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) (Probable). 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) (By similarity). 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 (Probable). Also plays a role in PDGF-mediated tyrosine phosphorylation of both STAT1 and STAT3, leading to increased DNA binding activity of these transcription factors (PubMed:9344858). Involved in the RAS pathway through phosphorylation of RASA1 and RASGRF1. Plays a role in EGF-mediated calcium-activated chloride channel activation (By similarity). 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 GRK2, 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 (Probable). 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 (By similarity). 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 (PubMed:14739300). Promotes energy production in osteoclasts by activating mitochondrial cytochrome C oxidase (PubMed:12615910). 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-738'. Enhances DDX58/RIG-I-elicited antiviral signaling. Phosphorylates PDPK1 at 'Tyr-9', 'Tyr-373' and 'Tyr-376'. Phosphorylates BCAR1 at 'Tyr-226'. Phosphorylates CBLC at multiple tyrosine residues, phosphorylation at 'Tyr-341' activates CBLC E3 activity. Phosphorylates synaptic vesicle protein synaptophysin (SYP) (By similarity). Involved in anchorage-independent cell growth (By similarity). Required for podosome formation (PubMed:21525037). Mediates IL6 signaling by activating YAP1-NOTCH pathway to induce inflammation-induced epithelial regeneration (PubMed:25731159). Non-receptor protein tyrosine kinase which phosphorylates synaptophysin with high affinity. Non-receptor protein tyrosine kinase which shows higher basal kinase activity than isoform 1, possibly due to weakened intramolecular interactions which enhance autophosphorylation of Tyr-418 and subsequent activation (By similarity). The SH3 domain shows reduced affinity with the linker sequence between the SH2 and kinase domains which may account for the increased basal activity (By similarity). Displays altered substrate specificity compared to isoform 1, showing weak affinity for synaptophysin and for peptide substrates containing class I or class II SH3 domain-binding motifs (By similarity). Plays a role in L1CAM-mediated neurite elongation, possibly by acting downstream of L1CAM to drive cytoskeletal rearrangements involved in neurite outgrowth (By similarity). ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Phosphorylation by CSK at Tyr-529 inhibits kinase activity. Inhibitory phosphorylation at Tyr-529 is enhanced by heme. Further phosphorylation by CDK1 partially reactivates CSK-inactivated SRC and facilitates complete reactivation by protein tyrosine phosphatase PTPRC. Integrin engagement stimulates kinase activity. Phosphorylation by PTK2/FAK1 enhances kinase activity. Butein and pseudosubstrate-based peptide inhibitors like CIYKYYF act as inhibitors. Phosphorylation at Tyr-418 increases kinase activity. Part of a complex comprised of PTPRA, BCAR1, BCAR3 (via SH2 domain) and SRC; the formation of the complex is dependent on integrin mediated-tyrosine phosphorylation of PTPRA (PubMed:22801373). Interacts with CDCP1, TGFB1I1 and TOM1L2 (By similarity). Interacts with DDEF1/ASAP1 via its SH3 domain (PubMed:9819391). Interacts with CCPG1 (PubMed:17000758). Interacts with the cytoplasmic domain of MUC1, phosphorylates it and increases binding of MUC1 with beta-catenin (By similarity). Interacts with RALGPS1 via its SH3 domain (By similarity). Interacts with CAV2 (tyrosine phosphorylated form) (By similarity). Interacts (via the SH3 domain and the protein kinase domain) with ARRB1; the interaction is independent of the phosphorylation state of SRC C-terminus (By similarity). Interacts with FCAMR and PXN (By similarity). Interacts with ARRB2 (PubMed:19122674). Interacts with ARRB1 (By similarity). Interacts with SRCIN1 (By similarity). Interacts with NDFIP2 and more weakly with NDFIP1 (By similarity). Interacts with PIK3CA and/or PIK3C2B, PTK2/FAK1, ESR1 (dimethylated on arginine) and FAK (PubMed:14739300). Interacts (via SH2 and SH3 domain) with TNK2 (By similarity). Interacts (via protein kinase domain) with the tyrosine phosphorylated form of RUNX3 (via runt domain) (By similarity). Interacts with TRAF3 (via RING-type zinc finger domain) (By similarity). Interacts with DDX58, MAVS and TBK1 (By similarity). Interacts (via SH2 domain) with RACK1; the interaction is enhanced by tyrosine phosphorylation of RACK1 and inhibits SRC activity (By similarity). Interacts (via SH2 domain) with the 'Tyr-402' phosphorylated form of PTK2B/PYK2 (PubMed:14739300). Interacts (via SH2 domain) with FLT3 (tyrosine phosphorylated) (PubMed:16684964). Identified in a complex containing FGFR4, NCAM1, CDH2, PLCG1, FRS2, SRC, SHC1, GAP43 and CTTN (PubMed:11433297). Interacts with EPHB1; activates the MAPK/ERK cascade to regulate cell migration (PubMed:12925710). Interacts with ERBB2 and STAT1 (PubMed:7542762, PubMed:9344858). Interacts with PDGFRA (tyrosine phosphorylated) (PubMed:14644164). Interacts with CSF1R (PubMed:7681396). Interacts (via SH2 domain) with the 'Tyr-9' phosphorylated form of PDPK1 (By similarity). Interacts with DDR2 (By similarity). Interacts with AMOTL2; this interaction regulates the translocation of phosphorylated SRC to peripheral cell-matrix adhesion sites (By similarity). Interacts with DDR1 and DAB2 (PubMed:20093046). Interacts with TRAP1 (By similarity). Interacts with CBLC; the interaction is enhanced when SRC is phosphorylated at 'Tyr-424' (By similarity). Interacts with ARHGEF5 (PubMed:21525037). Interacts (via cytoplasmic domain) with CEACAM1 (via SH2 domain); this interaction is regulated by trans-homophilic cell adhesion (By similarity). Interacts with MPP2 (By similarity). Interacts with PRR7 (By similarity). Interacts (via kinase domain and to a lesser extent the SH2 domain) directly with PDLIM4; this interaction results in PTPN13-mediated dephosphorylation of this protein leading to its inactivation (By similarity). Interacts with P85 (PIK3R1 or PIK3R2) (By similarity). Interacts with HNRNPA2B1 (PubMed:31320558). Interacts with IL6ST/gp130 (By similarity). Interacts (via SH3 domain) with PELP1 in the presence of 17-beta-estradiol (By similarity). Interacts with AMBRA1 (PubMed:28362576). Localizes to focal adhesion sites following integrin engagement (PubMed:22801373). Localization to focal adhesion sites requires myristoylation and the SH3 domain. Colocalizes with PDLIM4 at the perinuclear region, but not at focal adhesions. Myristoylated at Gly-2, and this is essential for targeting to membranes. Dephosphorylated at Tyr-529 by PTPRJ (By similarity). Phosphorylated on Tyr-529 by c-Src kinase (CSK). The phosphorylated form is termed pp60c-src. Dephosphorylated by PTPRJ at Tyr-418. Normally maintained in an inactive conformation with the SH2 domain engaged with Tyr-529, the SH3 domain engaged with the SH2-kinase linker, and Tyr-418 dephosphorylated. Dephosphorylation of Tyr-529 as a result of protein tyrosine phosphatase (PTP) action disrupts the intramolecular interaction between the SH2 domain and Tyr-529, Tyr-418 can then become autophosphorylated, resulting in SRC activation. Phosphorylation of Tyr-529 by CSK allows this interaction to reform, resulting in SRC inactivation. CDK5-mediated phosphorylation at Ser-74 targets SRC to ubiquitin-dependent degradation and thus leads to cytoskeletal reorganization. Phosphorylated by PTK2/FAK1; this enhances kinase activity. Phosphorylated by PTK2B/PYK2; this enhances kinase activity (By similarity). Upon activation of IL6ST by IL6, Tyr-418 is phosphorylated and Tyr-529 dephosphorylated (PubMed:25731159). Displays reduced levels of autophosphorylation at Tyr-418 compared to isoform 2. Displays enhanced levels of autophosphorylation at Tyr-418 compared to isoform 1. S-nitrosylation is important for activation of its kinase activity. Ubiquitinated in response to CDK5-mediated phosphorylation. Ubiquitination mediated by CBLC requires SRC autophosphorylation at Tyr-418 and may lead to lysosomal degradation (By similarity). Belongs to the protein kinase superfamily. Tyr protein kinase family. SRC subfamily.