Complex Formation, Phosphorylation, and Localization of Protein Kinase A of<i>Schizosaccharomyces pombe</i>upon Glucose Starvation

Gupta, Dipali Rani; Paul, Swapan Kumar; Oowatari, Yasuo; Matsuo, Yasuhiro; Kawamukai, Makoto

doi:10.1271/bbb.110125

Cited by 25 publications

(29 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both kinases phosphorylate Atg13 at different sites and inhibit, in a different way, the Atg1 complex [24], a key site that integrates different autophagic signals, as indicated also by the above reported effects of Snf1p and Pho85p [22]. In this regard, it is relevant that under glucose deprivation the regulatory and catalytic subunits form the PKA inactive complex [25], because this supports the inhibitory role of glucose on autophagy. Sch9, the closest yeast homologue of mammalian S6K1 and a substrate of TorC1, is also involved in nutrient sensing as an inhibitor of autophagy and in cooperation with PKA [26], although it is apparently less important.…”

Section: Regulation Of Autophagy By Glucose In Yeastmentioning

confidence: 97%

Regulation of Autophagy by Glucose in Mammalian Cells

Moruno

Pérez-Jiménez

Knecht

2012

Cells

View full text Add to dashboard Cite

Autophagy is an evolutionarily conserved process that contributes to maintain cell homeostasis. Although it is strongly regulated by many extracellular factors, induction of autophagy is mainly produced by starvation of nutrients. In mammalian cells, the regulation of autophagy by amino acids, and also by the hormone insulin, has been extensively investigated, but knowledge about the effects of other autophagy regulators, including another nutrient, glucose, is more limited. Here we will focus on the signalling pathways by which environmental glucose directly, i.e., independently of insulin and glucagon, regulates autophagy in mammalian cells, but we will also briefly mention some data in yeast. Although glucose deprivation mainly induces autophagy via AMPK activation and the subsequent inhibition of mTORC1, we will also comment other signalling pathways, as well as evidences indicating that, under certain conditions, autophagy can be activated by glucose. A better understanding on how glucose regulates autophagy not only will expand our basic knowledge of this important cell process, but it will be also relevant to understand common human disorders, such as cancer and diabetes, in which glucose levels play an important role.

show abstract

Section: Regulation Of Autophagy By Glucose In Yeastmentioning

confidence: 97%

Regulation of Autophagy by Glucose in Mammalian Cells

Moruno

Pérez-Jiménez

Knecht

2012

Cells

View full text Add to dashboard Cite

show abstract

“…We therefore examined Pka1, a kinase regulated by cAMP. Previous studies reported that Pka1 undergoes inhibitory phosphorylation when cells were starved for glucose for several hours or more (Gupta et al, 2011;McInnis et al, 2010). As shown in Fig.…”

Section: Glucose/camp Signaling Regulates Tf2s Expressionmentioning

confidence: 73%

The RHEB–mTOR axis regulates expression of Tf2 transposons in fission yeast

Nakase

Matsumoto

2018

Journal of Cell Science

View full text Add to dashboard Cite

The human TSC2 gene, mutations in which predispose individuals to the disease tuberous sclerosis complex (TSC), encodes a GTPaseactivating protein for the GTPase RHEB. Loss of TSC2 results in constitutive activation of RHEB and its target mammalian target of rapamycin (mTOR). We have previously reported that fission yeast (Schizosaccharomyces pombe) Tf2 retrotransposons (hereafter Tf2s) are abnormally induced upon nitrogen starvation in cells lacking the tsc2 + gene (Δtsc2), a homolog of the human TSC2 gene, and in cells with a dominant-active mutation in the fission yeast RHEB GTPase (rhb1-DA4). We report here that induction of Tf2s in these mutants is suppressed upon overexpression of the cgs2 + gene, which encodes a cAMP-specific phosphodiesterase, or upon deletion of components in the glucose/cAMP signaling pathway, namely Cyr1, Pka1, Tor1 and the stress-activated transcription factor Atf1. The results suggest that the glucose/cAMP signaling pathway is downregulated when cells are starved for nitrogen. We also show that Tf2 proteins are degraded via autophagy, which is under control of Tor2, a homolog of human mTOR. It appears that failure in the two processes, downregulation of the glucose/cAMP signaling pathway and induction of autophagy, allows abnormal induction of Tf2s upon nitrogen starvation in Δtsc2 and rhb1-DA4 cells.

show abstract

“…14,29−33) The strains lacking functional components of the cAMP/PKA pathway (cyr1Δ and pka1Δ) were sensitive to 1.5 M KCl but not to 0.3 M NaCl and 2 M sorbitol, as previously shown. 10,13,14,34) The cyr1Δ and pka1Δ strains were found to exhibit a 0.3 M CaCl 2 -sensitive phenotype (Fig. 1).…”

Section: Loss Of Functional Pka Results In Cacl 2 -Sensitive Phenotypementioning

confidence: 98%

“…12) The nuclear-cytoplasmic redistribution of both proteins is triggered by glucose-limitation, KCl stress, and in stationary-phase growth 12) ; and Pka1 physically interacts with Cgs1 under glucoselimited conditions and not under glucose-rich conditions. 13) Pka1 is phosphorylated at threonine 356 under glucose-limited conditions 13,14) and Pka1 phosphorylation is elevated in cyr1Δ mutants and is promoted by KCl. 15) In glucose-rich medium, the non-phosphorylated form of mutant Pka1 (T356A) localizes evenly between the cytoplasm and the nucleus, while the phosphomimetic mutant Pka1 (T356D) concentrates only in the nucleus.…”

mentioning

confidence: 99%

cAMP-dependent protein kinase involves calcium tolerance through the regulation of Prz1 inSchizosaccharomyces pombe

Matsuo

Kawamukai

2017

Bioscience, Biotechnology, and Biochemistry

Self Cite

View full text Add to dashboard Cite

The cAMP-dependent protein kinase Pka1 is known as a regulator of glycogenesis, meiosis, and stress responses in Schizosaccharomyces pombe. We demonstrated that Pka1 is responsible for calcium tolerance. Loss of functional components of the PKA pathway such as Git3, Gpa2, Cyr1, and Pka1 yields a CaCl-sensitive phenotype, while loss of Cgs1, a regulatory subunit of PKA, results in CaCl tolerance. Cytoplasmic distribution of Cgs1 and Pka1 is increased by the addition of CaCl, suggesting that CaCl induces dissociation of Cgs1 and Pka1. The expression of Prz1, a transcriptional regulator in calcium homeostasis, is elevated in a pka1∆ strain and in a wild type strain under glucose-limited conditions. Accordingly, higher expression of Prz1 in the wild type strain results in a CaCl-sensitive phenotype. These findings suggest that Pka1 is essential for tolerance to exogenous CaCl, probably because the expression level of Prz1 needs to be properly regulated by Pka1.

show abstract

Complex Formation, Phosphorylation, and Localization of Protein Kinase A ofSchizosaccharomyces pombeupon Glucose Starvation

Cited by 25 publications

References 39 publications

Regulation of Autophagy by Glucose in Mammalian Cells

Regulation of Autophagy by Glucose in Mammalian Cells

The RHEB–mTOR axis regulates expression of Tf2 transposons in fission yeast

cAMP-dependent protein kinase involves calcium tolerance through the regulation of Prz1 inSchizosaccharomyces pombe

Contact Info

Product

Resources

About