Non-receptor tyrosine-protein kinase which phosphorylates DOK1 on tyrosine residues. Also phosphorylates KHDRBS1/SAM68 and VIM on tyrosine residues. Phosphorylation of KHDRBS1 is EGF-dependent. ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Interacts (via the SH2 and SH3 domains) with DOK1. Interacts with KHDRBS1/SAM68 and VIM. Localizes to punctate cytoplasmic structures. Higher expression in liver, lung, thymus and skin than in brain, kidney, heart and spleen (PubMed:9226137). In skin, highly expressed in keratinocytes (PubMed:9226137). Abundant in lung, liver, spleen, kidney and testis and is also detected in the cerebrum (PubMed:7935409). In the brain, expression is low at 11 dpc with higher levels detected in 15 dpc and postnatal brain. Expressed at low levels in adult brain. The N-terminal region regulates its kinase activity. No visible phenotype. Belongs to the protein kinase superfamily. Tyr protein kinase family. SRC subfamily.