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1.
J Cancer Res Clin Oncol ; 148(10): 2569-2579, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34618220

RESUMEN

BACKGROUND: Adding neoadjuvant chemotherapy (NAC) to concurrent chemoradiotherapy (CCRT) is the main strategy in treatment of children and adolescents with locoregionally advanced nasopharyngeal carcinoma (CA-LANPC). Yet, an optimal number of NAC cycles remains unknown. We aimed to optimize the NAC cycle and potentially contribute to clinical decision making for the individual treatment of CA-LANPC. PATIENTS AND METHODS: Utilizing an NPC-specific database through an acknowledged big-data information system at our center, we identified 143 CA-LANPC treated with NAC followed by CCRT between September 2007 through April 2018. Recursive partitioning analysis (RPA) was performed to categorize the patients and predict disease-free survival (DFS). The clinical benefits of NAC cycles (two cycles vs three cycles) were assessed in each risk group. RESULTS: Independent factors derived from multivariable analysis to predict DFS were T stage (T1-3 vs T4) and plasma Epstein-Barr virus (EBV) DNA (< 4000 vs ≥ 4000 copies/mL) for risk stratification. Consequently, 87 (61%) participants were classified as low-risk group (T1-3 with low or high EBV DNA, and T4 with low EBV DNA) and the other 56 patients (39%) were classified as a high-risk group (T4 with high EBV DNA) through RPA, and corresponding 5-year DFS rates of 91.9% and 71.2%, respectively (p = 0.001). Among the high-risk group, patients receiving three cycles of NAC had statistically significant improvement in 5-year DFS over those who received two cycles of NAC (86.7% vs 59.1%; p = 0.020), while the survival benefit of three cycles NAC for low-risk groups were not observed (94.7% vs 89.7%; p = 0.652). CONCLUSIONS: We found three cycles of NAC with CCRT was a positive prognostic indicator for improved DFS for the high-risk group among CA-LANPC. However, whether low-risk patients could benefit from three cycles NAC needs further study.


Asunto(s)
Infecciones por Virus de Epstein-Barr , Neoplasias Nasofaríngeas , Adolescente , Quimioradioterapia/efectos adversos , Niño , Infecciones por Virus de Epstein-Barr/etiología , Herpesvirus Humano 4 , Humanos , Carcinoma Nasofaríngeo/tratamiento farmacológico , Neoplasias Nasofaríngeas/tratamiento farmacológico , Terapia Neoadyuvante
2.
World J Clin Cases ; 9(17): 4188-4198, 2021 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-34141781

RESUMEN

BACKGROUND: Cervical cancer is the fourth commonest malignancy in women around the world. It represents the second most commonly diagnosed cancer in South East Asian women, and an important cancer death cause in women of developing nations. Data collected in 2018 revealed 5690000 cervical cancer cases worldwide, 85% of which occurred in developing countries. AIM: To assess self-perceived burden (SPB) and related influencing factors in cervical cancer patients undergoing radiotherapy. METHODS: Patients were prospectively included by convenient sampling at The Fifth Affiliated Hospital of Sun Yat-Sen University, China between March 2018 and March 2019. The survey was completed using a self-designed general information questionnaire, the SPB scale for cancer patients, and the self-care self-efficacy scale, Strategies Used by People to Promote Health, which were delivered to patients with cervical cancer undergoing radiotherapy. Measurement data are expressed as the mean ± SD. Enumeration data are expressed as frequencies or percentages. Caregivers were the spouse, offspring, and other in 46.4, 40.9, and 12.7%, respectively, and the majority were male (59.1%). As for pathological type, 90 and 20 cases had squamous and adenocarcinoma/adenosquamous carcinomas, respectively. Stage IV disease was found in 12 (10.9%) patients. RESULTS: A total of 115 questionnaires were released, and five patients were excluded for too long evaluation time (n = 2) and the inability to confirm the questionnaire contents (n = 3). Finally, a total of 110 questionnaires were collected. They were aged 31-79 years, with the 40-59 age group being most represented (65.4% of all cases). Most patients were married (91.8%) and an overwhelming number had no religion (92.7%). Total SPB score was 43.13 ± 16.65. SPB was associated with the place of residence, monthly family income, payment method, transfer status, the presence of radiotherapy complications, and the presence of pain (P < 0.05). The SPB and self-care self-efficacy were negatively correlated (P < 0.01). In multivariate analysis, self-care self-efficacy, place of residence, monthly family income, payment method, degree of radiation dermatitis, and radiation proctitis were influencing factors of SPB (P < 0.05). CONCLUSION: Patients with cervical cancer undergoing radiotherapy often have SPB. Self-care self-efficacy scale, place of residence, monthly family income, payment method, and radiation dermatitis and proctitis are factors independently influencing SPB.

