1
|
Wang D, Zeng N, Li C, Li Z, Zhang N, Li B. Fungal biofilm formation and its regulatory mechanism. Heliyon 2024; 10:e32766. [PMID: 38988529 PMCID: PMC11233959 DOI: 10.1016/j.heliyon.2024.e32766] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 06/07/2024] [Accepted: 06/08/2024] [Indexed: 07/12/2024] Open
Abstract
Fungal biofilm is a microbial community composed of fungal cells and extracellular polymeric substances (EPS). In recent years, fungal biofilms have played an increasingly important role in many fields. However, there are few studies on fungal biofilms and their related applications and development are still far from enough. Therefore, this review summarizes the composition and function of EPS in fungal biofilms, and improves and refines the formation process of fungal biofilms according to the latest viewpoints. Moreover, based on the study of Saccharomyces cerevisiae and Candida albicans, this review summarizes the gene regulation network of fungal biofilm synthesis, which is crucial for systematically understanding the molecular mechanism of fungal biofilm formation. It is of great significance to further develop effective methods at the molecular level to control harmful biofilms or enhance and regulate the formation of beneficial biofilms. Finally, the quorum sensing factors and mixed biofilms formed by fungi in the current research of fungal biofilms are summarized. These results will help to deepen the understanding of the formation process and internal regulation mechanism of fungal biofilm, provide reference for the study of EPS composition and structure, formation, regulation, group behavior and mixed biofilm formation of other fungal biofilms, and provide strategies and theoretical basis for the control, development and utilization of fungal biofilms.
Collapse
Affiliation(s)
- Dandan Wang
- College of Land and Environment, Shenyang Agricultural University, Shenyang, 110866, PR China
| | - Nan Zeng
- College of Land and Environment, Shenyang Agricultural University, Shenyang, 110866, PR China
| | - Chunji Li
- Innovative Institute for Plant Health, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, PR China
- Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China, Ministry of Agriculture and Rural Affairs, Guangzhou, 510225, PR China
- College of Agriculture and Biology, Zhongkai University of Agriculture and Engineering, Guangzhou, 510225, PR China
| | - Zijing Li
- College of Food Science, Shenyang Agricultural University, Shenyang, 110866, PR China
| | - Ning Zhang
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866, PR China
| | - Bingxue Li
- College of Land and Environment, Shenyang Agricultural University, Shenyang, 110866, PR China
| |
Collapse
|
2
|
Lucca C, Ferrari E, Shubassi G, Ajazi A, Choudhary R, Bruhn C, Matafora V, Bachi A, Foiani M. Sch9 S6K controls DNA repair and DNA damage response efficiency in aging cells. Cell Rep 2024; 43:114281. [PMID: 38805395 DOI: 10.1016/j.celrep.2024.114281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 04/10/2024] [Accepted: 05/10/2024] [Indexed: 05/30/2024] Open
Abstract
Survival from UV-induced DNA lesions relies on nucleotide excision repair (NER) and the Mec1ATR DNA damage response (DDR). We study DDR and NER in aging cells and find that old cells struggle to repair DNA and activate Mec1ATR. We employ pharmacological and genetic approaches to rescue DDR and NER during aging. Conditions activating Snf1AMPK rescue DDR functionality, but not NER, while inhibition of the TORC1-Sch9S6K axis restores NER and enhances DDR by tuning PP2A activity, specifically in aging cells. Age-related repair deficiency depends on Snf1AMPK-mediated phosphorylation of Sch9S6K on Ser160 and Ser163. PP2A activity in old cells is detrimental for DDR and influences NER by modulating Snf1AMPK and Sch9S6K. Hence, the DDR and repair pathways in aging cells are influenced by the metabolic tuning of opposing AMPK and TORC1 networks and by PP2A activity. Specific Sch9S6K phospho-isoforms control DDR and NER efficiency, specifically during aging.
Collapse
Affiliation(s)
- Chiara Lucca
- IFOM ETS - The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Elisa Ferrari
- IFOM ETS - The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy.
| | - Ghadeer Shubassi
- AtomVie Global Radiopharma Inc., 1280 Main Street W NRB-A316, Hamilton, ON L8S-4K1, Canada
| | - Arta Ajazi
- IFOM ETS - The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Ramveer Choudhary
- IFOM ETS - The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Christopher Bruhn
- IFOM ETS - The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Vittoria Matafora
- IFOM ETS - The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Angela Bachi
- IFOM ETS - The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy
| | - Marco Foiani
- IFOM ETS - The AIRC Institute of Molecular Oncology, Via Adamello 16, 20139 Milan, Italy; Istituto di Genetica Molecolare, CNR, Pavia, Italy.
| |
Collapse
|
3
|
Wang Y, Ruan L, Zhu J, Zhang X, Chang ACC, Tomaszewski A, Li R. Metabolic regulation of misfolded protein import into mitochondria. eLife 2024; 12:RP87518. [PMID: 38900507 PMCID: PMC11189628 DOI: 10.7554/elife.87518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024] Open
Abstract
Mitochondria are the cellular energy hub and central target of metabolic regulation. Mitochondria also facilitate proteostasis through pathways such as the 'mitochondria as guardian in cytosol' (MAGIC) whereby cytosolic misfolded proteins (MPs) are imported into and degraded inside mitochondria. In this study, a genome-wide screen in Saccharomyces cerevisiae uncovered that Snf1, the yeast AMP-activated protein kinase (AMPK), inhibits the import of MPs into mitochondria while promoting mitochondrial biogenesis under glucose starvation. We show that this inhibition requires a downstream transcription factor regulating mitochondrial gene expression and is likely to be conferred through substrate competition and mitochondrial import channel selectivity. We further show that Snf1/AMPK activation protects mitochondrial fitness in yeast and human cells under stress induced by MPs such as those associated with neurodegenerative diseases.
Collapse
Affiliation(s)
- Yuhao Wang
- Center for Cell Dynamics and Department of Cell Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
- Biochemistry, Cellular and Molecular Biology (BCMB) Graduate Program, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Linhao Ruan
- Center for Cell Dynamics and Department of Cell Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Jin Zhu
- Mechanobiology Institute and Department of Biological Sciences, National University of SingaporeSingaporeSingapore
| | - Xi Zhang
- Center for Cell Dynamics and Department of Cell Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Alexander Chih-Chieh Chang
- Center for Cell Dynamics and Department of Cell Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins UniversityBaltimoreUnited States
| | - Alexis Tomaszewski
- Center for Cell Dynamics and Department of Cell Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
- Biochemistry, Cellular and Molecular Biology (BCMB) Graduate Program, Johns Hopkins University School of MedicineBaltimoreUnited States
| | - Rong Li
- Center for Cell Dynamics and Department of Cell Biology, Johns Hopkins University School of MedicineBaltimoreUnited States
- Mechanobiology Institute and Department of Biological Sciences, National University of SingaporeSingaporeSingapore
- Department of Chemical and Biomolecular Engineering, Whiting School of Engineering, Johns Hopkins UniversityBaltimoreUnited States
| |
Collapse
|
4
|
Sunder S, Bauman JS, Decker SJ, Lifton AR, Kumar A. The yeast AMP-activated protein kinase Snf1 phosphorylates the inositol polyphosphate kinase Kcs1. J Biol Chem 2024; 300:105657. [PMID: 38224949 PMCID: PMC10851228 DOI: 10.1016/j.jbc.2024.105657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Revised: 12/31/2023] [Accepted: 01/08/2024] [Indexed: 01/17/2024] Open
Abstract
The yeast Snf1/AMP-activated kinase (AMPK) maintains energy homeostasis, controlling metabolic processes and glucose derepression in response to nutrient levels and environmental cues. Under conditions of nitrogen or glucose limitation, Snf1 regulates pseudohyphal growth, a morphological transition characterized by the formation of extended multicellular filaments. During pseudohyphal growth, Snf1 is required for wild-type levels of inositol polyphosphate (InsP), soluble phosphorylated species of the six-carbon cyclitol inositol that function as conserved metabolic second messengers. InsP levels are established through the activity of a family of inositol kinases, including the yeast inositol polyphosphate kinase Kcs1, which principally generates pyrophosphorylated InsP7. Here, we report that Snf1 regulates Kcs1, affecting Kcs1 phosphorylation and inositol kinase activity. A snf1 kinase-defective mutant exhibits decreased Kcs1 phosphorylation, and Kcs1 is phosphorylated in vivo at Ser residues 537 and 646 during pseudohyphal growth. By in vitro analysis, Snf1 directly phosphorylates Kcs1, predominantly at amino acids 537 and 646. A yeast strain carrying kcs1 encoding Ser-to-Ala point mutations at these residues (kcs1-S537A,S646A) shows elevated levels of pyrophosphorylated InsP7, comparable to InsP7 levels observed upon deletion of SNF1. The kcs1-S537A,S646A mutant exhibits decreased pseudohyphal growth, invasive growth, and cell elongation. Transcriptional profiling indicates extensive perturbation of metabolic pathways in kcs1-S537A,S646A. Growth of kcs1-S537A,S646A is affected on medium containing sucrose and antimycin A, consistent with decreased Snf1p signaling. This work identifies Snf1 phosphorylation of Kcs1, collectively highlighting the interconnectedness of AMPK activity and InsP signaling in coordinating nutrient availability, energy homoeostasis, and cell growth.
Collapse
Affiliation(s)
- Sham Sunder
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Joshua S Bauman
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Stuart J Decker
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Alexandra R Lifton
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Anuj Kumar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA.
| |
Collapse
|
5
|
Simpson-Lavy K, Kupiec M. Glucose Inhibits Yeast AMPK (Snf1) by Three Independent Mechanisms. BIOLOGY 2023; 12:1007. [PMID: 37508436 PMCID: PMC10376661 DOI: 10.3390/biology12071007] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/13/2023] [Accepted: 07/13/2023] [Indexed: 07/30/2023]
Abstract
Snf1, the fungal homologue of mammalian AMP-dependent kinase (AMPK), is a key protein kinase coordinating the response of cells to a shortage of glucose. In fungi, the response is to activate respiratory gene expression and metabolism. The major regulation of Snf1 activity has been extensively investigated: In the absence of glucose, it becomes activated by phosphorylation of its threonine at position 210. This modification can be erased by phosphatases when glucose is restored. In the past decade, two additional independent mechanisms of Snf1 regulation have been elucidated. In response to glucose (or, surprisingly, also to DNA damage), Snf1 is SUMOylated by Mms21 at lysine 549. This inactivates Snf1 and leads to Snf1 degradation. More recently, glucose-induced proton export has been found to result in Snf1 inhibition via a polyhistidine tract (13 consecutive histidine residues) at the N-terminus of the Snf1 protein. Interestingly, the polyhistidine tract plays also a central role in the response to iron scarcity. This review will present some of the glucose-sensing mechanisms of S. cerevisiae, how they interact, and how their interplay results in Snf1 inhibition by three different, and independent, mechanisms.
