PMID: 27133022

Authors:

Simon B, Huart AS, Temmerman K, Vahokoski J, Mertens HD, Komadina D, Hoffmann JE, Yumerefendi H, Svergun DI, Kursula P, Schultz C, McCarthy AA, Hart DJ, Wilmanns M

Title:

Death-Associated Protein Kinase Activity Is Regulated by Coupled Calcium/Calmodulin Binding to Two Distinct Sites.

Journal:

Structure. 2016 Apr 20. pii: S0969-2126(16)30030-2. doi:, 10.1016/j.str.2016.03.020.

Abstract:

The regulation of many protein kinases by binding to calcium/calmodulin connects two principal mechanisms in signaling processes: protein phosphorylation and responses to dose- and time-dependent calcium signals. We used the calcium/calmodulin-dependent members of the death-associated protein kinase (DAPK) family to investigate the role of a basic DAPK signature loop near the kinase active site. In DAPK2, this loop comprises a novel dimerization-regulated calcium/calmodulin-binding site, in addition to a well-established calcium/calmodulin site in the C-terminal autoregulatory domain. Unexpectedly, impairment of the basic loop interaction site completely abolishes calcium/calmodulin binding and DAPK2 activity is reduced to a residual level, indicative of coupled binding to the two sites. This contrasts with the generally accepted view that kinase calcium/calmodulin interactions are autonomous of the kinase catalytic domain. Our data establish an intricate model of multi-step kinase activation and expand our understanding of how calcium binding connects with other mechanisms involved in kinase activity regulation.