PKA isoforms coordinate mRNA fate during nutrient starvation.
A variety of stress conditions induce mRNA and protein aggregation into mRNA silencing foci, but the signalling pathways mediating these responses are still elusive. Previously we demonstrated that PKA catalytic isoforms Tpk2 and Tpk3 localise with processing and stress bodies in Saccharomyces cerevisiae. Here, we show that Tpk2 and Tpk3 are associated with translation initiation factors Pab1 and Rps3 in exponentially growing cells. Glucose starvation promotes the loss of interaction between Tpk and initiation factors followed by their accumulation into processing bodies. Analysis of mutants of the individual PKA isoform genes has revealed that the TPK3 or TPK2 deletion affects the capacity of the cells to form granules and arrest translation properly in response to glucose starvation or stationary phase. Moreover, we demonstrate that PKA controls Rpg1 and eIF4G(1) protein abundance, possibly controlling cap-dependent translation. Taken together, our data suggest that the PKA pathway coordinates multiple stages in the fate of mRNAs in association with nutritional environment and growth status of the cell.
Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires,  Argentina.
Vanesa
V
Tudisca
Clare
C
Simpson
Lydia
L
Castelli
Jennifer
J
Lui
Nathaniel
N
Hoyle
Silvia
S
Moreno
Mark
M
Ashe
Paula
P
Portela
D003470:Culture Media; D054751:Cyclic AMP-Dependent Protein Kinase Catalytic Subunits / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D003594:Cytoplasmic Granules / Q000201:enzymology; D039621:Eukaryotic Initiation Factor-3 / Q000378:metabolism; D039603:Eukaryotic Initiation Factor-4G / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005947:Glucose / Q000172:deficiency; D007527:Isoenzymes / Q000378:metabolism; D010442:Peptide Chain Initiation, Translational; D039102:Poly(A)-Binding Proteins / Q000378:metabolism; D021122:Protein Subunits / Q000378:metabolism; D021381:Protein Transport; D012333:RNA, Messenger / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D013312:Stress, Physiological
D003470:Culture Media; D039621:Eukaryotic Initiation Factor-3; D039603:Eukaryotic Initiation Factor-4G; D007527:Isoenzymes; D039102:Poly(A)-Binding Proteins; D021122:Protein Subunits; D012333:RNA, Messenger; C111889:RPG1 protein, S cerevisiae; C501334:RPS3 protein, S cerevisiae; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; C107740:TIF4631 protein, S cerevisiae; C450100:pab1 protein, S cerevisiae; D054751:Cyclic AMP-Dependent Protein Kinase Catalytic Subunits; D017868:Cyclic AMP-Dependent Protein Kinases; C457179:TPK2 protein, S cerevisiae; C579078:Tpk1 protein, S cerevisiae; C509333:Tpk3 protein, S cerevisiae; D005947:Glucose