Collapse
Affiliation(s)
- Kobi Simpson-Lavy
- The Shmunis School of Biomedicine & Cancer Research, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| | - Martin Kupiec
- The Shmunis School of Biomedicine & Cancer Research, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel
| |
Collapse
|
6
|
Lesko MA, Chandrashekarappa DG, Jordahl EM, Oppenheimer KG, Bowman RW, Shang C, Durrant JD, Schmidt MC, O’Donnell AF. Changing course: Glucose starvation drives nuclear accumulation of Hexokinase 2 in S. cerevisiae. PLoS Genet 2023; 19:e1010745. [PMID: 37196001 PMCID: PMC10228819 DOI: 10.1371/journal.pgen.1010745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 05/30/2023] [Accepted: 04/14/2023] [Indexed: 05/19/2023] Open
Abstract
Glucose is the preferred carbon source for most eukaryotes, and the first step in its metabolism is phosphorylation to glucose-6-phosphate. This reaction is catalyzed by hexokinases or glucokinases. The yeast Saccharomyces cerevisiae encodes three such enzymes, Hxk1, Hxk2, and Glk1. In yeast and mammals, some isoforms of this enzyme are found in the nucleus, suggesting a possible moonlighting function beyond glucose phosphorylation. In contrast to mammalian hexokinases, yeast Hxk2 has been proposed to shuttle into the nucleus in glucose-replete conditions, where it reportedly moonlights as part of a glucose-repressive transcriptional complex. To achieve its role in glucose repression, Hxk2 reportedly binds the Mig1 transcriptional repressor, is dephosphorylated at serine 15 and requires an N-terminal nuclear localization sequence (NLS). We used high-resolution, quantitative, fluorescent microscopy of live cells to determine the conditions, residues, and regulatory proteins required for Hxk2 nuclear localization. Countering previous yeast studies, we find that Hxk2 is largely excluded from the nucleus under glucose-replete conditions but is retained in the nucleus under glucose-limiting conditions. We find that the Hxk2 N-terminus does not contain an NLS but instead is necessary for nuclear exclusion and regulating multimerization. Amino acid substitutions of the phosphorylated residue, serine 15, disrupt Hxk2 dimerization but have no effect on its glucose-regulated nuclear localization. Alanine substation at nearby lysine 13 affects dimerization and maintenance of nuclear exclusion in glucose-replete conditions. Modeling and simulation provide insight into the molecular mechanisms of this regulation. In contrast to earlier studies, we find that the transcriptional repressor Mig1 and the protein kinase Snf1 have little effect on Hxk2 localization. Instead, the protein kinase Tda1 regulates Hxk2 localization. RNAseq analyses of the yeast transcriptome dispels the idea that Hxk2 moonlights as a transcriptional regulator of glucose repression, demonstrating that Hxk2 has a negligible role in transcriptional regulation in both glucose-replete and limiting conditions. Our studies define a new model of cis- and trans-acting regulators of Hxk2 dimerization and nuclear localization. Based on our data, the nuclear translocation of Hxk2 in yeast occurs in glucose starvation conditions, which aligns well with the nuclear regulation of mammalian orthologs. Our results lay the foundation for future studies of Hxk2 nuclear activity.
Collapse
Affiliation(s)
- Mitchell A. Lesko
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Dakshayini G. Chandrashekarappa
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Eric M. Jordahl
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Katherine G. Oppenheimer
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Ray W. Bowman
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Chaowei Shang
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Jacob D. Durrant
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Martin C. Schmidt
- Department of Microbiology and Molecular Genetics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Allyson F. O’Donnell
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| |
Collapse
|
7
|
Caligaris M, Nicastro R, Hu Z, Tripodi F, Hummel JE, Pillet B, Deprez MA, Winderickx J, Rospert S, Coccetti P, Dengjel J, De Virgilio C. Snf1/AMPK fine-tunes TORC1 signaling in response to glucose starvation. eLife 2023; 12:84319. [PMID: 36749016 PMCID: PMC9937656 DOI: 10.7554/elife.84319] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Accepted: 02/06/2023] [Indexed: 02/08/2023] Open
Abstract
The AMP-activated protein kinase (AMPK) and the target of rapamycin complex 1 (TORC1) are central kinase modules of two opposing signaling pathways that control eukaryotic cell growth and metabolism in response to the availability of energy and nutrients. Accordingly, energy depletion activates AMPK to inhibit growth, while nutrients and high energy levels activate TORC1 to promote growth. Both in mammals and lower eukaryotes such as yeast, the AMPK and TORC1 pathways are wired to each other at different levels, which ensures homeostatic control of growth and metabolism. In this context, a previous study (Hughes Hallett et al., 2015) reported that AMPK in yeast, that is Snf1, prevents the transient TORC1 reactivation during the early phase following acute glucose starvation, but the underlying mechanism has remained elusive. Using a combination of unbiased mass spectrometry (MS)-based phosphoproteomics, genetic, biochemical, and physiological experiments, we show here that Snf1 temporally maintains TORC1 inactive in glucose-starved cells primarily through the TORC1-regulatory protein Pib2. Our data, therefore, extend the function of Pib2 to a hub that integrates both glucose and, as reported earlier, glutamine signals to control TORC1. We further demonstrate that Snf1 phosphorylates the TORC1 effector kinase Sch9 within its N-terminal region and thereby antagonizes the phosphorylation of a C-terminal TORC1-target residue within Sch9 itself that is critical for its activity. The consequences of Snf1-mediated phosphorylation of Pib2 and Sch9 are physiologically additive and sufficient to explain the role of Snf1 in short-term inhibition of TORC1 in acutely glucose-starved cells.
Collapse
Affiliation(s)
- Marco Caligaris
- Department of Biology, University of FribourgFribourgSwitzerland
| | | | - Zehan Hu
- Department of Biology, University of FribourgFribourgSwitzerland
| | - Farida Tripodi
- Department of Biotechnology and Biosciences, University of Milano-BicoccaMilanoItaly
| | - Johannes Erwin Hummel
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of FreiburgFreiburgGermany
| | - Benjamin Pillet
- Department of Biology, University of FribourgFribourgSwitzerland
| | | | | | - Sabine Rospert
- Institute of Biochemistry and Molecular Biology, Faculty of Medicine, University of FreiburgFreiburgGermany,Signalling Research Centres BIOSS and CIBSS, University of FreiburgFreiburgGermany
| | - Paola Coccetti
- Department of Biotechnology and Biosciences, University of Milano-BicoccaMilanoItaly
| | - Jörn Dengjel
- Department of Biology, University of FribourgFribourgSwitzerland
| | | |
Collapse
|
8
|
Liu Z, Li B, Song L, Zhang H. Pillar[ n]arene-calix[ m]arene hybrid macrocyclic structures. RSC Adv 2022; 12:28185-28195. [PMID: 36320255 PMCID: PMC9528731 DOI: 10.1039/d2ra05118d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Accepted: 09/19/2022] [Indexed: 06/16/2023] Open
Abstract
To reserve planar chirality, enhance molecular recognition, and build advanced self-assemblies, hybrid macrocyclic hosts containing rigid pillar[n]arene and flexible calix[m]arene were designed, prepared and investigated for interesting applications. This review summarizes and discusses different synthetic strategies for constructing hybrid macrocyclic structures. Pillar[n]arene dimer with rigid aromatic double bridges provided the possibility of introducing calix[m]arene cavities, where the planar chirality was reserved in the structure of pillararene. The capacity for molecular recognition was enhanced by hybrid macrocyclic cavities. Interestingly, the obtained pillar[n]arene-calix[m]arene could self-assemble into "channels" and "honeycomb" in both the solid state and solution phase as well as donate the molecular architecture as the wheel for the formation of mechanically interlocked molecules, such as rotaxane. In addition, the pillar[n]arene and calix[m]arene could also be coupled together to produce pillar[n]arene embeded 1,3-alternate and cone conformational calix[m]arene derivatives, which could catalyze the oxidative polymerization of aniline in aqueous solutions. Except for building hybrid cyclophanes by covalent bonds, weak supramolecular interactions were used to prepare pillar[n]arene-calix[m]arene analogous composites with other pillar-like pillar[n]pyridiniums and calix-like calix[m]pyrroles, exhibiting reasonable performances in enhancing molecular recognition and trapping solvent molecules.
Collapse
Affiliation(s)
- Zhaona Liu
- Medical School, Xi'an Peihua University Xi'an 710125 Shaanxi China
| | - Bing Li
- School of Chemical Engineering and Technology, Xi'an Jiaotong University Xi'an Shaanxi 710049 China
| | - Leqian Song
- School of Chemical Engineering and Technology, Xi'an Jiaotong University Xi'an Shaanxi 710049 China
| | - Huacheng Zhang
- School of Chemical Engineering and Technology, Xi'an Jiaotong University Xi'an Shaanxi 710049 China
| |
Collapse
|
9
|
Chen H, Chai X, Wang Y, Liu J, Zhou G, Wei P, Song Y, Ma L. The multiple effects of REG1 deletion and SNF1 overexpression improved the production of S-adenosyl-L-methionine in Saccharomyces cerevisiae. Microb Cell Fact 2022; 21:174. [PMID: 36030199 PMCID: PMC9419380 DOI: 10.1186/s12934-022-01900-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 08/21/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Saccharomyces cerevisiae is often used as a cell factory for the production of S-adenosyl-L-methionine (SAM) for diverse pharmaceutical applications. However, SAM production by S. cerevisiae is negatively influenced by glucose repression, which is regulated by a serine/threonine kinase SNF1 complex. Here, a strategy of alleviating glucose repression by deleting REG1 (encodes the regulatory subunit of protein phosphatase 1) and overexpressing SNF1 (encodes the catalytic subunit of the SNF1 complex) was applied to improve SAM production in S. cerevisiae. SAM production, growth conditions, glucose consumption, ethanol accumulation, lifespan, glycolysis and amino acid metabolism were analyzed in the mutant strains. RESULTS The results showed that the multiple effects of REG1 deletion and/or SNF1 overexpression exhibited a great potential for improving the SAM production in yeast. Enhanced the expression levels of genes involved in glucose transport and glycolysis, which improved the glucose utilization and then elevated the levels of glycolytic intermediates. The expression levels of ACS1 (encoding acetyl-CoA synthase I) and ALD6 (encoding aldehyde dehydrogenase), and the activity of alcohol dehydrogenase II (ADH2) were enhanced especially in the presence of excessive glucose levels, which probably promoted the conversion of ethanol in fermentation broth into acetyl-CoA. The gene expressions involved in sulfur-containing amino acids were also enhanced for the precursor amino acid biosynthesis. In addition, the lifespan of yeast was extended by REG1 deletion and/or SNF1 overexpression. As expected, the final SAM yield of the mutant YREG1ΔPSNF1 reached 8.28 g/L in a 10-L fermenter, which was 51.6% higher than the yield of the parent strain S. cerevisiae CGMCC 2842. CONCLUSION This study showed that the multiple effects of REG1 deletion and SNF1 overexpression improved SAM production in S. cerevisiae, providing new insight into the application of the SNF1 complex to abolish glucose repression and redirect carbon flux to nonethanol products in S. cerevisiae.
