2o27
From Proteopedia
Structure of a class III RTK signaling assembly
Structural highlights
Function[SCF_MOUSE] Ligand for the receptor-type protein-tyrosine kinase KIT. Plays an essential role in the regulation of cell survival and proliferation, hematopoiesis, stem cell maintenance, gametogenesis, mast cell development, migration and function, and in melanogenesis. KITLG/SCF binding can activate several signaling pathways. Promotes phosphorylation of PIK3R1, the regulatory subunit of phosphatidylinositol 3-kinase, and subsequent activation of the kinase AKT1. KITLG/SCF and KIT also transmit signals via GRB2 and activation of RAS, RAF1 and the MAP kinases MAPK1/ERK2 and/or MAPK3/ERK1. KITLG/SCF and KIT promote activation of STAT family members STAT1, STAT3 and STAT5. KITLG/SCF and KIT promote activation of PLCG1, leading to the production of the cellular signaling molecules diacylglycerol and inositol 1,4,5-trisphosphate. KITLG/SCF acts synergistically with other cytokines, probably interleukins. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedStem cell factor (SCF) binds to and activates the KIT receptor, a class III receptor tyrosine kinase (RTK), to stimulate diverse processes including melanogenesis, gametogenesis and hematopoeisis. Dysregulation of KIT activation is associated with many cancers. We report a 2.5 A crystal structure of the functional core of SCF bound to the extracellular ligand-binding domains of KIT. The structure reveals a 'wrapping' SCF-recognition mode by KIT, in which KIT adopts a bent conformation to facilitate each of its first three immunoglobulin (Ig)-like domains to interact with SCF. Three surface epitopes on SCF, an extended loop, the B and C helices, and the N-terminal segment, contact distinct KIT domains, with two of the epitopes undergoing large conformational changes upon receptor binding. The SCF/KIT complex reveals a unique RTK dimerization assembly, and a novel recognition mode between four-helix bundle cytokines and Ig-family receptors. It serves as a framework for understanding the activation mechanisms of class III RTKs. Structural basis for stem cell factor-KIT signaling and activation of class III receptor tyrosine kinases.,Liu H, Chen X, Focia PJ, He X EMBO J. 2007 Feb 7;26(3):891-901. Epub 2007 Jan 25. PMID:17255936[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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