Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.2 (PDK1)
 2,238 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Akt (= protein kinase B), a subfamily of the AGC serine/threonine kinases, plays critical roles in survival, proliferation, glucose metabolism, and other cellular functions. Akt activation requires the recruitment of the enzyme to the plasma membrane by interacting with membrane-bound lipid products of phosphatidylinositol 3-kinase. Membrane-bound Akt is then phosphorylated at two sites for its full activation; Thr-308 in the activation loop of the kinase domain is phosphorylated by 3-phosphoinositide-dependent kinase-1 (PDK1) and Ser-473 in the C-terminal hydrophobic motif by a putative kinase PDK2. The identity of PDK2 has been elusive. Here we present evidence that conventional isoforms of protein kinase C (PKC), particularly PKCbetaII, can regulate Akt activity by directly phosphorylating Ser-473 in vitro and in IgE/antigen-stimulated mast cells. By contrast, PKCbeta is not required for Ser-473 phosphorylation in mast cells stimulated with stem cell factor or interleukin-3, in serum-stimulated fibroblasts, or in antigen receptor-stimulated T or B lymphocytes. Therefore, PKCbetaII appears to work as a cell type- and stimulus-specific PDK2.
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PMID:Protein kinase C betaII regulates Akt phosphorylation on Ser-473 in a cell type- and stimulus-specific fashion. 1536 15

Stem cell factor (SCF) has important roles in the proliferation and differentiation of hematopoietic stem cells. The complex of c-Kit and its ligand SCF induce hematopoiesis, melanogenesis, and gametogenesis. However, the mechanism by which SCF induces cell proliferation in the human megakaryoblastic leukemia cell line, MO7e, and the signaling molecules involved, especially in downstream signaling of c-Kit, remain unclear. Here, we show that pharmacological inhibition of the PI3K pathway inhibits SCF/c-Kit signaling and cell proliferation. In addition, we find that the Shc/PDK1/PKC/Akt/c-raf signaling cascade is essential for SCF/c-Kit signal pathway. Our results also suggest that ERK5 is activated and translocated to the nucleus, activating CREB and STAT3. Interestingly, chrysin shuts down the SCF/c-Kit complex-induced signaling cascade. Taken together, these studies give additional insight into the molecular mechanism of SCF/c-Kit-induced cell proliferation and its inverse agonist, chrysin. Finally, these findings enhance our understanding of MO7e cell proliferation.
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PMID:Chrysin inhibited stem cell factor (SCF)/c-Kit complex-induced cell proliferation in human myeloid leukemia cells. 1749 88