Collapse
Affiliation(s)
- Hailong Chen
- Jiangsu Key Laboratory of Chiral Pharmaceuticals Biosynthesis, College of Pharmacy and Chemistry & Chemical Engineering, Taizhou University, 93 Ji Chuan Road, 225300, Taizhou, Jiangsu, People's Republic of China
| | - Xiaoqin Chai
- Jiangsu Key Laboratory of Chiral Pharmaceuticals Biosynthesis, College of Pharmacy and Chemistry & Chemical Engineering, Taizhou University, 93 Ji Chuan Road, 225300, Taizhou, Jiangsu, People's Republic of China
| | - Yan Wang
- Jiangsu Key Laboratory of Chiral Pharmaceuticals Biosynthesis, College of Pharmacy and Chemistry & Chemical Engineering, Taizhou University, 93 Ji Chuan Road, 225300, Taizhou, Jiangsu, People's Republic of China
| | - Jing Liu
- Jiangsu Key Laboratory of Chiral Pharmaceuticals Biosynthesis, College of Pharmacy and Chemistry & Chemical Engineering, Taizhou University, 93 Ji Chuan Road, 225300, Taizhou, Jiangsu, People's Republic of China
| | - Guohai Zhou
- Jiangsu Key Laboratory of Chiral Pharmaceuticals Biosynthesis, College of Pharmacy and Chemistry & Chemical Engineering, Taizhou University, 93 Ji Chuan Road, 225300, Taizhou, Jiangsu, People's Republic of China
| | - Pinghe Wei
- Jiangsu Key Laboratory of Chiral Pharmaceuticals Biosynthesis, College of Pharmacy and Chemistry & Chemical Engineering, Taizhou University, 93 Ji Chuan Road, 225300, Taizhou, Jiangsu, People's Republic of China
| | - Yuhe Song
- Jiangsu Key Laboratory of Chiral Pharmaceuticals Biosynthesis, College of Pharmacy and Chemistry & Chemical Engineering, Taizhou University, 93 Ji Chuan Road, 225300, Taizhou, Jiangsu, People's Republic of China.
| | - Lingman Ma
- School of Life Science and Technology, China Pharmaceutical University, 211198, Nanjing, Jiangsu, People's Republic of China.
| |
Collapse
|
10
|
Farre JC, Carolino K, Devanneaux L, Subramani S. OXPHOS deficiencies affect peroxisome proliferation by downregulating genes controlled by the SNF1 signaling pathway. eLife 2022; 11:e75143. [PMID: 35467529 PMCID: PMC9094750 DOI: 10.7554/elife.75143] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
How environmental cues influence peroxisome proliferation, particularly through organelles, remains largely unknown. Yeast peroxisomes metabolize fatty acids (FA), and methylotrophic yeasts also metabolize methanol. NADH and acetyl-CoA, produced by these pathways enter mitochondria for ATP production and for anabolic reactions. During the metabolism of FA and/or methanol, the mitochondrial oxidative phosphorylation (OXPHOS) pathway accepts NADH for ATP production and maintains cellular redox balance. Remarkably, peroxisome proliferation in Pichia pastoris was abolished in NADH-shuttling- and OXPHOS mutants affecting complex I or III, or by the mitochondrial uncoupler, 2,4-dinitrophenol (DNP), indicating ATP depletion causes the phenotype. We show that mitochondrial OXPHOS deficiency inhibits expression of several peroxisomal proteins implicated in FA and methanol metabolism, as well as in peroxisome division and proliferation. These genes are regulated by the Snf1 complex (SNF1), a pathway generally activated by a high AMP/ATP ratio. In OXPHOS mutants, Snf1 is activated by phosphorylation, but Gal83, its interacting subunit, fails to translocate to the nucleus. Phenotypic defects in peroxisome proliferation observed in the OXPHOS mutants, and phenocopied by the Δgal83 mutant, were rescued by deletion of three transcriptional repressor genes (MIG1, MIG2, and NRG1) controlled by SNF1 signaling. Our results are interpreted in terms of a mechanism by which peroxisomal and mitochondrial proteins and/or metabolites influence redox and energy metabolism, while also influencing peroxisome biogenesis and proliferation, thereby exemplifying interorganellar communication and interplay involving peroxisomes, mitochondria, cytosol, and the nucleus. We discuss the physiological relevance of this work in the context of human OXPHOS deficiencies.
Collapse
Affiliation(s)
- Jean-Claude Farre
- Section of Molecular Biology, Division of Biological Sciences, University of California, San DiegoLa JollaUnited States
| | - Krypton Carolino
- Section of Molecular Biology, Division of Biological Sciences, University of California, San DiegoLa JollaUnited States
| | - Lou Devanneaux
- Section of Molecular Biology, Division of Biological Sciences, University of California, San DiegoLa JollaUnited States
| | - Suresh Subramani
- Section of Molecular Biology, Division of Biological Sciences, University of California, San DiegoLa JollaUnited States
| |
Collapse
|
11
|
Casamayor A, Ariño J. When Phosphatases Go Mad: The Molecular Basis for Toxicity of Yeast Ppz1. Int J Mol Sci 2022; 23:ijms23084304. [PMID: 35457140 PMCID: PMC9029398 DOI: 10.3390/ijms23084304] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 04/04/2022] [Accepted: 04/08/2022] [Indexed: 02/04/2023] Open
Abstract
The fact that overexpression of the yeast Ser/Thr protein phosphatase Ppz1 induces a dramatic halt in cell proliferation was known long ago, but only work in the last few years has provided insight into the molecular basis for this toxicity. Overexpression of Ppz1 causes abundant changes in gene expression and modifies the phosphorylation state of more than 150 proteins, including key signaling protein kinases such as Hog1 or Snf1. Diverse cellular processes are altered: halt in translation, failure to properly adapt to low glucose supply, acidification of the cytosol, or depletion of intracellular potassium content are a few examples. Therefore, the toxicity derived from an excess of Ppz1 appears to be multifactorial, the characteristic cell growth blockage thus arising from the combination of various altered processes. Notably, overexpression of the Ppz1 regulatory subunit Hal3 fully counteracts the toxic effects of the phosphatase, and this process involves intracellular relocation of the phosphatase to internal membranes.
Collapse
|
12
|
Laidlaw KME, Paine KM, Bisinski DD, Calder G, Hogg K, Ahmed S, James S, O’Toole PJ, MacDonald C. Endosomal cargo recycling mediated by Gpa1 and phosphatidylinositol 3-kinase is inhibited by glucose starvation. Mol Biol Cell 2022; 33:ar31. [PMID: 35080991 PMCID: PMC9250360 DOI: 10.1091/mbc.e21-04-0163] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Cell surface protein trafficking is regulated in response to nutrient availability, with multiple pathways directing surface membrane proteins to the lysosome for degradation in response to suboptimal extracellular nutrients. Internalized protein and lipid cargoes recycle back to the surface efficiently in glucose-replete conditions, but this trafficking is attenuated following glucose starvation. We find that cells with either reduced or hyperactive phosphatidylinositol 3-kinase (PI3K) activity are defective for endosome to surface recycling. Furthermore, we find that the yeast Gα subunit Gpa1, an endosomal PI3K effector, is required for surface recycling of cargoes. Following glucose starvation, mRNA and protein levels of a distinct Gα subunit Gpa2 are elevated following nuclear translocation of Mig1, which inhibits recycling of various cargoes. As Gpa1 and Gpa2 interact at the surface where Gpa2 concentrates during glucose starvation, we propose that this disrupts PI3K activity required for recycling, potentially diverting Gpa1 to the surface and interfering with its endosomal role in recycling. In support of this model, glucose starvation and overexpression of Gpa2 alter PI3K endosomal phosphoinositide production. Glucose deprivation therefore triggers a survival mechanism to increase retention of surface cargoes in endosomes and promote their lysosomal degradation.
Collapse
Affiliation(s)
| | | | | | - Grant Calder
- Bioscience Technology Facility, Department of Biology, University of York, YO10 5DD York, UK
| | - Karen Hogg
- Bioscience Technology Facility, Department of Biology, University of York, YO10 5DD York, UK
| | - Sophia Ahmed
- Bioscience Technology Facility, Department of Biology, University of York, YO10 5DD York, UK
| | - Sally James
- Bioscience Technology Facility, Department of Biology, University of York, YO10 5DD York, UK
| | - Peter J. O’Toole
- Bioscience Technology Facility, Department of Biology, University of York, YO10 5DD York, UK
| | - Chris MacDonald
- York Biomedical Research Institute and Department of Biology and,*Address correspondence to: Chris MacDonald ()
| |
Collapse
|
13
|
Österberg L, Domenzain I, Münch J, Nielsen J, Hohmann S, Cvijovic M. A novel yeast hybrid modeling framework integrating Boolean and enzyme-constrained networks enables exploration of the interplay between signaling and metabolism. PLoS Comput Biol 2021; 17:e1008891. [PMID: 33836000 PMCID: PMC8059808 DOI: 10.1371/journal.pcbi.1008891] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 04/21/2021] [Accepted: 03/18/2021] [Indexed: 12/11/2022] Open
Abstract
The interplay between nutrient-induced signaling and metabolism plays an important role in maintaining homeostasis and its malfunction has been implicated in many different human diseases such as obesity, type 2 diabetes, cancer, and neurological disorders. Therefore, unraveling the role of nutrients as signaling molecules and metabolites together with their interconnectivity may provide a deeper understanding of how these conditions occur. Both signaling and metabolism have been extensively studied using various systems biology approaches. However, they are mainly studied individually and in addition, current models lack both the complexity of the dynamics and the effects of the crosstalk in the signaling system. To gain a better understanding of the interconnectivity between nutrient signaling and metabolism in yeast cells, we developed a hybrid model, combining a Boolean module, describing the main pathways of glucose and nitrogen signaling, and an enzyme-constrained model accounting for the central carbon metabolism of Saccharomyces cerevisiae, using a regulatory network as a link. The resulting hybrid model was able to capture a diverse utalization of isoenzymes and to our knowledge outperforms constraint-based models in the prediction of individual enzymes for both respiratory and mixed metabolism. The model showed that during fermentation, enzyme utilization has a major contribution in governing protein allocation, while in low glucose conditions robustness and control are prioritized. In addition, the model was capable of reproducing the regulatory effects that are associated with the Crabtree effect and glucose repression, as well as regulatory effects associated with lifespan increase during caloric restriction. Overall, we show that our hybrid model provides a comprehensive framework for the study of the non-trivial effects of the interplay between signaling and metabolism, suggesting connections between the Snf1 signaling pathways and processes that have been related to chronological lifespan of yeast cells.
Collapse
Affiliation(s)
- Linnea Österberg
- Department of Mathematical Sciences, University of Gothenburg, Gothenburg, Sweden
- Department of Mathematical Sciences, Chalmers University of Technology, Gothenburg, Sweden
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Iván Domenzain
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Gothenburg, Sweden
| | - Julia Münch
- Department of Mathematical Sciences, University of Gothenburg, Gothenburg, Sweden
- Department of Mathematical Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, Gothenburg, Sweden
- BioInnovation Institute, Copenhagen, Denmark
| | - Stefan Hohmann
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - Marija Cvijovic
- Department of Mathematical Sciences, University of Gothenburg, Gothenburg, Sweden
- Department of Mathematical Sciences, Chalmers University of Technology, Gothenburg, Sweden
| |
Collapse
|
14
|
Schnell HM, Jochem M, Micoogullari Y, Riggs CL, Ivanov P, Welsch H, Ravindran R, Anderson P, Robinson LC, Tatchell K, Hanna J. Reg1 and Snf1 regulate stress-induced relocalization of protein phosphatase-1 to cytoplasmic granules. FEBS J 2021; 288:4833-4848. [PMID: 33682330 DOI: 10.1111/febs.15802] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 02/22/2021] [Accepted: 03/03/2021] [Indexed: 11/26/2022]
Abstract
The compartmentalization of cellular function is achieved largely through the existence of membrane-bound organelles. However, recent work suggests a novel mechanism of compartmentalization mediated by membraneless structures that have liquid droplet-like properties and arise through phase separation. Cytoplasmic stress granules (SGs) are the best characterized and are induced by various stressors including arsenite, heat shock, and glucose deprivation. Current models suggest that SGs play an important role in protein homeostasis by mediating reversible translation attenuation. Protein phosphatase-1 (PP1) is a central cellular regulator responsible for most serine/threonine dephosphorylation. Here, we show that upon arsenite stress, PP1's catalytic subunit Glc7 relocalizes to punctate cytoplasmic granules. This altered localization requires PP1's recently described maturation pathway mediated by the multifunctional ATPase Cdc48 and PP1's regulatory subunit Ypi1. Glc7 relocalization is mediated by its regulatory subunit Reg1 and its target Snf1, the AMP-dependent protein kinase. Surprisingly, Glc7 granules are highly specific to arsenite and appear distinct from canonical SGs. Arsenite induces potent translational inhibition, and translational recovery is strongly dependent on Glc7, but independent of Glc7's well-established role in regulating eIF2α. These results suggest a novel form of stress-induced cytoplasmic granule and a new mode of translational control by Glc7.
