3gpe
From Proteopedia
Crystal Structure Analysis of PKC (alpha)-C2 domain complexed with Ca2+ and PtdIns(4,5)P2
Structural highlights
Function[KPCA_RAT] Calcium-activated, phospholipid- and diacylglycerol (DAG)-dependent serine/threonine-protein kinase that is involved in positive and negative regulation of cell proliferation, apoptosis, differentiation, migration and adhesion, cardiac hypertrophy, angiogenesis, platelet function and inflammation, by directly phosphorylating targets such as RAF1, BCL2, CSPG4, TNNT2/CTNT, or activating signaling cascade involving MAPK1/3 (ERK1/2) and RAP1GAP. Depending on the cell type, is involved in cell proliferation and cell growth arrest by positive and negative regulation of the cell cycle. Can promote cell growth by phosphorylating and activating RAF1, which mediates the activation of the MAPK/ERK signaling cascade, and/or by up-regulating CDKN1A, which facilitates active cyclin-dependent kinase (CDK) complex formation. In cells stimulated by the phorbol ester PMA, can trigger a cell cycle arrest program which is associated with the accumulation of the hyper-phosphorylated growth-suppressive form of RB1 and induction of the CDK inhibitors CDKN1A and CDKN1B. Depending on the cell type, exhibits anti-apoptotic function and protects cells from apoptosis by suppressing the p53/TP53-mediated activation of IGFBP3, or mediates anti-apoptotic action by phosphorylating BCL2. During macrophage differentiation induced by macrophage colony-stimulating factor (CSF1), is translocated to the nucleus and is associated with macrophage development. After wounding, translocates from focal contacts to lamellipodia and participates in the modulation of desmosomal adhesion. Plays a role in cell motility by phosphorylating CSPG4, which induces association of CSPG4 with extensive lamellipodia at the cell periphery and polarization of the cell accompanied by increases in cell motility. Negatively regulates myocardial contractility and positively regulates angiogenesis, platelet aggregation and thrombus formation in arteries. Mediates hypertrophic growth of neonatal cardiomyocytes, in part through a MAPK1/3 (ERK1/2)-dependent signaling pathway, and upon PMA treatment, is required to induce cardiomyocyte hypertrophy up to heart failure and death, by increasing protein synthesis, protein-DNA ratio and cell surface area. Regulates cardiomyocyte function by phosphorylating cardiac troponin T (TNNT2/CTNT), which induces significant reduction in actomyosin ATPase activity, myofilament calcium sensitivity and myocardial contractility. In angiogenesis, is required for full endothelial cell migration, adhesion to vitronectin (VTN), and vascular endothelial growth factor A (VEGFA)-dependent regulation of kinase activation and vascular tube formation. Involved in the stabilization of VEGFA mRNA at post-transcriptional level and mediates VEGFA-induced cell proliferation. In the regulation of calcium-induced platelet aggregation, mediates signals from the CD36/GP4 receptor for granule release, and activates the integrin heterodimer ITGA2B-ITGB3 through the RAP1GAP pathway for adhesion. During response to lipopolysaccharides (LPS), may regulate selective LPS-induced macrophage functions involved in host defense and inflammation. But in some inflammatory responses, may negatively regulate NF-kappa-B-induced genes, through IL1A-dependent induction of NF-kappa-B inhibitor alpha (NFKBIA/IKBA). Upon stimulation with 12-O-tetradecanoylphorbol-13-acetate (TPA), phosphorylates EIF4G1, which modulates EIF4G1 binding to MKNK1 and may be involved in the regulation of EIF4E phosphorylation. Phosphorylates KIT, leading to inhibition of KIT activity.[1] [2] [3] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedC2 domains are widely-spread protein signaling motifs that in classical PKCs act as Ca(2+)-binding modules. However, the molecular mechanisms of their targeting process at the plasma membrane remain poorly understood. Here, the crystal structure of PKCalpha-C2 domain in complex with Ca(2+), 1,2-dihexanoyl-sn-glycero-3-[phospho-l-serine] (PtdSer), and 1,2-diayl-sn-glycero-3-[phosphoinositol-4,5-bisphosphate] [PtdIns(4,5)P(2)] shows that PtdSer binds specifically to the calcium-binding region, whereas PtdIns(4,5)P(2) occupies the concave surface of strands beta3 and beta4. Strikingly, the structure reveals a PtdIns(4,5)P(2)-C2 domain-binding mode in which the aromatic residues Tyr-195 and Trp-245 establish direct interactions with the phosphate moieties of the inositol ring. Mutations that abrogate Tyr-195 and Trp-245 recognition of PtdIns(4,5)P(2) severely impaired the ability of PKCalpha to localize to the plasma membrane. Notably, these residues are highly conserved among C2 domains of topology I, and a general mechanism of C2 domain-membrane docking mediated by PtdIns(4,5)P(2) is presented. Structural and mechanistic insights into the association of PKC{alpha}-C2 domain to PtdIns(4,5)P2.,Guerrero-Valero M, Ferrer-Orta C, Querol-Audi J, Marin-Vicente C, Fita I, Gomez-Fernandez JC, Verdaguer N, Corbalan-Garcia S Proc Natl Acad Sci U S A. 2009 Apr 3. PMID:19346474[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
| ||||||||||||||||||||||||
Categories: Protein kinase C | Rattus norvegicus | Ferrer-Orta, C | Fita, I | Querol-Audi, J | Verdaguer, N | Atp-binding | C2 domain | Calcium/phospholipid binding domain | Kinase | Metal-binding | Nucleotide-binding | Phorbol-ester binding | Phosphatidil serine | Phosphoprotein | Protein kinase | Serine/threonine-protein kinase | Signaling protein | Transferase | Zinc-finger