3.
World J Clin Cases ; 8(18): 4059-4066, 2020 Sep 26.
Artículo en Inglés | MEDLINE | ID: mdl-33024763

RESUMEN

BACKGROUND: Lung cancer is a clinical disease with multiple malignant tumors. Currently, it is difficult for patients to benefit from routine clinical nursing due to the lack of a pertinent and systematic approach. AIM: To investigate the effect of integrated nursing care on the negative emotions and satisfaction of lung cancer patients. METHODS: From January 2018 to December 2019, 92 patients with lung cancer were selected and divided into the study group and the control group; there were 46 patients in each group. The control group received routine nursing, and the study group received integrated medical care in addition to the care received by the control group. Negative emotions before and after the intervention, the self-management ability score after the intervention, family care burden after the intervention and nursing satisfaction after the intervention were measured in the two groups. RESULTS: After the intervention, the self-rating anxiety scale and self-rating depression scale scores in the study group were lower than those in the control group (P < 0.05); the scores for health knowledge, self-concept, self-responsibility and self-care skills in the study group were higher than those in the control group (P < 0.05); the scores for individual burden and responsibility burden in the study group were lower than those before the intervention (P < 0.05); and the nursing satisfaction in the study group (93.48%) was higher than that in the control group (78.26%, P < 0.05). CONCLUSION: An integrated nursing care approach for lung cancer patients can effectively relieve the patient's negative feelings, improve their self-management ability, help to reduce the burden of family care and improve patient satisfaction with nursing activities.

4.
Viruses ; 12(10)2020 10 09.
Artículo en Inglés | MEDLINE | ID: mdl-33050303

RESUMEN

The integrins function as the primary receptor molecules for the pathogenic infection of foot-and-mouth disease virus (FMDV) in vivo, while the acquisition of a high affinity for heparan sulfate (HS) of some FMDV variants could be privileged to facilitate viral infection and expanded cell tropism in vitro. Here, we noted that a BHK-adapted Cathay topotype derivative (O/HN/CHA/93tc) but not its genetically engineered virus (rHN), was able to infect HS-positive CHO-K1 cells and mutant pgsD-677 cells. There were one or three residue changes in the capsid proteins of O/HN/CHA/93tc and rHN, as compared with that of their tissue-originated isolate (O/HN/CHA/93wt). The phenotypic properties of a set of site-directed mutants of rHN revealed that E83K of VP1 surrounding the fivefold symmetry axis was necessary for the integrin-independent infection of O/HN/CHA/93tc. L80 in VP2 was essential for the occurrence of E83K in VP1 during the adaptation of O/HN/CHA/93wt to BHK-21 cells. L80M in VP2 and D138G in VP1 of rHN was deleterious, which could be compensated by K83R of VP1 for restoring an efficient infection of integrin-negative CHO cell lines. These might have important implications for understanding the molecular and evolutionary mechanisms of the recognition and binding of FMDV with alternative cellular receptors.


Asunto(s)
Sitios de Unión/fisiología , Proteínas de la Cápside/genética , Proteínas de la Cápside/metabolismo , Virus de la Fiebre Aftosa/metabolismo , Receptores Virales/metabolismo , Acoplamiento Viral , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Células CHO , Línea Celular , Cricetinae , Cricetulus , Fiebre Aftosa/virología , Virus de la Fiebre Aftosa/genética , Genoma Viral/genética , Heparitina Sulfato/metabolismo , Ratones , Receptores Virales/genética , Internalización del Virus
5.
Int J Oncol ; 55(1): 21-34, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31180559

