8.A.21.1.2
Podocin of 383 aas and 1 TMS.  Expressed exclusively in the slit-diaphragm of podocytes.  Mutations lead to steroid resistance followed by renal disease (Mulukala et al. 2016). Podocytes are crucial cells of the glomerular filtration unit that play a vital role at the interface of the blood-urine barrier. Podocyte slit-diaphragm is a modified tight junction that facilitates size and charge-dependent permselectivity. Several proteins including podocin, nephrin (TC# 8.a.23.1.33), CD2AP (8.A.34.1.5), and TRPC6 (1.A.4.1.5) form a macromolecular assembly that constitutes the slit-diaphragm that resembles tight junctions. Podocin is an integral membrane protein attached to the inner membrane of the podocyte via a short transmembrane region (101-125). The cytosolic N- and C-termini help podocin attain a hook-like structure. The protein forms a homooligomer, a 16-mer (Mulukala et al. 2020).