Collapse
Affiliation(s)
- Helena Maria Schnell
- Department of Pathology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| | - Marco Jochem
- Department of Pathology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| | - Yagmur Micoogullari
- Department of Pathology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| | - Claire Louise Riggs
- Department of Rheumatology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| | - Pavel Ivanov
- Department of Rheumatology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| | - Hendrik Welsch
- Department of Pathology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| | - Rini Ravindran
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Paul Anderson
- Department of Rheumatology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| | - Lucy Christina Robinson
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - Kelly Tatchell
- Department of Biochemistry and Molecular Biology, Louisiana State University Health Sciences Center, Shreveport, LA, USA
| | - John Hanna
- Department of Pathology, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA
| |
Collapse
|
15
|
The regulation of Saccharomyces cerevisiae Snf1 protein kinase on glucose utilization is in a glucose-dependent manner. Curr Genet 2021; 67:245-248. [PMID: 33385241 DOI: 10.1007/s00294-020-01137-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 11/19/2020] [Accepted: 11/21/2020] [Indexed: 01/13/2023]
Abstract
Protein phosphorylation catalyzed by protein kinases is the major regulatory mechanism that controls many cellular processes. The regulatory mechanism of one protein kinase in different signals is distinguished, probably inducing multiple phenotypes. The Saccharomyces cerevisiae Snf1 protein kinase, a member of the AMP‑activated protein kinase family, plays important roles in the response to nutrition and environmental stresses. Glucose is an important nutrient for life activities of cells, but glucose repression and osmotic pressure could be produced at certain concentrations. To deeply understand the role of Snf1 in the regulation of nutrient metabolism and stress response of S. cerevisiae cells, the role and the regulatory mechanism of Snf1 in glucose metabolism are discussed in different level of glucose: below 1% (glucose derepression status), in 2% (glucose repression status), and in 30% glucose (1.66 M, an osmotic equivalent to 0.83 M NaCl). In summary, Snf1 regulates glucose metabolism in a glucose-dependent manner, which is associated with the different regulation on activation, localization, and signal pathways of Snf1 by varied glucose. Exploring the regulatory mechanism of Snf1 in glucose metabolism in different concentrations of glucose can provide insights into the study of the global regulatory mechanism of Snf1 in yeast and can help to better understand the complexity of physiological response of cells to stresses.
Collapse
|
16
|
Schmidt GW, Welkenhuysen N, Ye T, Cvijovic M, Hohmann S. Mig1 localization exhibits biphasic behavior which is controlled by both metabolic and regulatory roles of the sugar kinases. Mol Genet Genomics 2020; 295:1489-1500. [PMID: 32948893 PMCID: PMC7524853 DOI: 10.1007/s00438-020-01715-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 07/20/2020] [Indexed: 12/01/2022]
Abstract
Glucose, fructose and mannose are the preferred carbon/energy sources for the yeast Saccharomyces cerevisiae. Absence of preferred energy sources activates glucose derepression, which is regulated by the kinase Snf1. Snf1 phosphorylates the transcriptional repressor Mig1, which results in its exit from the nucleus and subsequent derepression of genes. In contrast, Snf1 is inactive when preferred carbon sources are available, which leads to dephosphorylation of Mig1 and its translocation to the nucleus where Mig1 acts as a transcription repressor. Here we revisit the role of the three hexose kinases, Hxk1, Hxk2 and Glk1, in glucose de/repression. We demonstrate that all three sugar kinases initially affect Mig1 nuclear localization upon addition of glucose, fructose and mannose. This initial import of Mig1 into the nucleus was temporary; for continuous nucleocytoplasmic shuttling of Mig1, Hxk2 is required in the presence of glucose and mannose and in the presence of fructose Hxk2 or Hxk1 is required. Our data suggest that Mig1 import following exposure to preferred energy sources is controlled via two different pathways, where (1) the initial import is regulated by signals derived from metabolism and (2) continuous shuttling is regulated by the Hxk2 and Hxk1 proteins. Mig1 nucleocytoplasmic shuttling appears to be important for the maintenance of the repressed state in which Hxk1/2 seems to play an essential role.
Collapse
Affiliation(s)
- Gregor W Schmidt
- Department of Biosystems Science and Engineering, ETH Zurich, Basel, Switzerland
| | - Niek Welkenhuysen
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden.,Department of Mathematical Sciences, University of Gothenburg and Chalmers University of Technology, Göteborg, Sweden
| | - Tian Ye
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden
| | - Marija Cvijovic
- Department of Mathematical Sciences, University of Gothenburg and Chalmers University of Technology, Göteborg, Sweden
| | - Stefan Hohmann
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden. .,Department of Biology and Biological Engineering, Chalmers University of Technology, Göteborg, Sweden.
| |
Collapse
|
17
|
Spontaneous mutations that confer resistance to 2-deoxyglucose act through Hxk2 and Snf1 pathways to regulate gene expression and HXT endocytosis. PLoS Genet 2020; 16:e1008484. [PMID: 32673313 PMCID: PMC7386655 DOI: 10.1371/journal.pgen.1008484] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Revised: 07/28/2020] [Accepted: 06/01/2020] [Indexed: 12/31/2022] Open
Abstract
Yeast and fast-growing human tumor cells share metabolic similarities in that both cells use fermentation of glucose for energy and both are highly sensitive to the glucose analog 2-deoxyglucose. Spontaneous mutations in S. cerevisiae that conferred resistance to 2-deoxyglucose were identified by whole genome sequencing. Missense alleles of the HXK2, REG1, GLC7 and SNF1 genes were shown to confer significant resistance to 2-deoxyglucose and all had the potential to alter the activity and or target selection of the Snf1 kinase signaling pathway. All three missense alleles in HXK2 resulted in significantly reduced catalytic activity. Addition of 2DG promotes endocytosis of the glucose transporter Hxt3. All but one of the 2DG-resistant strains reduced the 2DG-mediated hexose transporter endocytosis by increasing plasma membrane occupancy of the Hxt3 protein. Increased expression of the DOG (deoxyglucose) phosphatases has been associated with resistance to 2-deoxyglucose. Expression of both the DOG1 and DOG2 mRNA was elevated after treatment with 2-deoxyglucose but induction of these genes is not associated with 2DG-resistance. RNAseq analysis of the transcriptional response to 2DG showed large scale, genome-wide changes in mRNA abundance that were greatly reduced in the 2DG resistant strains. These findings suggest the common adaptive response to 2DG is to limit the magnitude of the response. Genetic studies of 2DG resistance using the dominant SNF1-G53R allele in cells that are genetically compromised in both the endocytosis and DOG pathways suggest that at least one more mechanism for conferring resistance to this glucose analog remains to be discovered. Yeast and fast-growing human tumor cells share metabolic similarities in that both cells use fermentation of glucose for energy and both are highly sensitive to the glucose analog 2-deoxyglucose. Another similarity between yeast cells and human tumor cells is that both cells can acquire resistance to 2-deoxyglucose, an outcome that can limit the usefulness of some cancer therapeutics. In this study, we used bakers’ yeast as a model organism to better understand the mechanism of toxicity and acquisition of resistance to 2-deoxyglucose. Spontaneous mutations in S. cerevisiae that conferred resistance to 2-deoxyglucose were isolated and identified by whole genome sequencing, a technology that was not available until recently. Our studies indicate that 2-deoxyglucose becomes toxic after it is phosphorylated by an enzyme called hexokinase. One important route to resistance is to reduce hexokinase activity. Other parallel pathways to resistance include increased expression of a hydrolase that degrades the toxic metabolite, altered localization of glucose transporters and altered glucose signal transduction pathways.
Collapse
|
18
|
Abstract
Many sensory and chemical signal inputs are transmitted by intracellular GTP-binding (G) proteins. G proteins make up two major subfamilies: "large" G proteins comprising three subunits and "small" G proteins, such as the proto-oncogene product RAS, which contains a single subunit. Members of both subfamilies are regulated by post-translational modifications, including lipidation, proteolysis, and carboxyl methylation. Emerging studies have shown that these proteins are also modified by ubiquitination. Much of our current understanding of this post-translational modification comes from investigations of the large G-protein α subunit from yeast (Gpa1) and the three RAS isotypes in humans, NRAS, KRAS, and HRAS. Gα undergoes both mono- and polyubiquitination, and these modifications have distinct consequences for determining the sites and mechanisms of its degradation. Genetic and biochemical reconstitution studies have revealed the enzymes and binding partners required for addition and removal of ubiquitin, as well as the delivery and destruction of both the mono- and polyubiquitinated forms of the G protein. Complementary studies of RAS have identified multiple ubiquitination sites, each having distinct consequences for binding to regulatory proteins, shuttling to and from the plasma membrane, and degradation. Here, we review what is currently known about these two well-studied examples, Gpa1 and the human RAS proteins, that have revealed additional mechanisms of signal regulation and dysregulation relevant to human physiology. We also compare and contrast the effects of G-protein ubiquitination with other post-translational modifications of these proteins.
Collapse
Affiliation(s)
- Henrik G Dohlman
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599.
| | - Sharon L Campbell
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599.
| |
Collapse
|
19
|
Myers KS, Riley NM, MacGilvray ME, Sato TK, McGee M, Heilberger J, Coon JJ, Gasch AP. Rewired cellular signaling coordinates sugar and hypoxic responses for anaerobic xylose fermentation in yeast. PLoS Genet 2019; 15:e1008037. [PMID: 30856163 PMCID: PMC6428351 DOI: 10.1371/journal.pgen.1008037] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Revised: 03/21/2019] [Accepted: 02/20/2019] [Indexed: 01/08/2023] Open
Abstract
Microbes can be metabolically engineered to produce biofuels and biochemicals, but rerouting metabolic flux toward products is a major hurdle without a systems-level understanding of how cellular flux is controlled. To understand flux rerouting, we investigated a panel of Saccharomyces cerevisiae strains with progressive improvements in anaerobic fermentation of xylose, a sugar abundant in sustainable plant biomass used for biofuel production. We combined comparative transcriptomics, proteomics, and phosphoproteomics with network analysis to understand the physiology of improved anaerobic xylose fermentation. Our results show that upstream regulatory changes produce a suite of physiological effects that collectively impact the phenotype. Evolved strains show an unusual co-activation of Protein Kinase A (PKA) and Snf1, thus combining responses seen during feast on glucose and famine on non-preferred sugars. Surprisingly, these regulatory changes were required to mount the hypoxic response when cells were grown on xylose, revealing a previously unknown connection between sugar source and anaerobic response. Network analysis identified several downstream transcription factors that play a significant, but on their own minor, role in anaerobic xylose fermentation, consistent with the combinatorial effects of small-impact changes. We also discovered that different routes of PKA activation produce distinct phenotypes: deletion of the RAS/PKA inhibitor IRA2 promotes xylose growth and metabolism, whereas deletion of PKA inhibitor BCY1 decouples growth from metabolism to enable robust fermentation without division. Comparing phosphoproteomic changes across ira2Δ and bcy1Δ strains implicated regulatory changes linked to xylose-dependent growth versus metabolism. Together, our results present a picture of the metabolic logic behind anaerobic xylose flux and suggest that widespread cellular remodeling, rather than individual metabolic changes, is an important goal for metabolic engineering.