RESUMEN

Emerging studies have indicated that leucine­rich repeat kinase 2 (LRRK2) is associated with thyroid cancer (TC). The present study investigated the effect of LRRK2 on the cell cycle and apoptosis in TC, and examined the underlying mechanisms in vitro. To screen TC­associated differentially expressed genes, gene expression microarray analysis was conducted. Retrieval of pathways associated with TC from the Kyoto Encyclopedia of Genes and Genomes database indicated that the c­Jun N­terminal kinase (JNK) signaling pathway serves an essential role in TC. SW579, IHH­4, TFC­133, TPC­1 and Nthy­ori3­1 cell lines were used to screen cell lines with the highest and lowest LRRK2 expression for subsequent experiments. The two selected cell lines were transfected with pcDNA­LRRK2, or small interfering RNA against LRRK2 or SP600125 (a JNK inhibitor). Subsequently, flow cytometry, terminal deoxynucleotidyl transferase­mediated dUTP­biotin nick end labeling, a 5­ethynyl­2'­deoxyuridine assay and a scratch test was conducted to detect the cell cycle distribution, apoptosis, proliferation and migration, respectively, in each group. The LRRK2 gene was determined to be elevated in TC based on the microarray data of the GSE3678 dataset. The SW579 cell line was identified to exhibit the highest LRRK2 expression, while IHH­4 cells exhibited the lowest LRRK2 expression. LRRK2 silencing, through inhibiting the activation of the JNK signaling pathway, increased the expression levels of genes and proteins associated with cell cycle arrest and apoptosis in TC cells, promoted cell cycle arrest and apoptosis, and inhibited cell migration and proliferation in TC cells, indicating that LRRK2 repression could exert beneficial effects through the JNK signaling pathway on TC cells. These observations demonstrate that LRRK2 silencing promotes TC cell growth inhibition, and facilitates apoptosis and cell cycle arrest. The JNK signaling pathway may serve a crucial role in mediating the anti­carcinogenic activities of downregulated LRRK2 in TC.


Asunto(s)
Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/biosíntesis , Proteína 2 Quinasa Serina-Treonina Rica en Repeticiones de Leucina/genética , Sistema de Señalización de MAP Quinasas , Neoplasias de la Tiroides/enzimología , Neoplasias de la Tiroides/genética , Antracenos/farmacología , Apoptosis/fisiología , Puntos de Control del Ciclo Celular/fisiología , Línea Celular Tumoral , Movimiento Celular/fisiología , Proliferación Celular/fisiología , Regulación hacia Abajo , Activación Enzimática , Humanos , MAP Quinasa Quinasa 4/antagonistas & inhibidores , MAP Quinasa Quinasa 4/metabolismo , Neoplasias de la Tiroides/patología , Transfección
6.
J Cell Biochem ; 120(2): 2159-2170, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30324763

RESUMEN

Despite the administration of exogenous insulin and other medications used to control many aspects of diabetes mellitus (DM), increased oxidative stress has been increasingly acknowledged in DM development and complications. Therefore, this study aims to investigate the role of advanced glycation end-products (AGEs) in oxidative stress (OS) of thyroid cells in patients with DM. Patients with DM with or without thyroid dysfunction (TD) were enrolled. Thyroid toxic damage was induced by adding AGE-modified bovine serum albumin (AGE-BSA) to normal human thyroid follicular epithelial cells. The cell viability, cell cycle, and cell apoptosis, as well as the content of reactive oxygen species (ROS), catalase (CAT), and malondialdehyde (MDA) in cells were measured. Thyroid hormones, T3, T4, FT3, and FT4 levels were measured by enzyme-linked immunosorbent assay. Receptor for advanced glycation end products (RAGE), sirtuin1 ( Sirt1), and NF-E2-related factor 2 ( Nrf2) expressions were detected, and the mitochondrial membrane potential was measured. We found increased AGEs in the serum of DM patients with TD. By increasing AGE-BSA concentration, cell viability; the thyroid hormones T3, T4, FT3, and FT4 levels; and mitochondrial membrane potential all significantly decreased. However, the increase in AGE-BSA concentration led to an increase in cell apoptosis, RAGE, and nuclear factor-κB expressions but produced the opposite effect on Sirt1, Nrf2, and heme oxygenase-1 expressions, as well as a decrease in antioxidant response element protein levels. The AGE-BSA increased ROS and MDA levels and reduced CAT level in normal human thyroid follicular epithelial cells on a dose independence basis. Our results demonstrated that AGEs-mediated direct increase of RAGE produced OS in thyroid cells of DM by inactivating the Sirt1/Nrf2 axis.

