules, which combined the results of different sequencing platforms, were developed to identify and validate candidate mutations of multiple types. Many more tumor-specific rearrangements than point mutations were uncovered at this depth of sequencing, resulting in novel, large-scale, inter- and intra-chromosomal deletions, inversions, and translocations. Nearly all candidate point mutations appeared to be previously unknown SNPs. Thirty tumor-specific fusions/translocations were independently validated with PCR and Sanger sequencing. Of these, 15 represented disrupted gene-encoding regions, including kinases, transcription factors, and growth factors. One large deletion in DPP10 resulted in altered transcription and expression of DPP10 transcripts in a set of 53 additional MPM tumors correlated with survival. Additionally, three point mutations were observed in the coding regions of NKX6-2, a transcription regulator, and NFRKB, a DNA-binding protein involved in modulating NFKB1. Several regions containing genes such as PCBD2 and DHFR, which are involved in growth factor signaling and nucleotide synthesis, respectively, were selectively amplified in the tumor. Second-generation sequencing uncovered all types of mutations in this MPM tumor, with DNA rearrangements representing the dominant type.


Asunto(s)
Genoma Humano/genética , Mesotelioma/genética , Neoplasias Pleurales/genética , Análisis de Secuencia de ADN/métodos , Aberraciones Cromosómicas , Mapeo Cromosómico , Cromosomas Humanos Par 21/genética , ADN de Neoplasias/genética , Regulación Neoplásica de la Expresión Génica , Reordenamiento Génico/genética , Genes Relacionados con las Neoplasias/genética , Humanos , Mutación INDEL/genética , Cariotipificación , Mutación Puntual/genética , Polimorfismo de Nucleótido Simple/genética , Estándares de Referencia , Reproducibilidad de los Resultados
12.
J Cell Sci ; 122(Pt 9): 1342-51, 2009 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-19351719

RESUMEN

In fission yeast, the ER-residing molecular chaperone calnexin is normally essential for viability. However, a specific mutant of calnexin that is devoid of chaperone function (Deltahcd_Cnx1p) induces an epigenetic state that allows growth of Schizosaccharomyces pombe without calnexin. This calnexin-independent (Cin) state was previously shown to be mediated via a non-chromosomal element exhibiting some prion-like features. Here, we report the identification of a gene whose overexpression induces the appearance of stable Cin cells. This gene, here named cif1(+) for calnexin-independence factor 1, encodes an uncharacterized nucleolar protein. The Cin cells arising from cif1(+) overexpression (Cin(cif1) cells) are genetically and phenotypically distinct from the previously characterized Cin(Deltahcd_cnx1) cells, which spontaneously appear in the presence of the Deltahcd_Cnx1p mutant. Moreover, cif1(+) is not required for the induction or maintenance of the Cin(Deltahcd_cnx1) state. These observations argue for different pathways of induction and/or maintenance of the state of calnexin independence. Nucleolar localization of Cif1p is required to induce the Cin(cif1) state, thus suggesting an unexpected interaction between the vital cellular role of calnexin and a function of the nucleolus.


Asunto(s)
Calnexina/metabolismo , Nucléolo Celular/metabolismo , Supervivencia Celular , Retículo Endoplásmico/metabolismo , Chaperonas Moleculares/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Secuencia de Aminoácidos , Calnexina/genética , Chaperonas Moleculares/genética , Datos de Secuencia Molecular , Mutación , Proteínas Nucleares/genética , Fenotipo , Schizosaccharomyces/citología , Schizosaccharomyces/genética , Schizosaccharomyces/metabolismo , Proteínas de Schizosaccharomyces pombe/genética
13.
Nat Med ; 15(11): 1322-6, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19820716

RESUMEN

Major histocompatibility complex (MHC) genetics dictate adaptive cellular immune responses, making robust MHC genotyping methods essential for studies of infectious disease, vaccine development and transplantation. Nonhuman primates provide essential preclinical models for these areas of biomedical research. Unfortunately, given the unparalleled complexity of macaque MHCs, existing methodologies are inadequate for MHC typing of these key model animals. Here we use pyrosequencing of complementary DNA-PCR amplicons as a general approach to determine comprehensive MHC class I genotypes in nonhuman primates. More than 500 unique MHC class I sequences were resolved by sequence-based typing of rhesus, cynomolgus and pig-tailed macaques, nearly half of which have not been reported previously. The remarkable sensitivity of this approach in macaques demonstrates that pyrosequencing is viable for ultra-high-throughput MHC genotyping of primates, including humans.


