scholarly journals The isolated polycystin-1 cytoplasmic COOH terminus prolongs ATP-stimulated Cl– conductance through increased Ca2+ entry

2003 ◽  
Vol 285 (6) ◽  
pp. F1168-F1178 ◽  
Author(s):  
Scott S. Wildman ◽  
Kimberly M. Hooper ◽  
Clare M. Turner ◽  
James S. K. Sham ◽  
Edward G. Lakatta ◽  
...  

The precise steps leading from mutation of the polycystic kidney disease ( PKD1) gene to the autosomal dominant polycystic kidney disease (ADPKD) phenotype remain to be established. Fluid accumulation is a requirement for cyst expansion in ADPKD, suggesting that abnormal fluid secretion into the cyst lumen might play a role in disease. In this study, we sought to establish a link between polycystin-1 (the PKD1 gene product) and ATP-stimulated Cl– secretion in renal tubule cells. To do this, we performed a whole cell patch-clamp analysis of the effects of expression of the isolated cytoplasmic COOH-terminus of polycystin-1 in stably transfected mouse cortical collecting duct cells. The truncated polycystin-1 fusion protein prolonged the duration of ATP-stimulated Cl– conductance and intracellular Ca2+ responses. Both effects were dependent on extracellular Ca2+. It was determined that expression of the truncated polycystin-1 fusion protein introduced, or activated, an ATP-induced Ca2+ entry pathway that was undetectable in transfection control cell lines. Our findings are concordant with increasing evidence for a role of polycystin-1 in cell Ca2+ homeostasis and indicate that dysregulated Ca2+ entry might promote Cl– secretion and cyst expansion in ADPKD.

Gene ◽  
2018 ◽  
Vol 671 ◽  
pp. 28-35 ◽  
Author(s):  
Mayssa Abdelwahed ◽  
Pascale Hilbert ◽  
Asma Ahmed ◽  
Hichem Mahfoudh ◽  
Salem Bouomrani ◽  
...  

Author(s):  
Н.Н. Вассерман ◽  
А.В. Поляков

Поликистозная болезнь почек (ПП) является клинически и генетически гетерогенной группой заболеваний, может наследоваться как аутосомно-доминантно (АД), так и аутосомно-рецессивно (АР). К развитию АР ПП приводят мутации в гене PKHD1. Большинство мутаций при АД ПП находят в гене PKD1 (80-85%). Примерно в 15% случаев мутации выявляют в гене PKD2. Клиническое и генетическое разнообразие ПП требует поиска мутаций в нескольких генах, поэтому он является трудоемким, дорогостоящим и требует много времени. Метод массового параллельного секвенирования (МПС) позволяет проводить поиск мутаций в нескольких генах одновременно независимо от их размера. Проведен поиск мутаций в 254 семьях с ПП методом МПС с использованием панели, включающей гены PKHD1, PKD1, PKD2, HNF1B и GANAB. Два варианта в гене PKHD1 было идентифицировано в 49 семьях (19%), один вариант найден в 9 случаях (3,5%); в гене PKD1 обнаружено 62 варианта (24,5%), в гене PKD2 - 6 вариантов (2,5%), в гене HNF1B - 9 вариантов (3,5%). В 119 семьях, что составило 47%, мутации найдены не были. У больных из семей с генеалогически установленным АД типом наследования в большинстве случаев (39 из 66; 59%) выявлены варианты в гене PKD1, приводящие к ПП. Из 59 изолированных случаев ПП в 17% (10 человек) идентифицированы 2 варианта в гене PНKD1, в 20% (12 человек) - в гене PKD1. При неизвестном типе наследования (129 случаев) в 29,5% (38 чел.) найдены 2 варианта в гене PНKD1, в 8,5% (11 чел.) - в гене PKD1, в 3% (4 чел.) - в гене PKD2, в 4% (5 чел.) - в гене HNF1B. Таким образом, МПС относительно быстро позволяет проводить молекулярно-генетический анализ одновременно в нескольких генах у больных с признаками ПП. Polycystic kidney disease is a heterogeneous group of autosomal dominant or autosomal recessive disorders with age of manifestation varying from prenatal period to adulthood. Autosomal recessive polycystic kidney disease is caused by mutations in the PKHD1 gene. Approximately 85% of all autosomal dominant polycystic kidney disease cases are caused by mutations in the PKD1 gene, and around 15% - by mutations in the PKD2 gene. All these genes are large, and mutations were found to be scattered throughout the genes without any clustering. Therefore, mutation detection requires a lot of time, money, and effort. Due to clinical and genetic diversity of polycystic kidney disease, the search for mutations has to be carried out in several genes. Mass parallel sequencing (MPS) allows to analyze several genes simultaneously regardless of their size. 254 families with polycystic kidney disease were examined using mass parallel sequencing with a gene panel that included PKHD1, PKD1, PKD2, HNF1B and GANAB. Two variants in PKHD1 were found in 49 families (19%), one variant - in 9 families (3.5%); in PKD1 62 variants were detected (24.5%), in PKD2 - 6 variants (2.5%), in HNF1B - 9 variants (3.5%). In 119 families (47%) there were no mutations in the target genes. Among 66 patients from families with autosomal dominant polycystic kidney disease, 39 patients (59%) had mutations in the PKD1 gene. Out of 59 sporadic cases, 10 patients (17%) had 2 variants in PНKD1, 12 patients (20%) - in PKD1. 38 patients (29.5%) out of 129 patients with unknown type of inheritance had 2 variants in PНKD1, 11 patients (8.5%) - in PKD1, 4 patients (3%) - in PKD2, 5 patients (4%) - in HNF1B. Mass parallel sequencing allows to carry out relatively rapid molecular genetic analysis of several genes simultaneously for patients with symptoms of polycystic kidney disease.


