{"symbol":"CR1","synonyms":["KN","C4BR","C3BR","CD35"],"name":"complement component (3b/4b) receptor 1 (Knops blood group)","description":"This gene is a member of the receptors of complement activation (RCA) family and is located in the \u0027cluster RCA\u0027 region of chromosome 1. The genome is polymorphic at this locus with allele-specific splice variants encoding different isoforms, based on the presence/absence of long homologous repeats (LHRs). The gene encodes a monomeric single-pass type I membrane glycoprotein found on erythrocytes, leukocytes, glomerular podocytes, and splenic follicular dendritic cells. The Knops blood group system is a system of antigens located on this protein. The protein mediates cellular binding to particles and immune complexes that have activated complement. Decreases in expression of this protein and/or mutations in this gene have been associated with gallbladder carcinomas, mesangiocapillary glomerulonephritis, systemic lupus erythematosus, sarcoidosis and Alzheimer\u0027s disease. Mutations in this gene have also been associated with a reduction in Plasmodium falciparum rosetting, conferring protection against severe malaria. [provided by RefSeq, May 2020]","ncbiEntrezGeneId":1378,"ncbiEntrezGeneUrl":"http://www.ncbi.nlm.nih.gov/gene/1378","proteins":[{"symbol":"CR1_HUMAN","href":"/api/1.0/protein/CR1_HUMAN"}],"hgncRootFamilies":[{"name":"Blood group antigens","href":"/api/1.0/gene_family/Blood+group+antigens"},{"name":"Complement system","href":"/api/1.0/gene_family/Complement+system"},{"name":"CD molecules (CD)","href":"/api/1.0/gene_family/CD+molecules+%28CD%29"}]}