7.
J Cell Biochem ; 120(3): 4582-4598, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30320918

RESUMEN

Advanced glycation end products (AGEs) play a causative role in the complications involved with diabetes mellitus (DM). Nowadays, DM with hypothyroidism (DM-hypothyroidism) is indicative of an ascended tendency in the combined morbidity. In this study, we examine the role of the receptor (RAGE) played for AGEs in thyroid hormone (TH) secretion via the silent information regulator 1 (SIRT1)/nuclear factor erythroid-derived factor 2-related factor 2 (Nrf2) pathway. Blood samples were collected from patients with type 2 DM (T2DM)-hypothyroidism and from patients with T2DM, followed by detection of serum AGEs level. The underlying regulatory mechanisms of RAGE were analyzed in association with the treatment of high glucose, siRNA against RAGE, AGE, SIRT1, or Nrf2 vector in normal immortalized thyroid Nthy-ori 3-1 cells. Serum of patients with T2DM-hypothyroidism indicated promoted levels of AGEs vs those with just T2DM. Both AGEs and high glucose triggered cellular damage, increased oxidative stress, as well as displayed a decreased survival rate along with TH secretion in the Nthy-ori 3-1 cells. Moreover, AGEs and high glucose also led to RAGE upregulation, both SIRT1 and NRF2 downregulation, and the decreased expression of TH secretion-related proteins in Nthy-ori 3-1 cells. Notably, these alternations induced by the AGEs can be reserved by silencing RAGE or upregulating either SIRT1 or Nrf2, indicating a mechanism of regulating TH secretion through the SIRT1/Nrf2 pathway. Collectively, our data proposed that AGEs and high glucose exerted a potent effect on cellular damage and TH deficiency in Nthy-ori 3-1 cells through the RAGE upregulation as well as SIRT1/Nrf2 pathway inactivation. This mechanism may underlie the occurrence of DM-hypothyroidism.


Asunto(s)
Complicaciones de la Diabetes/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Productos Finales de Glicación Avanzada/metabolismo , Hipotiroidismo/metabolismo , Factor 2 Relacionado con NF-E2/biosíntesis , Transducción de Señal , Sirtuina 1/biosíntesis , Hormonas Tiroideas/metabolismo , Adulto , Anciano , Línea Celular , Complicaciones de la Diabetes/patología , Diabetes Mellitus Tipo 2/patología , Femenino , Regulación de la Expresión Génica , Humanos , Hipotiroidismo/patología , Masculino , Persona de Mediana Edad
8.
Mol Cells ; 41(9): 853-867, 2018 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-30165731

RESUMEN

As the most common type of endocrine malignancy, papillary thyroid cancer (PTC) accounts for 85-90% of all thyroid cancers. In this study, we presented the hypothesis that SDC4 gene silencing could effectively attenuate epithelial mesenchymal transition (EMT), and promote cell apoptosis via the Wnt/ß-catenin signaling pathway in human PTC cells. Bioinformatics methods were employed to screen the determined differential expression levels of SDC4 in PTC and adjacent normal samples. PTC tissues and adjacent normal tissues were prepared and their respective levels of SDC4 protein positive expression, in addition to the mRNA and protein levels of SDC4, Wnt/ß-catenin signaling pathway, EMT and apoptosis related genes were all detected accordingly. Flow cytometry was applied in order to detect cell cycle entry and apoptosis. Finally, analyses of PTC migration and invasion abilities were assessed by using a Transwell assay and scratch test. In PTC tissues, activated Wnt/ß-catenin signaling pathway, increased EMT and repressed cell apoptosis were determined. Moreover, the PTC K1 and TPC-1 cell lines exhibiting the highest SDC4 expression were selected for further experiments. In vitro experiments revealed that SDC4 gene silencing could suppress cell migration, invasion and EMT, while acting to promote the apoptosis of PTC cells by inhibiting the activation of the Wnt/ß-catenin signaling pathway. Besides, si-ß-catenin was observed to inhibit the promotion of PTC cell migration and invasion caused by SDC4 overexpression. Our study revealed that SDC4 gene silencing represses EMT, and enhances cell apoptosis by suppressing the activation of the Wnt/ß-catenin signaling pathway in human PTC.


