BLNK

B-cell linker protein ;
B-cell adapter containing a SH2 domain protein ;
B-cell adapter containing a Src homology 2 domain protein ;
Cytoplasmic adapter protein ;
Src homology 2 domain-containing leukocyte protein of 65 kDa ;
SLP-65 ;

disease:Defects in BLNK are the cause of hypoglobulinemia and absent B-cells [MIM:604515]. This is a developmental blockage at the pro- to pre-B-cell transition. ,disease:In 6 of 34 childhood pre-B acute lymphoblastic leukemia (ALL) samples that were tested showed a complete loss or drastic reduction of BLNK expression. ,function:Functions as a central linker protein that bridges kinases associated with the B-cell receptor (BCR) with a multitude of signaling pathways , regulating biological outcomes of B-cell function and development. Plays a role in the activation of ERK/EPHB2 , MAP kinase p38 and JNK. Modulates AP1 activation. Important for the activation of NF-kappa-B and NFAT. Plays an important role in BCR-mediated PLCG1 and PLCG2 activation and Ca (2+) mobilization and is required for trafficking of the BCR to late endosomes. However , does not seem to be required for pre-BCR-mediated activation of MAP kinase and phosphatidyl-inositol 3 (PI3) kinase signaling. May be required for the RAC1-JNK pathway. Plays a critical role in orchestrating the pro-B cell to pre-B cell transition (By similarity) . Plays an important role in BCR-induced B-cell apoptosis. ,online information:BLNK mutation db ,PTM:Following BCR activation , phosphorylated on tyrosine residues by SYK and LYN. When phosphorylated , serves as a scaffold to assemble downstream targets of antigen activation , including PLCG1 , VAV1 , GRB2 and NCK1. Phosphorylation of Tyr-84 , Tyr-178 and Tyr-189 facilitates PLCG1 binding. Phosphorylation of Tyr-96 facilitates BTK binding. Phosphorylation of Tyr-72 facilitates VAV1 and NCK1 binding. Phosphorylation is required for both Ca (2+) and MAPK signaling pathways. ,similarity:Contains 1 SH2 domain. ,subcellular location:BCR activation results in the translocation to membrane fraction. ,subunit:Associates with PLCG1 , VAV1 and NCK1 in a B-cell antigen receptor-dependent fashion. Interacts with VAV3 , PLCG2 and GRB2. Interacts through its SH2 domain with CD79A. ,tissue specificity:Expressed in B-cell lineage and fibroblast cell lines (at protein level) . Highest levels of expression in the spleen , with lower levels in the liver , kidney , pancreas , small intestines and colon. ,

cell activation , immune system development , leukocyte differentiation , defense response , inflammatory response ,immune response , humoral immune response , intracellular signaling cascade , response to wounding , hemopoiesis ,lymphocyte differentiation , B cell differentiation , B cell activation , leukocyte activation , lymphocyte activation ,hemopoietic or lymphoid organ development ,

Cytoplasm . Cell membrane . BCR activation results in the translocation to membrane fraction.