an integral membrane protein that associates with surface immunoglobulin B lymphocyte antigen receptor multimeric complex. Surface Ig non-covalently associates with 2 other proteins, Ig-alpha and Ig-beta, which are necessary for expression and function of the B-cell antigen receptor. Two alternatively spliced isoforms have been described. Note: This description may include information from UniProtKB.
Protein type: Immunoglobulin superfamily; Membrane protein, integral