|Podocan in Mouse Kidney. Podocan was detected in perfusion fixed frozen sections of mouse kidney using 15 µg/mL Goat Anti-Mouse Podocan Antigen Affinity-purified Polyclonal Antibody (Catalog # AF3104) overnight at 4 °C. Tissue was stained with the Anti-Goat HRP-DAB Cell & Tissue Staining Kit (brown; Catalog # CTS008) and counterstained with hematoxylin (blue). Specific labeling was localized to vascular endothelial cells within glomeruli. View our protocol for Chromogenic IHC Staining of Frozen Tissue Sections.|
Mouse Podocan is a 95 kDa, secreted glycoprotein that is a class V member of the small leucine rich protein gene family (1, 2). It is synthesized as a 611 amino acid (aa) precursor that contains a 23 aa signal sequence, a cysteine-rich region, a series of leucine rich repeats (LRRs), and an extensive acidic C-terminal domain (4, 5). The 15 aa cysteine-rich region (aa 69-84) shows a CX3CXCX7C motif, qualifying it as a class V SLRP family member. This is followed by twenty LRRs, thirteen of which are type T (4xLeu; 1xPhe) and seven type S (4xLeu; 2xPro). The LRRs run uninterrupted from aa 89-559. The C-terminal seventeen amino acids contain fourteen Glu residues. The negative charge associated with these residues may play a role in basement membrane permeability (4). Mature mouse Podocan is 93% and 94% aa identical to human and canine Podocan, respectively. Over the last 504 aa, mouse Podocan shares 98% aa sequence identity with rat Podocan. Podocan is apparently secreted by podocytes and vascular endothelial cells, and deposited in the underlying basement membrane (4). Podocan is known to bind to type I collagen, and have an inhibitory effect on the migration of Podocan-transfected CHO cells (5). The significance of this is unclear.