2002 ◽  
Vol 17 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Lan Ding ◽  
Sizhong Zhang ◽  
Weimin Qiu ◽  
Cuiying Xiao ◽  
Shaoqing Wu ◽  
...  

Abstract Background. Autosomal dominant polycystic kidney disease (ADPKD) is a common disease in China. The major gene responsible for ADPKD, PKD1, has been fully characterized and shown to encode an integral membrane protein, polycystin 1, which is thought to be involved in cell–cell and cell–matrix interaction. Until now, 82 mutations of PKD1 gene have been reported in European, American, and Asian populations. However, there has been no report on mutations of the PKD1 gene in a Chinese population. Methods. Eighty Chinese patients in 60 families with ADPKD were screened for mutations in the 3′ region of the PKD1 gene using polymerase chain reaction–single-strand conformation polymorphism (PCR–SSCP) and DNA-sequencing techniques. Results. Three mutations were found. The first mutation is a 12593delA frameshift mutation in exon 45, and the polycystin change is 4129WfsX4197, 107 amino acids shorter than the normal polycystin (4302aa). The second mutation is a 12470InsA frameshift mutation in exon 45, producing 4088DfsX4156, and the predicted protein is 148 amino acids shorter than the normal. The third one is a 11151C→T transition in exon 37 converting Pro3648 to Leu. In addition, nine DNA variants, including IVS44delG, were identified. Conclusions. Three mutations in Chinese ADPKD patients are described and all of them are de novo mutations. Data obtained from mutation analysis also suggests that the mutation rate of the 3′ single-copy region of PKD1 in Chinese ADPKD patients is very low, and there are no mutation hot spots in the PKD1 gene. Mutations found in Chinese ADPKD patients, including nucleotide substitution and minor frameshift, are similar to the findings reported by other researchers. Many mutations of the PKD1 gene probably exist in the duplicated region, promoter region, and the introns of PKD1.


1997 ◽  
Vol 31 (3) ◽  
pp. 241-247 ◽  
Author(s):  
J. Nauta ◽  
M. A. Goedbloed ◽  
T. M. Luider ◽  
A. Th. Hoogeveen ◽  
A. M. W. van den Ouweland ◽  
...  

