Functional and Structural Mimicry of Cellular Protein Kinase A Anchoring Proteins by a Viral Oncoprotein

PLoS Pathogens

Jimmy D. Dikeakos¹  Michael J. Cohen¹  Joe S. Mymryk¹  Brennan S. Dirk¹  Gregory J. Fonseca¹  Cason R. King¹ 

[1] Department of Microbiology & Immunology, University of Western Ontario, London, Ontario, Canada

关键词: Small interfering RNAs;    Viral replication;    Immunoprecipitation;    Gene expression;    Co-immunoprecipitation;    HT1080 cells;    Sequence motif analysis;    Protein interactions;   

DOI  :  10.1371/journal.ppat.1005621

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

The oncoproteins of the small DNA tumor viruses interact with a plethora of cellular regulators to commandeer control of the infected cell. During infection, adenovirus E1A deregulates cAMP signalling and repurposes it for activation of viral gene expression. We show that E1A structurally and functionally mimics a cellular A-kinase anchoring protein (AKAP). E1A interacts with and relocalizes protein kinase A (PKA) to the nucleus, likely to virus replication centres, via an interaction with the regulatory subunits of PKA. Binding to PKA requires the N-terminus of E1A, which bears striking similarity to the amphipathic α-helical domain present in cellular AKAPs. E1A also targets the same docking-dimerization domain of PKA normally bound by cellular AKAPs. In addition, the AKAP like motif within E1A could restore PKA interaction to a cellular AKAP in which its normal interaction motif was deleted. During infection, E1A successfully competes with endogenous cellular AKAPs for PKA interaction. E1A’s role as a viral AKAP contributes to viral transcription, protein expression and progeny production. These data establish HAdV E1A as the first known viral AKAP. This represents a unique example of viral subversion of a crucial cellular regulatory pathway via structural mimicry of the PKA interaction domain of cellular AKAPs.

【 授权许可】

CC BY