polycystin1

Polycystin-1 (PC1) is a large, integral membrane protein encoded by the PKD1 gene in humans. It is primarily expressed in the epithelial cells of the kidney, liver, and pancreas. PC1 plays a crucial role in the regulation of cell growth, differentiation, and mechanosensation within renal tubular structures.

Structurally, polycystin-1 is characterized by multiple transmembrane domains, a large extracellular region containing numerous leucine-rich repeats, and a cytoplasmic C-terminal tail. The protein interacts with polycystin-2 (PC2), a calcium-permeable cation channel, forming a complex that is involved in calcium signaling and cellular mechanosensation.

Functionally, PC1 is believed to act as a receptor or sensor for mechanical stimuli, translating physical forces into cellular responses. Its role in maintaining renal tubule architecture and function is critical, and disruption of PC1 function has been associated with the development of autosomal dominant polycystic kidney disease (ADPKD), one of the most common genetic disorders leading to kidney failure.

Mutations in the PKD1 gene are responsible for approximately 85% of ADPKD cases. These mutations often result in loss of normal PC1 function, leading to abnormal cell proliferation and cyst formation. Research into PC1's structure and interactions continues to provide insights into the molecular mechanisms underlying cystogenesis and potential therapeutic targets for ADPKD.

Overall, polycystin-1 is a vital protein involved in renal health, cellular signaling, and mechanosensation, with its dysfunction contributing to significant human disease.