Collapse
Affiliation(s)
- Kevin S. Myers
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, United States of America
| | - Nicholas M. Riley
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, United States of America
| | - Matthew E. MacGilvray
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, United States of America
| | - Trey K. Sato
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, United States of America
| | - Mick McGee
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, United States of America
| | - Justin Heilberger
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, United States of America
| | - Joshua J. Coon
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, United States of America
- Genome Center of Wisconsin, University of Wisconsin-Madison, Madison, WI, United States of America
- Department of Biomolecular Chemistry, University of Wisconsin-Madison, Madison, WI, United States of America
- Morgridge Institute for Research, Madison, WI, United States of America
| | - Audrey P. Gasch
- Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, United States of America
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI, United States of America
- Genome Center of Wisconsin, University of Wisconsin-Madison, Madison, WI, United States of America
| |
Collapse
|
20
|
Van Ende M, Wijnants S, Van Dijck P. Sugar Sensing and Signaling in Candida albicans and Candida glabrata. Front Microbiol 2019; 10:99. [PMID: 30761119 PMCID: PMC6363656 DOI: 10.3389/fmicb.2019.00099] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/16/2019] [Indexed: 12/30/2022] Open
Abstract
Candida species, such as Candida albicans and Candida glabrata, cause infections at different host sites because they adapt their metabolism depending on the available nutrients. They are able to proliferate under both nutrient-rich and nutrient-poor conditions. This adaptation is what makes these fungi successful pathogens. For both species, sugars are very important nutrients and as the sugar level differs depending on the host niche, different sugar sensing systems must be present. Saccharomyces cerevisiae has been used as a model for the identification of these sugar sensing systems. One of the main carbon sources for yeast is glucose, for which three different pathways have been described. First, two transporter-like proteins, ScSnf3 and ScRgt2, sense glucose levels resulting in the induction of different hexose transporter genes. This situation is comparable in C. albicans and C. glabrata, where sensing of glucose by CaHgt4 and CgSnf3, respectively, also results in hexose transporter gene induction. The second glucose sensing mechanism in S. cerevisiae is via the G-protein coupled receptor ScGpr1, which causes the activation of the cAMP/PKA pathway, resulting in rapid adaptation to the presence of glucose. The main components of this glucose sensing system are also conserved in C. albicans and C. glabrata. However, it seems that the ligand(s) for CaGpr1 are not sugars but lactate and methionine. In C. glabrata, this pathway has not yet been investigated. Finally, the glucose repression pathway ensures repression of respiration and repression of the use of alternative carbon sources. This pathway is not well characterized in Candida species. It is important to note that, apart from glucose, other sugars and sugar-analogs, such as N-acetylglucosamine in the case of C. albicans, are also important carbon sources. In these fungal pathogens, sensing sugars is important for a number of virulence attributes, including adhesion, oxidative stress resistance, biofilm formation, morphogenesis, invasion, and antifungal drug tolerance. In this review, the sugar sensing and signaling mechanisms in these Candida species are compared to S. cerevisiae.
Collapse
Affiliation(s)
- Mieke Van Ende
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| | - Stefanie Wijnants
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| | - Patrick Van Dijck
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, Department of Biology, KU Leuven, Leuven, Belgium
- VIB-KU Leuven Center for Microbiology, Leuven, Belgium
| |
Collapse
|
21
|
Coccetti P, Nicastro R, Tripodi F. Conventional and emerging roles of the energy sensor Snf1/AMPK in Saccharomyces cerevisiae. MICROBIAL CELL 2018; 5:482-494. [PMID: 30483520 PMCID: PMC6244292 DOI: 10.15698/mic2018.11.655] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
All proliferating cells need to match metabolism, growth and cell cycle progression with nutrient availability to guarantee cell viability in spite of a changing environment. In yeast, a signaling pathway centered on the effector kinase Snf1 is required to adapt to nutrient limitation and to utilize alternative carbon sources, such as sucrose and ethanol. Snf1 shares evolutionary conserved functions with the AMP-activated Kinase (AMPK) in higher eukaryotes which, activated by energy depletion, stimulates catabolic processes and, at the same time, inhibits anabolism. Although the yeast Snf1 is best known for its role in responding to a number of stress factors, in addition to glucose limitation, new unconventional roles of Snf1 have recently emerged, even in glucose repressing and unstressed conditions. Here, we review and integrate available data on conventional and non-conventional functions of Snf1 to better understand the complexity of cellular physiology which controls energy homeostasis.
Collapse
Affiliation(s)
- Paola Coccetti
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy.,SYSBIO, Centre of Systems Biology, Milan, Italy
| | - Raffaele Nicastro
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy.,Present address: Department of Biology, University of Fribourg, Fribourg, Switzerland
| | - Farida Tripodi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy.,SYSBIO, Centre of Systems Biology, Milan, Italy
| |
Collapse
|
22
|
Garcia-Gimeno MA, Rodilla-Ramirez PN, Viana R, Salas-Puig X, Brewer MK, Gentry MS, Sanz P. A novel EPM2A mutation yields a slow progression form of Lafora disease. Epilepsy Res 2018; 145:169-177. [PMID: 30041081 DOI: 10.1016/j.eplepsyres.2018.07.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/11/2018] [Accepted: 07/13/2018] [Indexed: 12/19/2022]
Abstract
Lafora disease (LD, OMIM 254780) is a rare disorder characterized by epilepsy and neurodegeneration leading patients to a vegetative state and death, usually within the first decade from the onset of the first symptoms. In the vast majority of cases LD is related to mutations in either the EPM2A gene (encoding the glucan phosphatase laforin) or the EPM2B gene (encoding the E3-ubiquitin ligase malin). In this work, we characterize the mutations present in the EPM2A gene in a patient displaying a slow progression form of the disease. The patient is compound heterozygous with Y112X and N163D mutations in the corresponding alleles. In primary fibroblasts obtained from the patient, we analyzed the expression of the mutated alleles by quantitative real time PCR and found slightly lower levels of expression of the EPM2A gene respect to control cells. However, by Western blotting we were unable to detect endogenous levels of the protein in crude extracts from patient fibroblasts. The Y112X mutation would render a truncated protein lacking the phosphatase domain and likely degraded. Since minute amounts of laforin-N163D might still play a role in cell physiology, we analyzed the biochemical characteristics of the N163D mutation. We found that recombinant laforin N163D protein was as stable as wild type and exhibited near wild type phosphatase activity towards biologically relevant substrates. On the contrary, it showed a severe impairment in the interaction profile with previously identified laforin binding partners. These results lead us to conclude that the slow progression of the disease present in this patient could be either due to the specific biochemical properties of laforin N163D or to the presence of alternative genetic modifying factors separate from pathogenicity.
Collapse
Affiliation(s)
| | | | - Rosa Viana
- IBV-CSIC. Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Xavier Salas-Puig
- Epilepsy Unit, Neurology Dept., Hospital Vall Hebron, Barcelona, Spain
| | - M Kathryn Brewer
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, USA
| | - Matthew S Gentry
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, USA; Lafora Epilepsy Cure Initiative, USA
| | - Pascual Sanz
- IBV-CSIC. Instituto de Biomedicina de Valencia, Consejo Superior de Investigaciones Científicas, Valencia, Spain; CIBERER. Centro de Investigación Biomédica en Red de Enfermedades Raras, Valencia, Spain; Lafora Epilepsy Cure Initiative, USA.
| |
Collapse
|
23
|
Shashkova S, Wollman AJM, Leake MC, Hohmann S. The yeast Mig1 transcriptional repressor is dephosphorylated by glucose-dependent and -independent mechanisms. FEMS Microbiol Lett 2018; 364:3884263. [PMID: 28854669 DOI: 10.1093/femsle/fnx133] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2016] [Accepted: 06/21/2017] [Indexed: 12/28/2022] Open
Abstract
A yeast Saccharomyces cerevisiae Snf1 kinase, an analog of mammalian AMPK, regulates glucose derepression of genes required for utilization of alternative carbon sources through the transcriptional repressor Mig1. It has been suggested that the Glc7-Reg1 phosphatase dephosphorylates Mig1. Here we report that Mig1 is dephosphorylated by Glc7-Reg1 in an apparently glucose-dependent mechanism but also by a mechanism independent of glucose and Glc7-Reg1. In addition to serine/threonine phosphatases another process including tyrosine phosphorylation seems crucial for Mig1 regulation. Taken together, Mig1 dephosphorylation appears to be controlled in a complex manner, in line with the importance for rapid and sensitive regulation upon altered glucose concentrations in the growth medium.
Collapse
Affiliation(s)
- Sviatlana Shashkova
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Göteborg, Sweden.,Biological Physical Sciences Institute, University of York, York YO10 5DD, UK
| | - Adam J M Wollman
- Biological Physical Sciences Institute, University of York, York YO10 5DD, UK
| | - Mark C Leake
- Biological Physical Sciences Institute, University of York, York YO10 5DD, UK
| | - Stefan Hohmann
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Göteborg, Sweden.,Department of Biology and Biological Engineering, Chalmers University of Technology, 41296 Göteborg, Sweden
| |
Collapse
|
24
|
Abstract
Mammalian AMP-activated protein kinase (AMPK) is a Ser/Thr protein kinase that acts as a crucial energy sensor in the cell. Since AMPK plays a key role in a multitude of different pathways in the cell, major efforts have been concentrated to elucidate its signaling network, mainly by the identification of AMPK downstream targets. In this chapter we describe a yeast two-hybrid method for the direct evaluation of the interaction between an AMPK subunit and putative substrates.
Collapse
Affiliation(s)
- Pascual Sanz
- Instituto de Biomedicina de Valencia, CSIC and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain.
| | - Rosa Viana
- Instituto de Biomedicina de Valencia, CSIC and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Valencia, Spain
| | - Maria Adelaida Garcia-Gimeno
- Department of Biotecnología, Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural (ETSIAMN), University of Politécnica de Valencia, Valencia, Spain
| |
Collapse
|
25
|
Broeckx T, Hulsmans S, Rolland F. The plant energy sensor: evolutionary conservation and divergence of SnRK1 structure, regulation, and function. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:6215-6252. [PMID: 27856705 DOI: 10.1093/jxb/erw416] [Citation(s) in RCA: 151] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The SnRK1 (SNF1-related kinase 1) kinases are the plant cellular fuel gauges, activated in response to energy-depleting stress conditions to maintain energy homeostasis while also gatekeeping important developmental transitions for optimal growth and survival. Similar to their opisthokont counterparts (animal AMP-activated kinase, AMPK, and yeast Sucrose Non-Fermenting 1, SNF), they function as heterotrimeric complexes with a catalytic (kinase) α subunit and regulatory β and γ subunits. Although the overall configuration of the kinase complexes is well conserved, plant-specific structural modifications (including a unique hybrid βγ subunit) and associated differences in regulation reflect evolutionary divergence in response to fundamentally different lifestyles. While AMP is the key metabolic signal activating AMPK in animals, the plant kinases appear to be allosterically inhibited by sugar-phosphates. Their function is further fine-tuned by differential subunit expression, localization, and diverse post-translational modifications. The SnRK1 kinases act by direct phosphorylation of key metabolic enzymes and regulatory proteins, extensive transcriptional regulation (e.g. through bZIP transcription factors), and down-regulation of TOR (target of rapamycin) kinase signaling. Significant progress has been made in recent years. New tools and more directed approaches will help answer important fundamental questions regarding their structure, regulation, and function, as well as explore their potential as targets for selection and modification for improved plant performance in a changing environment.
