scholarly journals Protein Kinase A, TOR, and Glucose Transport Control the Response to Nutrient Repletion in Saccharomyces cerevisiae

2007 ◽  
Vol 7 (2) ◽  
pp. 358-367 ◽  
Author(s):  
Matthew G. Slattery ◽  
Dritan Liko ◽  
Warren Heideman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Glucose Transport ◽  
Transcriptional Response ◽  
Nutrient Sensing ◽  
Fresh Medium ◽  
Transcriptional Responses ◽  
Nutrient Regulation ◽  
Kinase A

ABSTRACT Nutrient repletion leads to substantial restructuring of the transcriptome in Saccharomyces cerevisiae. The expression levels of approximately one-third of all S. cerevisiae genes are altered at least twofold when a nutrient-depleted culture is transferred to fresh medium. Several nutrient-sensing pathways are known to play a role in this process, but the relative contribution that each pathway makes to the total response has not been determined. To better understand this, we used a chemical-genetic approach to block the protein kinase A (PKA), TOR (target of rapamycin), and glucose transport pathways, alone and in combination. Of the three pathways, we found that loss of PKA produced the largest effect on the transcriptional response; however, many genes required both PKA and TOR for proper nutrient regulation. Those genes that did not require PKA or TOR for nutrient regulation were dependent on glucose transport for either nutrient induction or repression. Therefore, loss of these three pathways is sufficient to prevent virtually the entire transcriptional response to fresh medium. In the absence of fresh medium, activation of the cyclic AMP/PKA pathway does not induce cellular growth; nevertheless, PKA activation induced a substantial fraction of the PKA-dependent genes. In contrast, the absence of fresh medium strongly limited gene repression by PKA. These results account for the signals needed to generate the transcriptional responses to glucose, including induction of growth genes required for protein synthesis and repression of stress genes, as well as the classical glucose repression and hexose transporter responses.

scholarly journals Protein Kinase A and Sch9 Cooperatively Regulate Induction of Autophagy in Saccharomyces cerevisiae

2007 ◽  
Vol 18 (10) ◽  
pp. 4180-4189 ◽  
Author(s):  
Tomohiro Yorimitsu ◽  
Shadia Zaman ◽  
James R. Broach ◽  
Daniel J. Klionsky
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transcription Factors ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Signaling Pathways ◽  
Nutrient Sensing ◽  
Regulatory Mechanisms ◽  
Eukaryotic Cells ◽  
Tor Kinase ◽  
Kinase A

Autophagy is a highly conserved, degradative process in eukaryotic cells. The rapamycin-sensitive Tor kinase complex 1 (TORC1) has a major role in regulating induction of autophagy; however, the regulatory mechanisms are not fully understood. Here, we find that the protein kinase A (PKA) and Sch9 signaling pathways regulate autophagy cooperatively in yeast. Autophagy is induced in cells when PKA and Sch9 are simultaneously inactivated. Mutant alleles of these kinases bearing a mutation that confers sensitivity to the ATP-analogue inhibitor C3-1′-naphthyl-methyl PP1 revealed that autophagy was induced independently of effects on Tor kinase. The PKA–Sch9-mediated autophagy depends on the autophagy-related 1 kinase complex, which is also essential for TORC1-regulated autophagy, the transcription factors Msn2/4, and the Rim15 kinase. The present results suggest that autophagy is controlled by the signals from at least three partly separate nutrient-sensing pathways that include PKA, Sch9, and TORC1.

scholarly journals Transcriptional responses to glucose in Saccharomyces cerevisiae strains lacking a functional protein kinase A

BMC Genomics ◽  
2011 ◽  
Vol 12 (1) ◽  
Author(s):  
Daniela Livas ◽  
Marinka JH Almering ◽  
Jean-Marc Daran ◽  
Jack T Pronk ◽  
Juana M Gancedo
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Functional Protein ◽  
Transcriptional Responses ◽  
Kinase A

scholarly journals Regulation of maltose utilization in Saccharomyces cerevisiae by genes of the RAS/protein kinase A pathway 1

FEBS Letters ◽  
1997 ◽  
Vol 402 (2-3) ◽  
pp. 251-255 ◽  
Author(s):  
Valeria Wanke ◽  
Monica Vavassori ◽  
Johan M Thevelein ◽  
Paolo Tortora ◽  
Marco Vanoni
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Ras Protein ◽  
Maltose Utilization ◽  
Kinase A

scholarly journals p21-Activated Kinase 5 (Pak5) Localizes to Mitochondria and Inhibits Apoptosis by Phosphorylating BAD