Asunto(s)
Antígenos de Histocompatibilidad Clase I/genética , Antígenos de Histocompatibilidad Clase I/metabolismo , Animales , Secuencia de Bases , ADN/genética , Genotipo , Macaca fascicularis , Macaca mulatta , Macaca nemestrina , Datos de Secuencia Molecular , Polimorfismo Genético/genética , Homología de Secuencia de Aminoácido
14.
FEMS Yeast Res ; 7(2): 196-208, 2007 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-17328741

RESUMEN

In the yeast Schizosaccharomyces pombe, the molecular chaperone calnexin (Cnx1p) has been shown to be essential for viability. However, we recently reported that, under certain circumstances, S. pombe cells are able to survive in the absence of calnexin/Cnx1p, indicating that an inducible pathway can complement the calnexin/Cnx1p essential function(s). This calnexin-independent state (Cin) is transmitted by a nonchromosomal proteinaceous element exhibiting several prion-like properties. To assess to what extent the Cin state compensates for the absence of calnexin/Cnx1p, the Cin strain was further characterized. Cin cells exhibited cell-wall defects, sensitivity to heat shock, as well as higher secretion levels of a model glycoprotein. Together, these results indicate that the Cin state does not compensate for all calnexin/Cnx1p functions. Reintroduction of plasmid-borne cnx1(+) partially rescued most but not all of the phenotypes displayed by Cin cells. Interestingly, Cin cells in stationary phase exhibited increased levels of caspase activation, and this phenotype was not suppressed by the reintroduction of cnx1(+), suggesting that cells in the Cin state are subjected to a stress other than the absence of calnexin/Cnx1p.


Asunto(s)
Calnexina/metabolismo , Respuesta al Choque Térmico , Mutación , Priones/metabolismo , Proteínas de Schizosaccharomyces pombe/metabolismo , Schizosaccharomyces/fisiología , Calnexina/genética , Caspasas/metabolismo , Medios de Cultivo , Activación Enzimática , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Pliegue de Proteína , Schizosaccharomyces/enzimología , Schizosaccharomyces/crecimiento & desarrollo , Schizosaccharomyces/metabolismo
15.
Dev Dyn ; 224(1): 51-7, 2002 May.
Artículo en Inglés | MEDLINE | ID: mdl-11984873

RESUMEN

Dorsoventral patterning of the Drosophila embryo requires Nudel, a large mosaic protein with a protease domain. Previous studies have implicated Nudel's protease domain as the trigger of a proteolytic cascade that activates the Toll signaling pathway to establish dorsoventral polarity in the embryo. However, the function of other regions of Nudel has been unclear. By using two-dimensional gel electrophoresis and site-directed mutagenesis, we have obtained evidence that the N-terminal region of Nudel contains a site for glycosaminoglycan (GAG) attachment that is required for dorsoventral patterning. Disruption of this site blocks a disulfide-based association between N- and C-terminal Nudel polypeptides and proteolytic activation of Nudel's protease domain. We discuss how a GAG chain on Nudel might be required for Nudel protease activation.


Asunto(s)
Tipificación del Cuerpo , Proteínas de Drosophila , Drosophila melanogaster/embriología , Glicosaminoglicanos/metabolismo , Serina Endopeptidasas/metabolismo , Animales , Drosophila melanogaster/anatomía & histología , Drosophila melanogaster/genética , Electroforesis en Gel Bidimensional , Femenino , Mutagénesis Sitio-Dirigida , Ovario/citología , Ovario/metabolismo , Serina Endopeptidasas/genética , Transgenes
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