Title: Yeast 3-Phosphoinositide-dependent protein kinase-1 (PDK1) orthologs, Pkh1-3, differentially regulate phosphorylation of PKA and the PKB/S6K ortholog, Sch9
Authors: Voordeckers, Karin
Kimpe, Marlies
Haesendonckx, Steven
Louwet, Wendy
Versele, Matthias
Thevelein, Johan # ×
Issue Date: 2011
Publisher: American Society for Biochemistry and Molecular Biology
Series Title: Journal of Biological Chemistry vol:286 issue:25 pages:22017-22027
Abstract: Pkh1, 2 and 3 are the yeast orthologs of mammalian 3-Phosphoinositide-dependent Protein Kinase-1 (PDK1). Although essential for viability, their functioning remains poorly understood. Sch9, the yeast PKB and/or S6K ortholog, has been identified as one of their targets. We now show that in vitro interaction of Pkh1 and Sch9 depends on the hydrophobic PDK1 interacting fragment (PIF) pocket in Pkh1 and requires the complementary hydrophobic motif in Sch9. We demonstrate that Pkh1 phosphorylates Sch9 both in vitro and in vivo on its PDK1 site and that this phosphorylation is essential for a wild type cell size. In vivo phosphorylation on this site disappears during nitrogen deprivation and rapidly increases again upon nitrogen resupplementation. In addition, we show here for the first time that the PDK1 site in PKA is phosphorylated by Pkh1 in vitro, that this phosphorylation is Pkh dependent in vivo and occurs during or shortly after synthesis of the PKA catalytic subunits. Mutagenesis of the PDK1 site in Tpk1 abolishes binding of the regulatory subunit and cAMP dependency. As opposed to PDK1 site phosphorylation of Sch9, it is not regulated by nitrogen availability. These results bring new insight into the control and prevalence of PDK1 site phosphorylation in yeast by Pkh protein kinases.
ISSN: 0021-9258
Publication status: published
KU Leuven publication type: IT
Appears in Collections:Molecular Microbiology and Biotechnology Section - miscellaneous (-)
Centre of Microbial and Plant Genetics
× corresponding author
# (joint) last author

Files in This Item:

There are no files associated with this item.

Request a copy


All items in Lirias are protected by copyright, with all rights reserved.

© Web of science