2003 ◽  
Vol 23 (16) ◽  
pp. 5526-5539 ◽  
Author(s):  
Sophie Cotteret ◽  
Zahara M. Jaffer ◽  
Alexander Beeser ◽  
Jonathan Chernoff
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Kinase Activity ◽  
Independent Manner ◽  
Promote Neurite Outgrowth ◽  
P21 Activated Kinase ◽  
Kinase A ◽  
Apoptotic Cascade

ABSTRACT Pak5 is the most recently identified and least understood member of the p21-activated kinase (Pak) family. This kinase is known to promote neurite outgrowth in vitro, but its localization, substrates, and effects on cell survival have not been reported. We show here that Pak5 has unique properties that distinguish it from all other members of the Pak family. First, Pak5, unlike Pak1, cannot complement an STE20 mutation in Saccharomyces cerevisiae. Second, Pak5 binds to the GTPases Cdc42 and Rac, but these GTPases do not regulate Pak5 kinase activity, which is constitutive and stronger than any other Pak. Third, Pak5 prevents apoptosis induced by camptothecin and C2-ceramide by phosphorylating BAD on Ser-112 in a protein kinase A-independent manner and prevents the localization of BAD to mitochondria, thereby inhibiting the apoptotic cascade that leads to apoptosis. Finally, we show that Pak5 itself is constitutively localized to mitochondria, and that this localization is independent of kinase activity or Cdc42 binding. These features make Pak5 unique among the Pak family and suggest that it plays an important role in apoptosis through BAD phosphorylation.

Signal Transduction Dynamics of the Protein Kinase-A/Phosphofructokinase-2 System in Saccharomyces cerevisiae

2001 ◽  
Vol 3 (2) ◽  
pp. 163-172 ◽  
Author(s):  
Sam Vaseghi ◽  
Franz Macherhammer ◽  
Susanne Zibek ◽  
Matthias Reuss
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Signal Transduction ◽  
Protein Kinase ◽  
Protein Kinase A ◽  
Kinase A

Nutrient sensing systems for rapid activation of the protein kinase A pathway in yeast

2005 ◽  
Vol 33 (1) ◽  
pp. 253-256 ◽  
Author(s):  
J.M. Thevelein ◽  
R. Geladé ◽  
I. Holsbeeks ◽  
O. Lagatie ◽  
Y. Popova ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Protein Kinase A ◽  
Point Mutations ◽  
Nutrient Sensing ◽  
Amino Acid Permease ◽  
Yeast Saccharomyces Cerevisiae ◽  
Receptor System ◽  
Pka Pathway ◽  
Rapid Activation ◽  
Kinase A

The cAMP-protein kinase A (PKA) pathway in the yeast Saccharomyces cerevisiae controls a variety of properties that depend on the nutrient composition of the medium. High activity of the pathway occurs in the presence of rapidly fermented sugars like glucose or sucrose, but only as long as growth is maintained. Growth arrest of fermenting cells or growth on a respirative carbon source, like glycerol or ethanol, is associated with low activity of the PKA pathway. We have studied how different nutrients trigger rapid activation of the pathway. Glucose and sucrose activate cAMP synthesis through a G-protein-coupled receptor system, consisting of the GPCR Gpr1, the Gα protein Gpa2 and its RGS protein Rgs2. Glucose is also sensed intracellularly through its phosphorylation. Specific mutations in Gpr1 abolish glucose but not sucrose signalling. Activation of the PKA pathway by addition of a nitrogen source or phosphate to nitrogen- or phosphate-starved cells, respectively, is not mediated by an increase in cAMP. Activation by amino acids is triggered by the general amino acid permease Gap1, which functions as a transporter/receptor. Short truncation of the C-terminus results in constitutively activating alleles. Activation by ammonium uses the ammonium permeases Mep1 and Mep2 as receptor. Specific point mutations in Mep2 uncouple signalling from transport. Activation by phosphate is triggered a.o. by the Pho84 phosphate permease. Several mutations in Pho84 separating transport and signalling or triggering constitutive activation have been obtained.

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