Fc Receptor Like Protein 2 (FCRL2)

FCRL2 encodes a member of the immunoglobulin receptor superfamily and is one of several Fc receptor-like glycoproteins clustered on the long arm of chromosome 1. The encoded protein has four extracellular C2-type immunoglobulin domains, a transmembrane domain and a cytoplasmic domain that contains one immunoreceptor-tyrosine activation motif and two immunoreceptor-tyrosine inhibitory motifs.The deduced 255-amino acid transmembrane protein contains 2 ITIMs. Further searches and sequencing identified a 192-amino acid splice variant, SPAP1B, lacking the intracellular ITIMs, and a 144-amino acid isoform, SPAP1C, lacking the transmembrane segment. This protein may be a prognostic marker for chronic lymphocytic leukemia.