MS4A1
This gene encodes a member of the membrane-spanning 4A gene family. Members of this nascent protein family are characterized by common structural features and similar intron/exon splice boundaries and display unique expression patterns among hematopoietic cells and nonlymphoid tissues. This gene encodes a B-lymphocyte surface molecule which plays a role in the development and differentiation of B-cells into plasma cells. This family member is localized to 11q12, among a cluster of family members. Alternative splicing of this gene results in two transcript variants which encode the same protein.
Full Name
Membrane Spanning 4-Domains A1
Alternative Names
Membrane Spanning 4-Domains A1; Membrane-Spanning 4-Domains, Subfamily A, Member 1; Leukocyte Surface Antigen Leu-16; CD20 Antigen; CD20; Bp35; Membrane-Spanning 4-Domains Subfamily A Member 1; B-Lymphocyte Cell-Surface Antigen B1; B-Lymphocyte Surface Antigen B1;
Function
B-lymphocyte-specific membrane protein that plays a role in the regulation of cellular calcium influx necessary for the development, differentiation, and activation of B-lymphocytes (PubMed:3925015, PubMed:7684739, PubMed:12920111).
Functions as a store-operated calcium (SOC) channel component promoting calcium influx after activation by the B-cell receptor/BCR (PubMed:7684739, PubMed:12920111, PubMed:18474602).
Biological Process
B cell activation Source: UniProtKB
B cell differentiation Source: UniProtKB
B cell proliferation Source: UniProtKB
B cell receptor signaling pathway Source: UniProtKB
Calcium ion import into cytosol Source: UniProtKB
Cell surface receptor signaling pathway Source: GO_Central
Humoral immune response Source: UniProtKB
Protein tetramerization Source: UniProtKB
Response to bacterium Source: Ensembl
Store-operated calcium entry Source: UniProtKB
Cellular Location
Plasma membrane
Cell membrane
Note: Constitutively associated with membrane rafts.
Involvement in disease
Immunodeficiency, common variable, 5 (CVID5):
A primary immunodeficiency characterized by antibody deficiency, hypogammaglobulinemia, recurrent bacterial infections and an inability to mount an antibody response to antigen. The defect results from a failure of B-cell differentiation and impaired secretion of immunoglobulins; the numbers of circulating B-cells is usually in the normal range, but can be low.
Topology
Cytoplasmic: 1-56
Helical: 57-78
Extracellular: 79-84
Helical: 85-105
Cytoplasmic: 106-120
Helical: 121-141
Extracellular: 142-188
Helical: 189-209
Cytoplasmic: 210-297
PTM
Phosphorylated on serines and threonines in resting B-cells. Protein kinase C/PKC can use CD20 as substrate.