title: Human C3 glomerulopathy provides unique insights into complement factor H-related protein function.
abstract: The study in this issue of the JCI by Tortajada et al. demonstrates that a duplication within the gene complement factor H–related 1 (CFHR1; encoding FHR1) leads to the production of an aberrant larger form of the protein. Elegant in vitro studies of the mutant and normal variants demonstrate an unexpected mechanism of action of FHR1, wherein homodimeration and hetero- oligomerization with FHR2 and FHR5 generates more avid molecules that very effectively compete with FH binding to surfaces and impair its ability to regulate local complement activation. As variants of FHRs are linked to many human inflammatory and autoimmune diseases, these and other recently published structure/function studies of these proteins provide key insights into their complement regulatory activities and likely roles in disease.
authors.affiliation: Department of Medicine, Division of Rheumatology, University of Colorado School of Medicine, Aurora, Colorado 80045, USA. michael.holers@ucdenver.edu
authors.forename: V Michael
authors.initials: VM
authors.lastname: Holers
mesh_terms: D003176:Complement C3 / Q000378:metabolism*; D003180:Complement C3b Inactivator Proteins / Q000235:genetics*; D005260:Female; D006801:Humans; D007674:Kidney Diseases / Q000235:genetics*; D008297:Male
chemical_list: C517621:CFHR1 protein, human; D003176:Complement C3; D003180:Complement C3b Inactivator Proteins