Non-receptor protein tyrosine kinase that is involved in the regulation of cell growth and survival, apoptosis, cell-cell adhesion, cytoskeleton remodeling, and differentiation. Stimulation by receptor tyrosine kinases (RTKs) including EGFR, PDGFR, CSF1R and FGFR leads to recruitment of YES1 to the phosphorylated receptor, and activation and phosphorylation of downstream substrates. Upon EGFR activation, promotes the phosphorylation of PARD3 to favor epithelial tight junction assembly.

Participates in the phosphorylation of specific junctional components such as CTNND1 by stimulating the FYN and FER tyrosine kinases at cell-cell contacts. Upon T-cell stimulation by CXCL12, phosphorylates collapsin response mediator protein 2/DPYSL2 and induces T-cell migration. Participates in CD95L/FASLG signaling pathway and mediates AKT-mediated cell migration.

Plays a role in cell cycle progression by phosphorylating the cyclin-dependent kinase 4/CDK4 thus regulating the G1 phase. Also involved in G2/M progression and cytokinesis. Catalyzes phosphorylation of organic cation transporter OCT2 which induces its transport activity (PubMed:26979622)

Interacts with YAP1 and CSF1R (By similarity). Interacts with CTNND1; this interaction allows YES1-mediated activation of FYN and FER and subsequent phosphorylation of CTNND1 (By similarity). Interacts with FASLG.

Interacts with IL6ST/gp130 (PubMed:25731159). Interacts with SCRIB, when YES1 is in a closed conformation; the interaction facilitates YES1 autophosphorylation (PubMed:33730553)

Expressed in the epithelial cells of renal proximal tubules and stomach as well as hematopoietic cells in the bone marrow and spleen in the fetal tissues. In adult, expressed in epithelial cells of the renal proximal tubules and present in keratinocytes in the basal epidermal layer of epidermis