C-SRC (SH2 DOMAIN) COMPLEXED WITH ACE-PHOSPHOTYR-GLU-(N,N-DIPENTYL AMINE)
[SRC_HUMAN] Note=SRC kinase activity has been shown to be increased in several tumor tissues and tumor cell lines such as colon carcinoma cells.
[SRC_HUMAN] Non-receptor protein tyrosine kinase which is activated following engagement of many different classes of cellular receptors including immune response receptors, integrins and other adhesion receptors, receptor protein tyrosine kinases, G protein-coupled receptors as well as cytokine receptors. Participates in signaling pathways that control a diverse spectrum of biological activities including gene transcription, immune response, cell adhesion, cell cycle progression, apoptosis, migration, and transformation. Due to functional redundancy between members of the SRC kinase family, identification of the specific role of each SRC kinase is very difficult. SRC appears to be one of the primary kinases activated following engagement of receptors and plays a role in the activation of other protein tyrosine kinase (PTK) families. Receptor clustering or dimerization leads to recruitment of SRC to the receptor complexes where it phosphorylates the tyrosine residues within the receptor cytoplasmic domains. Plays an important role in the regulation of cytoskeletal organization through phosphorylation of specific substrates such as AFAP1. Phosphorylation of AFAP1 allows the SRC SH2 domain to bind AFAP1 and to localize to actin filaments. Cytoskeletal reorganization is also controlled through the phosphorylation of cortactin (CTTN). When cells adhere via focal adhesions to the extracellular matrix, signals are transmitted by integrins into the cell resulting in tyrosine phosphorylation of a number of focal adhesion proteins, including PTK2/FAK1 and paxillin (PXN). In addition to phosphorylating focal adhesion proteins, SRC is also active at the sites of cell-cell contact adherens junctions and phosphorylates substrates such as beta-catenin (CTNNB1), delta-catenin (CTNND1), and plakoglobin (JUP). Another type of cell-cell junction, the gap junction, is also a target for SRC, which phosphorylates connexin-43 (GJA1). SRC is implicated in regulation of pre-mRNA-processing and phosphorylates RNA-binding proteins such as KHDRBS1. Also plays a role in PDGF-mediated tyrosine phosphorylation of both STAT1 and STAT3, leading to increased DNA binding activity of these transcription factors. Involved in the RAS pathway through phosphorylation of RASA1 and RASGRF1. Plays a role in EGF-mediated calcium-activated chloride channel activation. Required for epidermal growth factor receptor (EGFR) internalization through phosphorylation of clathrin heavy chain (CLTC and CLTCL1) at 'Tyr-1477'. Involved in beta-arrestin (ARRB1 and ARRB2) desensitization through phosphorylation and activation of ADRBK1, leading to beta-arrestin phosphorylation and internalization. Has a critical role in the stimulation of the CDK20/MAPK3 mitogen-activated protein kinase cascade by epidermal growth factor. Might be involved not only in mediating the transduction of mitogenic signals at the level of the plasma membrane but also in controlling progression through the cell cycle via interaction with regulatory proteins in the nucleus. Plays an important role in osteoclastic bone resorption in conjunction with PTK2B/PYK2. Both the formation of a SRC-PTK2B/PYK2 complex and SRC kinase activity are necessary for this function. Recruited to activated integrins by PTK2B/PYK2, thereby phosphorylating CBL, which in turn induces the activation and recruitment of phosphatidylinositol 3-kinase to the cell membrane in a signaling pathway that is critical for osteoclast function. Promotes energy production in osteoclasts by activating mitochondrial cytochrome C oxidase. Phosphorylates DDR2 on tyrosine residues, thereby promoting its subsequent autophosphorylation. Phosphorylates RUNX3 and COX2 on tyrosine residues, TNK2 on 'Tyr-284' and CBL on 'Tyr-731'. Enhances DDX58/RIG-I-elicited antiviral signaling. Phosphorylates PDPK1 at 'Tyr-9', 'Tyr-373' and 'Tyr-376'. Phosphorylates BCAR1 at 'Tyr-128'.              
Publication Abstract from PubMed
Thermodynamic measurements, structural determinations, and molecular computations were applied to a series of peptide ligands of the pp60(c-src) SH2 domain in an attempt to understand the critical binding determinants for this class of molecules. Isothermal titration calorimetry (ITC) measurements were combined with structural data derived from X-ray crystallographic studies on 12 peptide-SH2 domain complexes. The peptide ligands studied fall into two general classes: (1) dipeptides of the general framework N-acetylphosphotyrosine (or phosphotyrosine replacement)-Glu or methionine (or S-methylcysteine)-X, where X represents a hydrophobic amine, and (2) tetra- or pentapeptides of the general framework N-acetylphosphotyrosine-Glu-Glu-Ile-X, where X represents either Glu, Gln, or NH2. Dipeptide analogs which featured X as either hexanolamine or heptanolamine were able to pick up new hydrogen bonds involving their hydroxyl groups within a predominantly lipophilic surface cavity. However, due to internal strain as well as the solvent accessibility of the new hydrogen bonds formed, no net increase in binding affinity was observed. Phosphatase-resistant benzylmalonate and alpha,alpha-difluorobenzyl phosphonate analogs of phosphotyrosine retained some binding affinity for the pp60(c-src) SH2 domain but caused local structural perturbations in the phosphotyrosine-binding site. In the case where a reversible covalent thiohemiacetal was formed between a formylated phosphotyrosine analog and the thiol side chain of Cys-188, deltaS was 25.6 cal/(mol K) lower than for the nonformylated phosphotyrosine parent. Normal mode calculations show that the dramatic decrease in entropy observed for the covalent thiohemiacetal complex is due to the inability of the phosphotyrosine moiety to transform lost rotational and translational degrees of freedom into new vibrational modes.
Peptide ligands of pp60(c-src) SH2 domains: a thermodynamic and structural study.,Charifson PS, Shewchuk LM, Rocque W, Hummel CW, Jordan SR, Mohr C, Pacofsky GJ, Peel MR, Rodriguez M, Sternbach DD, Consler TG Biochemistry. 1997 May 27;36(21):6283-93. PMID:9174343
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.