Meta-Biol

• Pathways

Protein kinase C (PKC) activation enhances angiogenesis by participating in the intracellular signaling of vascular endothelial growth factor (VEGF) in endothelial cells. VEGF can activate several PKC isoforms including alpha, beta, delta and zeta isoforms. Their activation is preceded by the activation of PLC gamma (Suzuma et al. 2002, Xia et al. 1996, Takahashi et al. 1999, Wellner et al. 1999). Before Protein kinase C (PKC) is competent to respond to second messengers it must first be phosphorylated at three conserved positions: the activation loop and two positions at the carboxyl terminus of the protein (Dutil et al. 1998). The phosphorylation of the activation loop appears to occur first and is mediated by phosphoinositide dependent protein kinases (PDKs). PDK1 phosphorylates PKCs at a critical Thr (T) residue in the activation loop, a requirement for PKC to gain catalytic competency (Toker 2003).