Protein kinase C delta (deltaPKC)-annexin V interaction: a required step in deltaPKC translocation and function.

Abstract

Protein kinase C (PKC) plays a critical role in diseases such as cancer, stroke, and cardiac ischemia, and participates in a variety of signal transduction pathways such as apoptosis, cell proliferation, and tumor suppression. Though much is known about PKC downstream signaling events, the mechanisms of regulation of PKC activation and subsequent translocation have not been elucidated. Protein-protein interactions regulate and determine the specificity of many cellular signaling events. Such a specific protein-protein interaction is described here between deltaPKC and annexin V. We demonstrate, at physiologically relevant conditions, that a transient interaction between annexin V and deltaPKC occurs in cells after deltaPKC stimulation, but before deltaPKC translocates to the particulate fraction. Evidence of deltaPKC-annexin V binding is provided also by FRET and by in vitro binding studies. Dissociation of the deltaPKC-annexin V complex requires ATP and microtubule integrity. Furthermore, depletion of endogenous annexin V, but not annexin IV, with siRNA inhibits deltaPKC translocation following PKC stimulation. A rationally designed eight amino acid peptide, corresponding to the interaction site for deltaPKC on annexin V, inhibits deltaPKC translocation and deltaPKC-mediated function as evidenced by its protective effect in a model of myocardial infarction. Our data indicate that translocation of deltaPKC is not simply a diffusion-driven process, but is instead a multi-step event regulated by protein-protein interactions. We show that following cell activation, deltaPKC-annexin V binding is a transient and an essential step in the function of deltaPKC, thus identifying a new role for annexin V in PKC signaling and a new step in PKC activation.

• Authors: Viktoria Kheifets, Rachel Bright, Koichi Inagaki, Deborah Schechtman, Daria Mochly-Rosen
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 281 Issue 32 Pg. 23218-26 (Aug 11 2006) ISSN: 0021-9258 [Print] United States
• PMID: 16785226 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Annexin A5
• Protein Kinase C-delta

Topics

• Amino Acid Sequence
• Animals
• Annexin A5 (chemistry)
• CHO Cells
• Cricetinae
• Enzyme Activation
• HeLa Cells
• Humans
• Molecular Sequence Data
• Protein Binding
• Protein Kinase C-delta (chemistry)
• Protein Transport
• Sequence Homology, Amino Acid
• Signal Transduction