1. The PKD1 and PKD2 gene products are integral transmembrane proteins
The PKD1 and PKD2 gene products are integral transmembrane proteins. Polycystin-1 is predicted to have an extracellular N-terminus of ≈3000 amino acids, an odd number of transmembrane-spanning elements and a short cytoplasmic C-terminus that interacts with the C-terminus of polycystin-2. It has a lengthy list of domains (shown schematically in inset box) that have been found in proteins involved in mediating cell-cell or cell matrix interactions, suggesting a similar role for polycystin-1. Polycystin-2 has homology to the voltage-activated family of calcium channels with six transmembrane spans and an EF-hand that may bind calcium and serve to regulate the channel's activity. According to the current schema, ligand binding by the extracellular N-terminus of polycystin-1 is thought to regulate the channel activity of polycystin-2. (Modified from Watnick and Germino.201 Used with permission.)
Source: Autosomal Dominant Polycystic Kidney Disease, The Online Metabolic and Molecular Bases of Inherited Disease
Citation: Valle D, Beaudet AL, Vogelstein B, Kinzler KW, Antonarakis SE, Ballabio A, Gibson K, Mitchell G. The Online Metabolic and Molecular Bases of Inherited Disease; 2014 Available at: Accessed: October 20, 2017
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