Anti-Polycystin-1 Antibody, clone E4 (5F4D2) clone E4 (5F4D2), from mouse

Polycystin-1 (UniProt P98161; also known as Autosomal dominant polycystic kidney disease 1 protein) is encoded by the PKD1 gene (Gene ID 5310) in human. The primary cilium is a microtubule-based mechano- and chemo-sensory organelle that coordinates an array of cellular pathways during development and in tissue homeostasis, including Hedgehog (Hh), PDGFRalpha and Wnt signaling. Defective ciliary function causes a variety of ciliopathies, including autosomal dominant polycystic kidney disease (ADPKD). Polycystin-1 (PC1) and polycystin-2 (PC2) are large transmembrane proteins co-localized to primary cilium, where they play an important role in calcium-based signalling. PC1 is an atypical adhesion G-protein-coupled receptor (aGPCR) with 11-transmemrbane domains. PC1 is cis-autoproteolytically cleaved at a juxtamembrane GPCR cleavage site (GPS; a.a. 3012-3061) in a developmental stage-dependent manner, where PC1 is largely uncleaved in early embryonic kidneys but becomes extensively cleaved after birth. GPS cleavage results in a heterodimeric PC1 form, in which the N-terminal fragment (NTF) remains non-covalently associated with the transmembrane C-terminal fragment (CTF). Transgenic mice expressing non-cleavable PC1 develop cystic kidney disease during the postnatal period.