BLK

This gene encodes a nonreceptor tyrosine-kinase of the src family of proto-oncogenes that are typically involved in cell proliferation and differentiation. The protein has a role in B-cell receptor signaling and B-cell development. The protein also stimulates insulin synthesis and secretion in response to glucose and enhances the expression of several pancreatic beta-cell transcription factors. [provided by RefSeq, Aug 2010]

BLK Proto-Oncogene, Src Family Tyrosine Kinase

Non-receptor tyrosine kinase involved in B-lymphocyte development, differentiation and signaling (By similarity).
B-cell receptor (BCR) signaling requires a tight regulation of several protein tyrosine kinases and phosphatases, and associated coreceptors (By similarity).
Binding of antigen to the B-cell antigen receptor (BCR) triggers signaling that ultimately leads to B-cell activation (By similarity).
Signaling through BLK plays an important role in transmitting signals through surface immunoglobulins and supports the pro-B to pre-B transition, as well as the signaling for growth arrest and apoptosis downstream of B-cell receptor (By similarity).
Specifically binds and phosphorylates CD79A at 'Tyr-188'and 'Tyr-199', as well as CD79B at 'Tyr-196' and 'Tyr-207' (By similarity).
Phosphorylates also the immunoglobulin G receptors FCGR2A, FCGR2B and FCGR2C (PubMed:8756631).
With FYN and LYN, plays an essential role in pre-B-cell receptor (pre-BCR)-mediated NF-kappa-B activation (By similarity).
Contributes also to BTK activation by indirectly stimulating BTK intramolecular autophosphorylation (By similarity).
In pancreatic islets, acts as a modulator of beta-cells function through the up-regulation of PDX1 and NKX6-1 and consequent stimulation of insulin secretion in response to glucose (PubMed:19667185).
Phosphorylates CGAS, promoting retention of CGAS in the cytosol (PubMed:30356214).

B cell receptor signaling pathway Source: UniProtKB
Cell differentiation Source: GO_Central
Cellular response to DNA damage stimulus Source: GO_Central
Dendritic cell differentiation Source: GO_Central
Fc receptor mediated stimulatory signaling pathway Source: GO_Central
Innate immune response Source: GO_Central
Intracellular signal transduction Source: ProtInc
Negative regulation of B cell proliferation Source: GO_Central
Negative regulation of mast cell proliferation Source: GO_Central
Neuron projection development Source: GO_Central
Peptidyl-tyrosine phosphorylation Source: UniProtKB
Platelet degranulation Source: GO_Central
Positive regulation of dendritic cell apoptotic process Source: GO_Central
Positive regulation of insulin secretion Source: UniProtKB
Regulation of B cell apoptotic process Source: GO_Central
Regulation of B cell receptor signaling pathway Source: GO_Central
Regulation of mast cell degranulation Source: GO_Central
Regulation of platelet aggregation Source: GO_Central
Tolerance induction to self antigen Source: GO_Central
Transmembrane receptor protein tyrosine kinase signaling pathway Source: GO_Central

Cell membrane. Present and active in lipid rafts. Membrane location is required for the phosphorylation of CD79A and CD79B (By similarity).

Maturity-onset diabetes of the young 11 (MODY11): A form of diabetes that is characterized by an autosomal dominant mode of inheritance, onset in childhood or early adulthood (usually before 25 years of age), a primary defect in insulin secretion and frequent insulin-independence at the beginning of the disease.

Phosphorylated on tyrosine residues after antibody-mediated surface engagement of the B-cell antigen receptor (BCR).
Ubiquitination of activated BLK by the UBE3A ubiquitin protein ligase leads to its degradation by the ubiquitin-proteasome pathway.