Collapse
Affiliation(s)
- Tom Broeckx
- Laboratory for Molecular Plant Biology, Biology Department, University of Leuven-KU Leuven, Kasteelpark Arenberg 31, 3001 Heverlee-Leuven, Belgium
| | - Sander Hulsmans
- Laboratory for Molecular Plant Biology, Biology Department, University of Leuven-KU Leuven, Kasteelpark Arenberg 31, 3001 Heverlee-Leuven, Belgium
| | - Filip Rolland
- Laboratory for Molecular Plant Biology, Biology Department, University of Leuven-KU Leuven, Kasteelpark Arenberg 31, 3001 Heverlee-Leuven, Belgium
| |
Collapse
|
26
|
Springing into Action: Reg2 Negatively Regulates Snf1 Protein Kinase and Facilitates Recovery from Prolonged Glucose Starvation in Saccharomyces cerevisiae. Appl Environ Microbiol 2016; 82:3875-3885. [PMID: 27107116 DOI: 10.1128/aem.00154-16] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 04/14/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Glucose is the preferred carbon source for the yeast Saccharomyces cerevisiae Glucose limitation activates Snf1 protein kinase, a key regulator of energy homeostasis that promotes utilization of alternative carbon sources and enforces energy conservation. Snf1 activation requires phosphorylation of its T-loop threonine (Thr210) by upstream kinases. When glucose is abundant, Snf1 is inhibited by Thr210 dephosphorylation. This involves the function of the type 1 protein phosphatase Glc7, which is targeted to Snf1 by a regulatory subunit, Reg1. The reg1 mutation causes increased Snf1 activity and mimics various aspects of glucose limitation, including slower growth. Reg2 is another Glc7 regulatory subunit encoded by a paralogous gene, REG2 Previous evidence indicated that the reg2 mutation exacerbates the Snf1-dependent slow-growth phenotype caused by reg1, suggesting a link between Reg2 and Snf1. Here, we explore this link in more detail and present evidence that Reg2 contributes to Snf1 Thr210 dephosphorylation. Consistent with this role, Reg2 interacts with wild-type Snf1 but not with nonphosphorylatable Snf1-T210A. Reg2 accumulation increases in a Snf1-dependent manner during prolonged glucose deprivation, and glucose-starved cells lacking Reg2 exhibit delayed Snf1 Thr210 dephosphorylation and slower growth recovery upon glucose replenishment. Accordingly, cells lacking Reg2 are outcompeted by wild-type cells in the course of several glucose starvation/replenishment cycles. Collectively, our results support a model in which Reg2-Glc7 contributes to the negative control of Snf1 in response to glucose refeeding after prolonged starvation. The competitive growth advantage provided by Reg2 underscores the evolutionary significance of this paralog for S. cerevisiae IMPORTANCE The ability of microorganisms to respond to stress is essential for their survival. However, rapid recovery from stress could be equally crucial in competitive environments. Therefore, a wise stress response program should prepare cells for quick recovery upon reexposure to favorable conditions. Glucose is the preferred carbon source for the yeast S. cerevisiae Glucose depletion activates the stress response protein kinase Snf1, which functions to limit energy-consuming processes, such as growth. We show that prolonged glucose deprivation also leads to Snf1-dependent accumulation of Reg2 and that this protein helps to inhibit Snf1 and to accelerate growth recovery upon glucose replenishment. Cells lacking Reg2 are readily outcompeted by wild-type cells during glucose depletion/replenishment cycles. Thus, while prolonged glucose deprivation might seem to put yeast cells "on their knees," concomitant accumulation of Reg2 helps configure the cells into a "sprinter's crouch start position" to spring into action once glucose becomes available.
Collapse
|
27
|
Hübscher V, Mudholkar K, Chiabudini M, Fitzke E, Wölfle T, Pfeifer D, Drepper F, Warscheid B, Rospert S. The Hsp70 homolog Ssb and the 14-3-3 protein Bmh1 jointly regulate transcription of glucose repressed genes in Saccharomyces cerevisiae. Nucleic Acids Res 2016; 44:5629-45. [PMID: 27001512 PMCID: PMC4937304 DOI: 10.1093/nar/gkw168] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 03/03/2016] [Indexed: 11/26/2022] Open
Abstract
Chaperones of the Hsp70 family interact with a multitude of newly synthesized polypeptides and prevent their aggregation. Saccharomyces cerevisiae cells lacking the Hsp70 homolog Ssb suffer from pleiotropic defects, among others a defect in glucose-repression. The highly conserved heterotrimeric kinase SNF1/AMPK (AMP-activated protein kinase) is required for the release from glucose-repression in yeast and is a key regulator of energy balance also in mammalian cells. When glucose is available the phosphatase Glc7 keeps SNF1 in its inactive, dephosphorylated state. Dephosphorylation depends on Reg1, which mediates targeting of Glc7 to its substrate SNF1. Here we show that the defect in glucose-repression in the absence of Ssb is due to the ability of the chaperone to bridge between the SNF1 and Glc7 complexes. Ssb performs this post-translational function in concert with the 14-3-3 protein Bmh, to which Ssb binds via its very C-terminus. Raising the intracellular concentration of Ssb or Bmh enabled Glc7 to dephosphorylate SNF1 even in the absence of Reg1. By that Ssb and Bmh efficiently suppressed transcriptional deregulation of Δreg1 cells. The findings reveal that Ssb and Bmh comprise a new chaperone module, which is involved in the fine tuning of a phosphorylation-dependent switch between respiration and fermentation.
Collapse
Affiliation(s)
- Volker Hübscher
- Institute of Biochemistry and Molecular Biology, ZBMZ, University of Freiburg, D-79104 Freiburg, Germany
| | - Kaivalya Mudholkar
- Institute of Biochemistry and Molecular Biology, ZBMZ, University of Freiburg, D-79104 Freiburg, Germany
| | - Marco Chiabudini
- Institute of Biochemistry and Molecular Biology, ZBMZ, University of Freiburg, D-79104 Freiburg, Germany BIOSS Centre for Biological Signaling Studies, University of Freiburg, D-79104 Freiburg, Germany
| | - Edith Fitzke
- Institute of Biochemistry and Molecular Biology, ZBMZ, University of Freiburg, D-79104 Freiburg, Germany
| | - Tina Wölfle
- Institute of Biochemistry and Molecular Biology, ZBMZ, University of Freiburg, D-79104 Freiburg, Germany
| | - Dietmar Pfeifer
- Genomics Lab, Department of Hematology, Oncology and Stem Cell Transplantation, University Medical Center, University of Freiburg, D-79106 Freiburg, Germany
| | - Friedel Drepper
- BIOSS Centre for Biological Signaling Studies, University of Freiburg, D-79104 Freiburg, Germany Department of Biochemistry and Functional Proteomics, Faculty of Biology, University of Freiburg, D-79104 Freiburg, Germany
| | - Bettina Warscheid
- BIOSS Centre for Biological Signaling Studies, University of Freiburg, D-79104 Freiburg, Germany Department of Biochemistry and Functional Proteomics, Faculty of Biology, University of Freiburg, D-79104 Freiburg, Germany
| | - Sabine Rospert
- Institute of Biochemistry and Molecular Biology, ZBMZ, University of Freiburg, D-79104 Freiburg, Germany BIOSS Centre for Biological Signaling Studies, University of Freiburg, D-79104 Freiburg, Germany
| |
Collapse
|
28
|
Roque E, Fares MA, Yenush L, Rochina MC, Wen J, Mysore KS, Gómez-Mena C, Beltrán JP, Cañas LA. Evolution by gene duplication of Medicago truncatula PISTILLATA-like transcription factors. JOURNAL OF EXPERIMENTAL BOTANY 2016; 67:1805-1817. [PMID: 26773809 PMCID: PMC4783364 DOI: 10.1093/jxb/erv571] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
PISTILLATA (PI) is a member of the B-function MADS-box gene family, which controls the identity of both petals and stamens in Arabidopsis thaliana. In Medicago truncatula (Mt), there are two PI-like paralogs, known as MtPI and MtNGL9. These genes differ in their expression patterns, but it is not known whether their functions have also diverged. Describing the evolution of certain duplicated genes, such as transcription factors, remains a challenge owing to the complex expression patterns and functional divergence between the gene copies. Here, we report a number of functional studies, including analyses of gene expression, protein-protein interactions, and reverse genetic approaches designed to demonstrate the respective contributions of each M. truncatula PI-like paralog to the B-function in this species. Also, we have integrated molecular evolution approaches to determine the mode of evolution of Mt PI-like genes after duplication. Our results demonstrate that MtPI functions as a master regulator of B-function in M. truncatula, maintaining the overall ancestral function, while MtNGL9 does not seem to have a role in this regard, suggesting that the pseudogenization could be the functional evolutionary fate for this gene. However, we provide evidence that purifying selection is the primary evolutionary force acting on this paralog, pinpointing the conservation of its biochemical function and, alternatively, the acquisition of a new role for this gene.
Collapse
Affiliation(s)
- Edelín Roque
- Instituto de Biología Molecular y Celular de Plantas Consejo Superior de Investigaciones Científicas & Universidad Politécnica de Valencia (CSIC-UPV), Ciudad Politécnica de la Innovación, Edf. 8E, C/ Ingeniero Fausto Elio s/n, E-46011 Valencia, Spain
| | - Mario A Fares
- Instituto de Biología Molecular y Celular de Plantas Consejo Superior de Investigaciones Científicas & Universidad Politécnica de Valencia (CSIC-UPV), Ciudad Politécnica de la Innovación, Edf. 8E, C/ Ingeniero Fausto Elio s/n, E-46011 Valencia, Spain
| | - Lynne Yenush
- Instituto de Biología Molecular y Celular de Plantas Consejo Superior de Investigaciones Científicas & Universidad Politécnica de Valencia (CSIC-UPV), Ciudad Politécnica de la Innovación, Edf. 8E, C/ Ingeniero Fausto Elio s/n, E-46011 Valencia, Spain
| | - Mari Cruz Rochina
- Instituto de Biología Molecular y Celular de Plantas Consejo Superior de Investigaciones Científicas & Universidad Politécnica de Valencia (CSIC-UPV), Ciudad Politécnica de la Innovación, Edf. 8E, C/ Ingeniero Fausto Elio s/n, E-46011 Valencia, Spain
| | - Jiangqi Wen
- Plant Biology Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK 73401, USA
| | - Kirankumar S Mysore
- Plant Biology Division, The Samuel Roberts Noble Foundation, 2510 Sam Noble Parkway, Ardmore, OK 73401, USA
| | - Concepción Gómez-Mena
- Instituto de Biología Molecular y Celular de Plantas Consejo Superior de Investigaciones Científicas & Universidad Politécnica de Valencia (CSIC-UPV), Ciudad Politécnica de la Innovación, Edf. 8E, C/ Ingeniero Fausto Elio s/n, E-46011 Valencia, Spain
| | - José Pío Beltrán
- Instituto de Biología Molecular y Celular de Plantas Consejo Superior de Investigaciones Científicas & Universidad Politécnica de Valencia (CSIC-UPV), Ciudad Politécnica de la Innovación, Edf. 8E, C/ Ingeniero Fausto Elio s/n, E-46011 Valencia, Spain
| | - Luis A Cañas
- Instituto de Biología Molecular y Celular de Plantas Consejo Superior de Investigaciones Científicas & Universidad Politécnica de Valencia (CSIC-UPV), Ciudad Politécnica de la Innovación, Edf. 8E, C/ Ingeniero Fausto Elio s/n, E-46011 Valencia, Spain
| |
Collapse
|
29
|
Sanz P, Viana R, Garcia-Gimeno MA. AMPK in Yeast: The SNF1 (Sucrose Non-fermenting 1) Protein Kinase Complex. EXPERIENTIA SUPPLEMENTUM (2012) 2016; 107:353-374. [PMID: 27812987 DOI: 10.1007/978-3-319-43589-3_14] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
In yeast, SNF1 protein kinase is the orthologue of mammalian AMPK complex. It is a trimeric complex composed of Snf1 protein kinase (orthologue of AMPKα catalytic subunit), Snf4 (orthologue of AMPKγ regulatory subunit), and a member of the Gal83/Sip1/Sip2 family of proteins (orthologues of AMPKβ subunit) that act as scaffolds and also regulate the subcellular localization of the complex. In this chapter, we review the recent literature on the characteristics of SNF1 complex subunits, the structure and regulation of the activity of the SNF1 complex, its role at the level of transcriptional regulation of relevant target genes and also at the level of posttranslational modification of targeted substrates. We also review the crosstalk of SNF1 complex activity with other key protein kinase pathways such as cAMP-PKA, TORC1, and PAS kinase.