Asunto(s)
Apoptosis/genética , Transición Epitelial-Mesenquimal/genética , Sindecano-4/metabolismo , Cáncer Papilar Tiroideo/patología , Neoplasias de la Tiroides/patología , Vía de Señalización Wnt/genética , Adulto , Anciano , Línea Celular Tumoral , Movimiento Celular/genética , Silenciador del Gen , Humanos , Persona de Mediana Edad , Invasividad Neoplásica/genética , Sindecano-4/genética , Cáncer Papilar Tiroideo/genética , Neoplasias de la Tiroides/genética
9.
J Cell Physiol ; 233(9): 7092-7102, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29633272

RESUMEN

This study is supposed to investigate the effect of FGF-23 on parathyroid hormone (PTH) secretion through ERK/MAPK signaling pathway in secondary hyperparathyroidism (SHPT) rat model. Thirty rats were equally served as the normal and SHPT groups. After transfection, parathyroid cells was assigned into blank, NC, pcDNA3.1-FGF-23, siRNA-FGF-23, U0126, and siRNA-FGF-23 + U0126 groups. The serum levels of Calcium (Ca), Phosphorus (P), alkaline phosphatase (ALP), and PTH were detected. HE and immunohistochemical (IHC) staining were used for the histopathological changes and the FGF-23, EKR1/2, and pEKR1/2 expressions. qRT-PCR and Western blotting were performed to determine the mRNA and protein expression of FGF-23, PTH, MAPK, EKR1/2, and Klotho. The proliferation, apoptosis, and cell cycle were all measured for parathyroid cells by CCK-8 assay, TUNEL staining and Flow cytometry. Compared with the normal group, the SHPT group showed increased serum levels PTH, P, ALP, and FGF-23 and mRNA and protein expressions of FGF-23 and PTH, whereas declined Ca and p-ERK1/2 expression, mRNA and protein expression of Klotho, cell apoptosis rate was reduced. Furthermore, compared to the blank and NC groups, the pcDNA3.1-FGF-23 and U0126 groups had a decreased mRNA expression of Klotho, protein expression of EKR1/2 and Klotho, and cell apoptosis rate was down-regulated, whereas the RNA and protein expressions of FGF-23 and PTH were up-regulated, and cell proliferation was elevated. The opposite results were observed in the siRNA-FGF-23 group. Our study demonstrated that FGF-23 could inhibit signaling transduction of ERK/MAPK pathway and accelerate the secretion of PTH in rats with SHPT.


Asunto(s)
Factores de Crecimiento de Fibroblastos/metabolismo , Hiperparatiroidismo Secundario/enzimología , Hiperparatiroidismo Secundario/patología , Sistema de Señalización de MAP Quinasas , Glándulas Paratiroides/enzimología , Glándulas Paratiroides/patología , Hormona Paratiroidea/metabolismo , Fosfatasa Alcalina/sangre , Animales , Apoptosis , Calcio/sangre , Ciclo Celular , Proliferación Celular , Creatinina/sangre , Modelos Animales de Enfermedad , Factor-23 de Crecimiento de Fibroblastos , Factores de Crecimiento de Fibroblastos/sangre , Factores de Crecimiento de Fibroblastos/genética , Glucuronidasa/sangre , Glucuronidasa/genética , Hiperparatiroidismo Secundario/sangre , Proteínas Klotho , Masculino , Hormona Paratiroidea/sangre , Fósforo/sangre , ARN Mensajero/genética , ARN Mensajero/metabolismo , Ratas Sprague-Dawley
10.
Int J Ophthalmol ; 10(1): 1-5, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28149769

RESUMEN

AIM: To identify the disease-causing mutation responsible for the presence of congenital cataract in a Chinese family. METHODS: The study recruited a four-generation Chinese pedigree affected by autosomal dominant congenital cataract (ADCC). Family history and the history of cataract extraction were recorded. Blood samples were collected from individuals for DNA extraction. Direct sequencing of congenital cataract-associated genes was performed. Single-strand conformational polymorphism and bioinformatic analysis were conducted to further study the mutation. RESULTS: Direct sequencing revealed a novel splice site mutation of c.30-2 A>G in the CRYBA3/A1 gene. The mutation co-segregated within all affected individuals in the family and was not found in unaffected members or 100 unrelated normal controls. These results were further confirmed by single-strand conformational polymorphism and bioinformatic analysis using the Human Splicing Finder and MaxEnt online software and Annovar computer software. CONCLUSION: c.30-2 A>G mutation of CRYBA3/A1 gene is a novel mutation and broadens the genetic spectrum of ADCC.

