[HTML][HTML] Nephritogenic mAb 5-1-6 is directed at the extracellular domain of rat nephrin

PS Topham, H Kawachi, SA Haydar… - The Journal of …, 1999 - Am Soc Clin Investig
PS Topham, H Kawachi, SA Haydar, S Chugh, TA Addona, KB Charron, LB Holzman…
The Journal of clinical investigation, 1999Am Soc Clin Investig
mAb 5-1-6 identifies an antigen on rat podocyte slit-diaphragms and induces severe
proteinuria when injected into rats. Nephrin, an Ig-like transmembrane protein that is
mutated in congenital nephrotic syndrome of the Finnish type, has been localized to the slit-
diaphragm on human podocytes. Here we document that the mAb 5-1-6 antigen is rat
nephrin. After incubation of rat glomeruli with this mAb, the antibody/antigen complex was
chemically cross-linked, extracted, and immunoprecipitated, prior to Western analysis. By …
mAb 5-1-6 identifies an antigen on rat podocyte slit-diaphragms and induces severe proteinuria when injected into rats. Nephrin, an Ig-like transmembrane protein that is mutated in congenital nephrotic syndrome of the Finnish type, has been localized to the slit-diaphragm on human podocytes. Here we document that the mAb 5-1-6 antigen is rat nephrin. After incubation of rat glomeruli with this mAb, the antibody/antigen complex was chemically cross-linked, extracted, and immunoprecipitated, prior to Western analysis. By mass spectrometry and 2D gel electrophoresis, we identified several peptides with complete identity to human nephrin. In addition, the 185-kDa protein immunoprecipitated by mAb 5-1-6 from rat glomerular extracts reacts with a rabbit anti-mouse nephrin antibody. Finally, nephrin and the mAb 5-1-6 antigen have identical glomerular localization patterns on immunofluorescence of rat kidney. These results demonstrate that the nephritogenic mAb 5-1-6 identifies the extracellular domain of nephrin, thereby documenting the importance of the slit-diaphragm and its component, nephrin, in the regulation of glomerular permselectivity.
J. Clin. Invest.104:1559–1566 (1999).
The Journal of Clinical Investigation