Collapse
Affiliation(s)
- Pascual Sanz
- Instituto de Biomedicina de Valencia, CSIC and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCiii), Jaime Roig 11, 46010, Valencia, Spain.
| | - Rosa Viana
- Instituto de Biomedicina de Valencia, CSIC and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER-ISCiii), Jaime Roig 11, 46010, Valencia, Spain
| | - Maria Adelaida Garcia-Gimeno
- Department of Biotecnología, Escuela Técnica Superior de Ingeniería Agronómica y del Medio Natural (ETSIAMN), Universitat Politécnica de Valencia, Valencia, Spain
| |
Collapse
|
30
|
Kingsbury JM, Sen ND, Cardenas ME. Branched-Chain Aminotransferases Control TORC1 Signaling in Saccharomyces cerevisiae. PLoS Genet 2015; 11:e1005714. [PMID: 26659116 PMCID: PMC4684349 DOI: 10.1371/journal.pgen.1005714] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 11/09/2015] [Indexed: 11/18/2022] Open
Abstract
The conserved target of rapamycin complex 1 (TORC1) integrates nutrient signals to orchestrate cell growth and proliferation. Leucine availability is conveyed to control TORC1 activity via the leu-tRNA synthetase/EGOC-GTPase module in yeast and mammals, but the mechanisms sensing leucine remain only partially understood. We show here that both leucine and its α-ketoacid metabolite, α-ketoisocaproate, effectively activate the yeast TORC1 kinase via both EGOC GTPase-dependent and -independent mechanisms. Leucine and α-ketoisocaproate are interconverted by ubiquitous branched-chain aminotransferases (BCAT), which in yeast are represented by the mitochondrial and cytosolic enzymes Bat1 and Bat2, respectively. BCAT yeast mutants exhibit severely compromised TORC1 activity, which is partially restored by expression of Bat1 active site mutants, implicating both catalytic and structural roles of BCATs in TORC1 control. We find that Bat1 interacts with branched-chain amino acid metabolic enzymes and, in a leucine-dependent fashion, with the tricarboxylic acid (TCA)-cycle enzyme aconitase. BCAT mutation perturbed TCA-cycle intermediate levels, consistent with a TCA-cycle block, and resulted in low ATP levels, activation of AMPK, and TORC1 inhibition. We propose the biosynthetic capacity of BCAT and its role in forming multicomplex metabolons connecting branched-chain amino acids and TCA-cycle metabolism governs TCA-cycle flux to activate TORC1 signaling. Because mammalian mitochondrial BCAT is known to form a supramolecular branched-chain α-keto acid dehydrogenase enzyme complex that links leucine metabolism to the TCA-cycle, these findings establish a precedent for understanding TORC1 signaling in mammals. In all organisms from yeasts to mammals the target of rapamycin TORC1 pathway controls growth in response to nutrients such as leucine, but the leucine sensing mechanisms are only partially characterized. We show that both leucine and its α-ketoacid metabolite, α-ketoisocaproate, are similarly capable of activating TORC1 kinase via EGOC GTPase-dependent and -independent mechanisms. Activation of TORC1 by leucine or α-ketoisocaproate is only partially mediated via EGOC-GTPase. Leucine and α-ketoisocaproate are interconverted by ubiquitous branched-chain aminotransferases (BCAT). Disruption of BCAT caused reduced TORC1 activity, which was partially restored by expression of BCAT active site mutants, arguing for both structural and catalytic roles of BCAT in TORC1 control. We find BCAT interacts with several branched-chain amino acid metabolic enzymes, and in a leucine-dependent fashion with the tricarboxylic acid (TCA)-cycle enzyme aconitase. Both aconitase mutation or TCA-cycle inhibition impaired TORC1 activity. Mutation of BCAT resulted in a TCA-cycle intermediate profile consistent with a TCA-cycle block, low ATP levels, activation of AMPK, and TORC1 inhibition. Our results suggest a model whereby BCAT coordinates leucine and TCA cycle metabolism to control TORC1 signaling. Taken together, our findings forge key insights into how the TORC1 signaling cascade senses nutrients to control cell growth.
Collapse
Affiliation(s)
- Joanne M Kingsbury
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Neelam D Sen
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Maria E Cardenas
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| |
Collapse
|
31
|
Viana R, Lujan P, Sanz P. The laforin/malin E3-ubiquitin ligase complex ubiquitinates pyruvate kinase M1/M2. BMC BIOCHEMISTRY 2015; 16:24. [PMID: 26493215 PMCID: PMC4619252 DOI: 10.1186/s12858-015-0053-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 10/14/2015] [Indexed: 11/13/2022]
Abstract
BACKGROUND Lafora disease (LD, OMIM 254780) is a fatal neurodegenerative disorder produced mainly by mutations in two genes: EPM2A, encoding the dual specificity phosphatase laforin, and EPM2B, encoding the E3-ubiquitin ligase malin. Although it is known that laforin and malin may form a functional complex, the underlying molecular mechanisms of this pathology are still far from being understood. METHODS In order to gain information about the substrates of the laforin/malin complex, we have carried out a yeast substrate-trapping screening, originally designed to identify substrates of protein tyrosine phosphatases. RESULTS Our results identify the two muscular isoforms of pyruvate kinase (PKM1 and PKM2) as novel interaction partners of laforin. CONCLUSIONS We present evidence indicating that the laforin/malin complex is able to interact with and ubiquitinate both PKM1 and PKM2. This post-translational modification, although it does not affect the catalytic activity of PKM1, it impairs the nuclear localization of PKM2.
Collapse
Affiliation(s)
- Rosa Viana
- Instituto de Biomedicina de Valencia, CSIC, and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Jaime Roig 11, 46010, Valencia, Spain.
| | - Pablo Lujan
- Instituto de Biomedicina de Valencia, CSIC, and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Jaime Roig 11, 46010, Valencia, Spain.
| | - Pascual Sanz
- Instituto de Biomedicina de Valencia, CSIC, and Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Jaime Roig 11, 46010, Valencia, Spain.
| |
Collapse
|
32
|
Lubitz T, Welkenhuysen N, Shashkova S, Bendrioua L, Hohmann S, Klipp E, Krantz M. Network reconstruction and validation of the Snf1/AMPK pathway in baker's yeast based on a comprehensive literature review. NPJ Syst Biol Appl 2015; 1:15007. [PMID: 28725459 PMCID: PMC5516868 DOI: 10.1038/npjsba.2015.7] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Revised: 06/19/2015] [Accepted: 07/14/2015] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND/OBJECTIVES The SNF1/AMPK protein kinase has a central role in energy homeostasis in eukaryotic cells. It is activated by energy depletion and stimulates processes leading to the production of ATP while it downregulates ATP-consuming processes. The yeast SNF1 complex is best known for its role in glucose derepression. METHODS We performed a network reconstruction of the Snf1 pathway based on a comprehensive literature review. The network was formalised in the rxncon language, and we used the rxncon toolbox for model validation and gap filling. RESULTS We present a machine-readable network definition that summarises the mechanistic knowledge of the Snf1 pathway. Furthermore, we used the known input/output relationships in the network to identify and fill gaps in the information transfer through the pathway, to produce a functional network model. Finally, we convert the functional network model into a rule-based model as a proof-of-principle. CONCLUSIONS The workflow presented here enables large scale reconstruction, validation and gap filling of signal transduction networks. It is analogous to but distinct from that established for metabolic networks. We demonstrate the workflow capabilities, and the direct link between the reconstruction and dynamic modelling, with the Snf1 network. This network is a distillation of the knowledge from all previous publications on the Snf1/AMPK pathway. The network is a knowledge resource for modellers and experimentalists alike, and a template for similar efforts in higher eukaryotes. Finally, we envisage the workflow as an instrumental tool for reconstruction of large signalling networks across Eukaryota.
Collapse
Affiliation(s)
- Timo Lubitz
- Theoretical Biophysics, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Niek Welkenhuysen
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden
| | - Sviatlana Shashkova
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden
| | - Loubna Bendrioua
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden
| | - Stefan Hohmann
- Department of Chemistry and Molecular Biology, University of Gothenburg, Göteborg, Sweden
| | - Edda Klipp
- Theoretical Biophysics, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Marcus Krantz
- Theoretical Biophysics, Humboldt-Universität zu Berlin, Berlin, Germany
| |
Collapse
|
33
|
Simpson-Lavy KJ, Bronstein A, Kupiec M, Johnston M. Cross-Talk between Carbon Metabolism and the DNA Damage Response in S. cerevisiae. Cell Rep 2015; 12:1865-75. [PMID: 26344768 DOI: 10.1016/j.celrep.2015.08.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 07/29/2015] [Accepted: 08/07/2015] [Indexed: 12/20/2022] Open
Abstract
Yeast cells with DNA damage avoid respiration, presumably because products of oxidative metabolism can be harmful to DNA. We show that DNA damage inhibits the activity of the Snf1 (AMP-activated) protein kinase (AMPK), which activates expression of genes required for respiration. Glucose and DNA damage upregulate SUMOylation of Snf1, catalyzed by the SUMO E3 ligase Mms21, which inhibits SNF1 activity. The DNA damage checkpoint kinases Mec1/ATR and Tel1/ATM, as well as the nutrient-sensing protein kinase A (PKA), regulate Mms21 activity toward Snf1. Mec1 and Tel1 are required for two SNF1-regulated processes-glucose sensing and ADH2 gene expression-even without exogenous genotoxic stress. Our results imply that inhibition of Snf1 by SUMOylation is a mechanism by which cells lower their respiration in response to DNA damage. This raises the possibility that activation of DNA damage checkpoint mechanisms could contribute to aerobic fermentation (Warburg effect), a hallmark of cancer cells.
