Polycystin 1

Polycystin 1 (often abbreviated PC1) is a protein that in humans is encoded by the PKD1 gene (polycystin gene1). Mutations of PKD1 are associated with in a high percentage with cases of autosomal dominant polycystic kid ney disease, a severe inherited kidney disease characterized by the development of renal cysts and severe renal dysfunction (Hopp K et al. 2012). Numerous mutations in polycystin gene 1 have now been described (Wang H et al. 2020).

Polycystin-1 and polycystin-2 are expressed in primary cilia, as well as apical membranes, adherens junctions, and desmosomes, and participate in a variety of signaling pathways (Merrick D et al. 2014). Both proteins form a receptor-ion channel complex. The function of this complex, particularly the role of polycystin-1, has not been fully elucidated due to the lack of a reliable functional assay (Wang Z et al. 2019).

Polycystin1 has 11 transmembrane domains, a large extracellular N-terminal domain and a short (approximately 200 amino acids) cytoplasmic C-terminal domain. This intracellular domain contains a coiled-coil domain through which PC1 interacts with polycystin 2 (PC2), a membrane-bound Ca2+-permeable ion channel. PC1 is thought to function as a G protein-coupled receptor.

1. Hopp K et al (2012) Functional polycystin-1 dosage governs autosomal dominant polycystic kidney disease severity. J Clin Invest 122:4257-4273.
2. Merrick D et al (2014) Polycystin-1 cleavage and the regulation of transcriptional pathways. Pediatr Nephrol 29:505-511.
3. Wang Z et al (2019) the ion channel function of polycystin-1 in the polycystin-1/polycystin-2 complex. EMBO Rep 20:e48336.
4. Wang H et al (2020) Analysis of mutations in six Chinese families with autosomal dominant polycystic kidney disease. Am J Transl Res 12:8123-8136.