Fc Receptor Like Protein B (FCRLB)

FCRLB has a hydrophobic leader peptide, 3 Ig-like domains, and a C-terminal domain enriched in proline, serine, and threonine. FCRLB contains a conserved motif consisting of charged amino acids interspersed with dileucine repeats that is predicted to adopt an alpha-helical structure. FCRL2 also has 2 potential N-glycosylation sites. Four additional FCRL2 splice variants could be separated into 2 groups that encode proteins that differ from each other and from full-length FCRL2 following the second Ig-like domain due to a frameshift. The 2 variants in each of these groups differ from one another in the presence or absence of exon 2, which encodes part of the leader peptide. Western blot analysis of transfected human embryonic kidney cells detected FCRL2 at an apparent molecular mass of 57 kD, indicating posttranslational modification.