Human autosomal dominant polycystic kidney disease (ADPKD) is a high incidence disorder, leading to renal failure in many patients. The majority of cases results from a mutation in the PKD1 gene. The only well documented animal model of ADPKD is the Han:SPRD- Pkd strain. Its genetic basis is unknown as yet. In the current study we determined whether the disease in these rats is genetically linked to the rat homologue of the PKD1 gene. We used the protamine gene as a polymorphic marker ( Prm1) of the PKD1 region. Matings of Han:SPRD- Pkd with BB rats and backcross of the offspring with BB yielded animals informative for linkage analysis. This analysis revealed random segregation of the defect and the Prm1 marker, indicating that the model is not caused by a mutation in the PKD1 gene. We conclude that the Han:SPRD- Pkd rat strain is not a genetic model of PKD1.


2020 ◽  
Author(s):  
Chaozhe Yang ◽  
Amber K. O’Connor ◽  
Robert A. Kesterson ◽  
Jacob A. Watts ◽  
Amar J. Majmundar ◽  
...  

AbstractMutation of the Cys1 gene underlies the renal cystic disease in the Cys1cpk/cpk (cpk) mouse that phenocopies human autosomal recessive polycystic kidney disease (ARPKD). Cystin, the protein product of Cys1, is expressed in the primary apical cilia of renal ductal epithelial cells. In previous studies, we showed that cystin regulates Myc expression via interaction with the tumor suppressor, necdin. Here, we demonstrate rescue of the cpk renal phenotype by kidney-specific expression of a cystin-GFP fusion protein encoded by a transgene integrated into the Rosa26 locus. In addition, we show that expression of the cystin-GFP fusion protein in collecting duct cells down-regulates expression of Myc in cpk kidneys. Finally, we report the first human patient with an ARPKD phenotype due to homozygosity for a predicted deleterious splicing defect in CYS1. These findings suggest that mutations in the Cys1 mouse and CYS1 human orthologues cause an ARPKD phenotype that is driven by overexpression of the Myc proto-oncogene.Translational StatementThe cystin-deficient cpk mouse is a model for the study of autosomal recessive polycystic kidney disease (ARPKD). We show that the cpk mouse phenotype is associated with altered Myc expression. To date, the clinical relevance of cystin deficiency to human disease was unclear, due to the absence of ARPKD cases associated with CYS1 mutations. We report the first case of ARPKD linked to a CYS1 mutation disrupting normal splicing. These findings confirm the relevance of cystin deficiency to human ARPKD, implicate Myc in disease initiation or progression, and validate the cpk mouse as a translationally relevant disease model.


Author(s):  
J. M. Guerra ◽  
N. C. Cardoso ◽  
A. G. T. Daniel ◽  
L. F. Onuchic ◽  
B. Cogliati

Abstract Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic disease in cats. However, scarce data on its prevalence are available in Brazil. Persian cats and Persian-related breeds were assessed by molecular genotyping for a C to A transversion in exon 29 of PKD1 gene to determine ADPKD prevalence in a Brazilian population. Genomic DNA extracted from peripheral whole blood or oral swabs samples was used to amplify exon 29 of PKD1 gene employing a PCR-RFLP methodology. From a total of 616 animals, 27/537 Persian and 1/17 Himalayan cats showed the single-nucleotide variant (C to A) at position 3284 in exon 29 of feline PKD1. This pathogenic variation has been identified only in heterozygous state. The prevalence of ADPKD in Persian cats and Persian-related breeds was 5.03% and 1.6%, respectively. There was no significant association between feline breed, gender or age with ADPKD prevalence. Of note, the observed ADPKD prevalence in Persian cats and Persian-related breeds in Brazil was lower than the ones reported in other parts of the world. This finding may be related to genetic counseling and consequent selection of ADPKD-free cats for reproduction.


Sign in / Sign up

Export Citation Format

Share Document