FGR
Description
The FGR (FGR proto-oncogene, Src family tyrosine kinase) is a protein-coding gene located on chromosome 1.
FGR or fgr may refer to:
FGR is a non-receptor tyrosine-protein kinase involved in transmitting signals from cell surface receptors lacking kinase activity. It plays a crucial role in regulating immune responses, particularly in neutrophils, monocytes, macrophages, and mast cells. FGR contributes to various cellular processes, including cytoskeleton remodeling, phagocytosis, cell adhesion, and migration. It promotes mast cell degranulation, the release of inflammatory cytokines, and IgE-mediated anaphylaxis. FGR functions downstream of receptors binding the Fc region of immunoglobulins, such as MS4A2/FCER1B, FCGR2A, and FCGR2B. It also acts downstream of ITGB1 and ITGB2, regulating actin cytoskeleton reorganization, cell spreading, and adhesion. FGR can either activate or inhibit cellular responses depending on the context. In monocytes, it acts as a negative regulator of ITGB2 signaling, phagocytosis, and SYK activity. Conversely, in neutrophils and macrophages, FGR is essential for normal ITGB1 and ITGB2 signaling, cell spreading, and adhesion. FGR acts as a positive regulator of cell migration and regulates cytoskeleton reorganization through RAC1 activation. FGR phosphorylates SYK in vitro and promotes SYK-dependent activation of AKT1 and MAP kinase signaling. In antigen-stimulated mast cells, FGR phosphorylates PLD2, leading to PLD2 activation and the production of signaling molecules, lysophosphatidic acid, and diacylglycerol. FGR promotes activation of PIK3R1 and phosphorylates FASLG, regulating its ubiquitination and subsequent internalization. FGR also phosphorylates ABL1 and promotes phosphorylation of CBL, CTTN, PIK3R1, PTK2/FAK1, PTK2B/PYK2, and VAV2. FGR phosphorylates HCLS1 only after it has been phosphorylated by SYK, not when it is unphosphorylated. In conjunction with CLNK, FGR acts as a negative regulator of natural killer cell-activating receptors and inhibits interferon-gamma production.
FGR is also known as SRC2, c-fgr, c-src2, p55-Fgr, p55c-fgr, p58-Fgr, p58c-fgr.