11.
BMC Med Genet ; 16: 11, 2015 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-25928629

RESUMEN

BACKGROUND: Polymorphisms of the CC chemokine receptor 6 (CCR6) and RNASET2 tag SNP have been shown to be associated with the susceptibility to several immune-related diseases. This study was conducted to identify the association of CCR6 and RNASET2 tag SNP with autoimmune thyroid diseases (AITDs) in the Chinese Han population. METHODS: We enrolled 1061 patients with AITDs, including 701 patients with Graves' disease (GD) and 360 patients with Hashimoto's thyroiditis (HT), and 938 healthy individuals for a case-control genetic association study. Three CCR6 single nucleotides polymorphisms (SNPs) (rs3093023/rs3093024/rs6902119) and one tagging SNP (rs9355610) within RNASET2 gene were selected for genotyping by multiplex polymerase chain reaction (PCR) and ligase detection reaction (LDR). RESULTS: The frequency of rs9355610 genotypes in the patients with GD differed significantly from that in the controls (p = 0.017). The frequency of the minor G allele of rs9355610 was significantly higher in the GD patients than in the healthy controls (p = 0.005, OR = 1.225, 95% CI:1.063-1.412). However, we could not find significant differences in the genotype or allele frequencies of HT patients compared with healthy controls. After gender stratification, the frequency of the minor G allele in both male and female GD patients was significantly higher than that in the healthy controls (p = 0.036, OR = 1.308, 95% CI:1.017-1.684 ; p = 0.048, OR = 1.19, 95% CI:1.001-1.413; respectively);. Furthermore, the frequency of haplotype AT in GD patients was significantly lower than that in their control groups (p = 0.003) and showed a protective effect against GD (OR = 0.806, 95% CI: 0.699-0.929). The frequency of haplotype GT in GD patients was significantly higher than that in their control groups (p = 0.048), indicating that GT was the risk haplotype to GD (OR = 1.267, 95% CI: 1.001-1.603). There were no significant differences in the allele or genotype frequencies of three SNPs of CCR6 (rs3093023/rs3093024/ rs6902119) gene between GD patients, HT patients and controls. CONCLUSIONS: Our results suggest that the rs9355610 tag SNP of RNASET2 gene is positively associated with susceptibility to GD in the Chinese Han population. No association was found for the tested CCR6 SNPs.


Asunto(s)
Pueblo Asiatico/etnología , Etnicidad/genética , Enfermedad de Graves/genética , Enfermedad de Hashimoto/genética , Polimorfismo de Nucleótido Simple , Receptores CCR6/genética , Ribonucleasas/genética , Proteínas Supresoras de Tumor/genética , Adulto , Pueblo Asiatico/genética , Femenino , Predisposición Genética a la Enfermedad/genética , Haplotipos/genética , Humanos , Masculino , Fenotipo
12.
Traffic ; 3(10): 730-9, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12230471

RESUMEN

We have analyzed the mechanism by which Sop4, a novel ER membrane protein, regulates quality control and intracellular transport of Pma1-7, a mutant plasma membrane ATPase. At the restrictive temperature, newly synthesized Pma1-7 is targeted for vacuolar degradation instead of being correctly delivered to the cell surface. Loss of Sop4 at least partially corrects vacuolar mislocalization, allowing Pma1-7 routing to the plasma membrane. Ste2-3 is a mutant pheromone receptor which, like Pma1-7, is defective in targeting to the cell surface, resulting in a mating defect. sop4delta suppresses the mating defect of ste2-3 cells as well as the growth defect of pma1-7. Visualization of newly synthesized Pma1-7 in sop4delta cells by indirect immunofluorescence reveals delayed export from the ER. Similarly, ER export of wild-type Pma1 is delayed in the absence of Sop4 although intracellular transport of Gas1 and CPY is unaffected. These observations suggest a model in which a selective increase in ER residence time for Pma1-7 may allow it to achieve a more favorable conformation for subsequent delivery to the plasma membrane. In support of this model, newly synthesized Pma1-7 is also routed to the plasma membrane upon release from a general block of ER-to-Golgi transport in sec13-1 cells.


Asunto(s)
Retículo Endoplásmico/metabolismo , Proteínas Fúngicas/metabolismo , ATPasas de Translocación de Protón/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Secuencia de Bases , Cartilla de ADN , Proteínas Fúngicas/genética , Genes Supresores , Transporte de Proteínas
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