A Peptide-Based Target Screen Implicates the Protein Kinase CK2 in the Global Regulation of Caspase Signaling

Authors

James S. Duncan, The University of Western Ontario
Jacob P. Turowec, The University of Western Ontario
Kelly E. Duncan, The University of Western Ontario
Greg Vilk, The University of Western Ontario
Chenggang Wu, The University of Western Ontario
Bernhard Lüscher, RWTH Aachen University, Aachen, Germany
Shawn S.-C. Li, The University of Western Ontario
Greg B. Gloor, The University of Western Ontario
David W. Litchfield, The University of Western OntarioFollow

Document Type

Article

Publication Date

5-10-2011

Journal

Science Signaling

Volume

4

Issue

172

First Page

30

Last Page

30

URL with Digital Object Identifier

http://dx.doi.org/10.1126/scisignal.2001682

Abstract

The convergence of caspase and protein kinase signaling pathways has become increasingly evident, as illustrated by the protection of caspase substrates from cleavage upon undergoing phosphorylation at or near to their caspase recognition motifs. To investigate the global role of phosphorylation in the regulation of caspase signaling, we designed a peptide match program to identify sequences from the human proteome that contained overlapping recognition motifs for caspases and kinases. We identified the protein kinase CK2 as the most prominent kinase with a consensus site for phosphorylation that overlapped with caspase recognition motifs. We then evaluated potential targets of CK2 and caspases by combining peptide array target screens with identification of caspase substrates. We identified numerous shared candidate targets of CK2 and caspases, including procaspase-3, which functions at a level at which both intrinsic and extrinsic apoptotic signals converge. Together, these data support a role for CK2-dependent phosphorylation as a global mechanism for inhibiting caspase signaling pathways.

Notes

The summary and full text reprint of this article are freely available online from Science Signaling.