anti-Lyn, pAb

The members of the Src-family kinases are Src, Lyn, Fyn, Yes, Hck, Lck, Fgr, Blk, and Yrk. Each of these have a common structure consisting of an unique domain at the N-terminal, followed by SH3, SH2 and tyrosine kinase domains. In immume cells, the Src-family kinases play roles as critical regulators of a large number of intracellular signaling pathways, including integrin signaling pathway. Integrins are major cellular receptor that mediate cell to cell and cell to substratum interactions. The intracellular protein kinase Lyn participates both positively and negatively in B cell, mast cell, platelet and myeloid cell signaling. Lyn is the predominantly expressed Src-family kinase in B cells and its positive role is done through phosphorylation of the Igα and Igβ subunits of B cell receptor. Genetic deletion of Lyn results in autoimmunity, renal disease and premature mortality in mice, and generation of hyperactive Lyn results in the same phenotype, revealing the importance of the balance of Lyn signaling. Down regulates expression of stem cell growth factor receptor (KIT). Acts as an effector of EpoR (erythropoietin receptor) in controlling KIT expression and may play a central role in erythroid differentiation during the switch between proliferation and maturation By similarity. Acts as a positive regulator of cell movement while negatively regulating adhesion to stromal cells by inhibiting the ICAM-1-binding activity of β-2 integrins. Acts as the mediator that relays suppressing signals from the chemokine receptor CXCR4 to β-2 integrin LFA-1 in hematopoietic precursors. Involved in induction of stress-activated protein kinase (SAPK), but not ERK or p38 MAPK, in response to genotoxic agents. Induces SAPK by a MKK7- and MEKK1-dependent mechanism. The LYN -> MEKK1 -> MKK7 -> SAPK pathway is functional in the induction of apoptosis by genotoxic agents.