title: AMP-activated protein kinase phosphorylates EMCV, TMEV and SafV leader proteins at different sites.
abstract: Cardioviruses of the Encephalomyocarditis virus (EMCV) and Theilovirus species encode small, amino-terminal proteins called Leaders (L). Phosphorylation of the EMCV L (LE) at two distinct sites by CK2 and Syk kinases is important for virus-induced Nup phosphorylation and nucleocytoplasmic trafficking inhibition. Despite similar biological activities, the LE phosphorylation sites are not conserved in the Theiloviruses, Saffold virus (LS, SafV) or Theiler׳s murine encephalitis virus (LT, TMEV) sequences even though these proteins also become phosphorylated in cells and cell-free extracts. Site prediction algorithms, combined with panels of site-specific protein mutations now identify analogous, but not homologous phosphorylation sites in the Ser/Thr and Theilo protein domains of LT and LS, respectively. In both cases, recombinant AMP-activated kinase (AMPK) was reactive with the proteins at these sites, and also with LE, modifying the same residue recognized by CK2.
authors.affiliation: Institute for Molecular Virology and Department of Biochemistry, Robert M. Bock Laboratories, University of Wisconsin-Madison, 1525 Linden Dr., Madison, WI 53706, USA.
authors.forename: Holly A
authors.initials: HA
authors.lastname: Basta
authors.affiliation: Institute for Molecular Virology and Department of Biochemistry, Robert M. Bock Laboratories, University of Wisconsin-Madison, 1525 Linden Dr., Madison, WI 53706, USA. Electronic address: acpalmen@wisc.edu.
authors.forename: Ann C
authors.initials: AC
authors.lastname: Palmenberg
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000818:Animals; D017943:Cardiovirus / Q000502:physiology*; D004686:Encephalomyocarditis virus / Q000502:physiology*; D051379:Mice; D011499:Protein Processing, Post-Translational; D017945:Theilovirus / Q000502:physiology*; D015678:Viral Structural Proteins / Q000378:metabolism*
chemical_list: D015678:Viral Structural Proteins; D055372:AMP-Activated Protein Kinases
keywords: AMPK; Cardiovirus; Leader protein; Phosphorylation