Complement Factor H Related 5

Complement factor H-related protein 5 (CFHR5) is a nine-domain FHR family protein that binds C3b and C3d, heparin, and pentraxins, and is produced notably in the kidney as well as in liver. By interacting with deposited C3 fragments and glomerular basement-membrane ligands, CFHR5 modulates alternative-pathway activity on renal surfaces, and gain-of-function or hybrid CFHR5-factor H proteins cause C3 glomerulopathy, including a form endemic to Cyprus. It also associates with meningococcal surfaces. Recombinant CFHR5 is used to dissect glomerular complement regulation, C3b binding, and the pathogenesis of CFHR5 nephropathy. Like other FHR proteins, CFHR5 can form homo- and heterodimers within the family.