Function

Protein kinase C (PKC) phosphorylates serine or threonine residues in proteins. PKC act in signal transduction pathways[1]. PKC consists of regulatory domain hinged to a catalytic domain. The regulatory domain contains the C1 region which binds diacylglycerol (DAG) and phorbol esters and the C2 domain which is a Ca+2 sensor. PKC contains Pleckstrin Homology (PH) domain which binds phosphatidylinositol lipids (PTDINS). The PH domain is found in proteins involved in intracellular signaling.

  • Conventional PKC (CPKC) - α, β1, β2, γ – are activated by DAG, Ca+2 and a phospholipid.
  • Novel PKC (NPKC) – δ, ε, η, θ – are activated by DAG.
  • Atypical PKC (APKC) do not require DAG or Ca+2 for activation.

Relevance

Activation of PKC and elevated levels of DAG are associated with vascular abnormalities in retinal, renal and cardiovascular tissues. Inhibitors of PKC-β are tested for prevention of diabetic complications[2]. Activation of PKC-α and PKC-β are linked to malignant phenotypes while PKC-δ is thought to mediate anti-cancer effects[3].

Structural highlights

near the [4]. Water molecules are shown as red spheres.

3D structures of protein kinase C

Protein kinase C 3D structures


Rat protein kinase α C2 domain complex with phosphatidylinositol, phosphate and Ca+2 ion (green), 3gpe

Drag the structure with the mouse to rotate

ReferencesReferences

  1. Idris I, Gray S, Donnelly R. Protein kinase C activation: isozyme-specific effects on metabolism and cardiovascular complications in diabetes. Diabetologia. 2001 Jun;44(6):659-73. PMID:11440359 doi:http://dx.doi.org/10.1007/s001250051675
  2. Koya D, King GL. Protein kinase C activation and the development of diabetic complications. Diabetes. 1998 Jun;47(6):859-66. PMID:9604860
  3. Koivunen J, Aaltonen V, Peltonen J. Protein kinase C (PKC) family in cancer progression. Cancer Lett. 2006 Apr 8;235(1):1-10. PMID:15907369 doi:http://dx.doi.org/10.1016/j.canlet.2005.03.033
  4. Guerrero-Valero M, Ferrer-Orta C, Querol-Audi J, Marin-Vicente C, Fita I, Gomez-Fernandez JC, Verdaguer N, Corbalan-Garcia S. Structural and mechanistic insights into the association of PKC{alpha}-C2 domain to PtdIns(4,5)P2. Proc Natl Acad Sci U S A. 2009 Apr 3. PMID:19346474

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