Collapse
Affiliation(s)
- Kobi J Simpson-Lavy
- University of Colorado School of Medicine, Department of Biochemistry and Molecular Genetics, 12801 E 17(th) Avenue, Aurora, CO 80045, USA; Tel Aviv University, Department of Molecular Microbiology and Biotechnology, Haim Levanon Street, Tel Aviv 6997801, Israel.
| | - Alex Bronstein
- Tel Aviv University, Department of Molecular Microbiology and Biotechnology, Haim Levanon Street, Tel Aviv 6997801, Israel
| | - Martin Kupiec
- Tel Aviv University, Department of Molecular Microbiology and Biotechnology, Haim Levanon Street, Tel Aviv 6997801, Israel
| | - Mark Johnston
- University of Colorado School of Medicine, Department of Biochemistry and Molecular Genetics, 12801 E 17(th) Avenue, Aurora, CO 80045, USA.
| |
Collapse
|
34
|
Nicastro R, Tripodi F, Gaggini M, Castoldi A, Reghellin V, Nonnis S, Tedeschi G, Coccetti P. Snf1 Phosphorylates Adenylate Cyclase and Negatively Regulates Protein Kinase A-dependent Transcription in Saccharomyces cerevisiae. J Biol Chem 2015; 290:24715-26. [PMID: 26309257 DOI: 10.1074/jbc.m115.658005] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Indexed: 11/06/2022] Open
Abstract
In eukaryotes, nutrient availability and metabolism are coordinated by sensing mechanisms and signaling pathways, which influence a broad set of cellular functions such as transcription and metabolic pathways to match environmental conditions. In yeast, PKA is activated in the presence of high glucose concentrations, favoring fast nutrient utilization, shutting down stress responses, and boosting growth. On the contrary, Snf1/AMPK is activated in the presence of low glucose or alternative carbon sources, thus promoting an energy saving program through transcriptional activation and phosphorylation of metabolic enzymes. The PKA and Snf1/AMPK pathways share common downstream targets. Moreover, PKA has been reported to negatively influence the activation of Snf1/AMPK. We report a new cross-talk mechanism with a Snf1-dependent regulation of the PKA pathway. We show that Snf1 and adenylate cyclase (Cyr1) interact in a nutrient-independent manner. Moreover, we identify Cyr1 as a Snf1 substrate and show that Snf1 activation state influences Cyr1 phosphorylation pattern, cAMP intracellular levels, and PKA-dependent transcription.
Collapse
Affiliation(s)
- Raffaele Nicastro
- From the Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy, SYSBIO, Centre of Systems Biology, 20126 Milan, Italy
| | - Farida Tripodi
- From the Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy, SYSBIO, Centre of Systems Biology, 20126 Milan, Italy
| | - Marco Gaggini
- From the Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy, SYSBIO, Centre of Systems Biology, 20126 Milan, Italy
| | - Andrea Castoldi
- From the Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy, SYSBIO, Centre of Systems Biology, 20126 Milan, Italy
| | - Veronica Reghellin
- From the Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy, SYSBIO, Centre of Systems Biology, 20126 Milan, Italy
| | - Simona Nonnis
- Dipartimento di Patologia Animale, Igiene e Sanità Pubblica Veterinaria-Biochemistry, University of Milano, 20133 Milan, Italy, and the Filarete Foundation, 20139 Milan, Italy
| | - Gabriella Tedeschi
- Dipartimento di Patologia Animale, Igiene e Sanità Pubblica Veterinaria-Biochemistry, University of Milano, 20133 Milan, Italy, and the Filarete Foundation, 20139 Milan, Italy
| | - Paola Coccetti
- From the Department of Biotechnology and Biosciences, University of Milano-Bicocca, 20126 Milan, Italy, SYSBIO, Centre of Systems Biology, 20126 Milan, Italy,
| |
Collapse
|
35
|
Abstract
Glucose is the primary source of energy for the budding yeast Saccharomyces cerevisiae. Although yeast cells can utilize a wide range of carbon sources, presence of glucose suppresses molecular activities involved in the use of alternate carbon sources as well as it represses respiration and gluconeogenesis. This dominant effect of glucose on yeast carbon metabolism is coordinated by several signaling and metabolic interactions that mainly regulate transcriptional activity but are also effective at post-transcriptional and post-translational levels. This review describes effects of glucose repression on yeast carbon metabolism with a focus on roles of the Snf3/Rgt2 glucose-sensing pathway and Snf1 signal transduction in establishment and relief of glucose repression. The role of Snf1 signaling in glucose repression and carbon metabolism in Saccharomyces cerevisae.
Collapse
Affiliation(s)
- Ömur Kayikci
- Department of Biology and Biological Engineering, Kemivägen 10, Chalmers University of Technology, SE41296 Gothenburg, Sweden Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, SE41296 Gothenburg, Sweden
| | - Jens Nielsen
- Department of Biology and Biological Engineering, Kemivägen 10, Chalmers University of Technology, SE41296 Gothenburg, Sweden Novo Nordisk Foundation Center for Biosustainability, Chalmers University of Technology, SE41296 Gothenburg, Sweden Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, DK2970 Hørsholm, Denmark
| |
Collapse
|
36
|
Rubio-Villena C, Sanz P, Garcia-Gimeno MA. Structure-Function Analysis of PPP1R3D, a Protein Phosphatase 1 Targeting Subunit, Reveals a Binding Motif for 14-3-3 Proteins which Regulates its Glycogenic Properties. PLoS One 2015; 10:e0131476. [PMID: 26114292 PMCID: PMC4482762 DOI: 10.1371/journal.pone.0131476] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 06/01/2015] [Indexed: 01/20/2023] Open
Abstract
Protein phosphatase 1 (PP1) is one of the major protein phosphatases in eukaryotic cells. It plays a key role in regulating glycogen synthesis, by dephosphorylating crucial enzymes involved in glycogen homeostasis such as glycogen synthase (GS) and glycogen phosphorylase (GP). To play this role, PP1 binds to specific glycogen targeting subunits that, on one hand recognize the substrates to be dephosphorylated and on the other hand recruit PP1 to glycogen particles. In this work we have analyzed the functionality of the different protein binding domains of one of these glycogen targeting subunits, namely PPP1R3D (R6) and studied how binding properties of different domains affect its glycogenic properties. We have found that the PP1 binding domain of R6 comprises a conserved RVXF motif (R102VRF) located at the N-terminus of the protein. We have also identified a region located at the C-terminus of R6 (W267DNND) that is involved in binding to the PP1 glycogenic substrates. Our results indicate that although binding to PP1 and glycogenic substrates are independent processes, impairment of any of them results in lack of glycogenic activity of R6. In addition, we have characterized a novel site of regulation in R6 that is involved in binding to 14-3-3 proteins (RARS74LP). We present evidence indicating that when binding of R6 to 14-3-3 proteins is prevented, R6 displays hyper-glycogenic activity although is rapidly degraded by the lysosomal pathway. These results define binding to 14-3-3 proteins as an additional pathway in the control of the glycogenic properties of R6.
Collapse
Affiliation(s)
- Carla Rubio-Villena
- Instituto de Biomedicina de Valencia, CSIC, and Centro de Investigación en Red de Enfermedades Raras (CIBERER), Jaime Roig 11, Valencia, Spain
| | - Pascual Sanz
- Instituto de Biomedicina de Valencia, CSIC, and Centro de Investigación en Red de Enfermedades Raras (CIBERER), Jaime Roig 11, Valencia, Spain
- * E-mail:
| | - Maria Adelaida Garcia-Gimeno
- Instituto de Biomedicina de Valencia, CSIC, and Centro de Investigación en Red de Enfermedades Raras (CIBERER), Jaime Roig 11, Valencia, Spain
| |
Collapse
|
37
|
Jiao R, Postnikoff S, Harkness TA, Arnason TG. The SNF1 Kinase Ubiquitin-associated Domain Restrains Its Activation, Activity, and the Yeast Life Span. J Biol Chem 2015; 290:15393-15404. [PMID: 25869125 DOI: 10.1074/jbc.m115.647032] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Indexed: 02/04/2023] Open
Abstract
The enzyme family of heterotrimeric AMP-dependent protein kinases is activated upon low energy states, conferring a switch toward energy-conserving metabolic pathways through immediate kinase actions on enzyme targets and delayed alterations in gene expression through its nuclear relocalization. This family is evolutionarily conserved, including the presence of a ubiquitin-associated (UBA) motif in most catalytic subunits. The potential for the UBA domain to promote protein associations or direct subcellular location, as seen in other UBA-containing proteins, led us to query whether the UBA domain within the yeast AMP-dependent protein kinase ortholog, SNF1 kinase, was important in these aspects of its regulation. Here, we demonstrate that conserved UBA motif mutations significantly alter SNF1 kinase activation and biological activity, including enhanced allosteric subunit associations and increased oxidative stress resistance and life span. Significantly, the enhanced UBA-dependent longevity and oxidative stress response are at least partially dependent on the Fkh1 and Fkh2 stress response transcription factors, which in turn are shown to influence Snf1 gene expression.
Collapse
Affiliation(s)
- Rubin Jiao
- Departments of Anatomy and Cell Biology and University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Spike Postnikoff
- Departments of Anatomy and Cell Biology and University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Troy A Harkness
- Departments of Anatomy and Cell Biology and University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Terra G Arnason
- Departments of Anatomy and Cell Biology and University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada; Medicine, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada.
| |
Collapse
|
38
|
DeMille D, Badal BD, Evans JB, Mathis AD, Anderson JF, Grose JH. PAS kinase is activated by direct SNF1-dependent phosphorylation and mediates inhibition of TORC1 through the phosphorylation and activation of Pbp1. Mol Biol Cell 2015; 26:569-82. [PMID: 25428989 PMCID: PMC4310746 DOI: 10.1091/mbc.e14-06-1088] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 10/29/2014] [Accepted: 11/16/2014] [Indexed: 01/22/2023] Open
Abstract
We describe the interplay between three sensory protein kinases in yeast: AMP-regulated kinase (AMPK, or SNF1 in yeast), PAS kinase 1 (Psk1 in yeast), and the target of rapamycin complex 1 (TORC1). This signaling cascade occurs through the SNF1-dependent phosphorylation and activation of Psk1, which phosphorylates and activates poly(A)- binding protein binding protein 1 (Pbp1), which then inhibits TORC1 through sequestration at stress granules. The SNF1-dependent phosphorylation of Psk1 appears to be direct, in that Snf1 is necessary and sufficient for Psk1 activation by alternate carbon sources, is required for altered Psk1 protein mobility, is able to phosphorylate Psk1 in vitro, and binds Psk1 via its substrate-targeting subunit Gal83. Evidence for the direct phosphorylation and activation of Pbp1 by Psk1 is also provided by in vitro and in vivo kinase assays, including the reduction of Pbp1 localization at distinct cytoplasmic foci and subsequent rescue of TORC1 inhibition in PAS kinase-deficient yeast. In support of this signaling cascade, Snf1-deficient cells display increased TORC1 activity, whereas cells containing hyperactive Snf1 display a PAS kinase-dependent decrease in TORC1 activity. This interplay between yeast SNF1, Psk1, and TORC1 allows for proper glucose allocation during nutrient depletion, reducing cell growth and proliferation when energy is low.
Collapse
Affiliation(s)
- Desiree DeMille
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602
| | - Bryan D Badal
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602
| | - J Brady Evans
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602
| | - Andrew D Mathis
- Department of Chemistry, Brigham Young University, Provo, UT 84602
| | - Joseph F Anderson
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602
| | - Julianne H Grose
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602
| |
Collapse
|
39
|
Stein K, Chiang HL. Exocytosis and Endocytosis of Small Vesicles across the Plasma Membrane in Saccharomyces cerevisiae. MEMBRANES 2014; 4:608-29. [PMID: 25192542 PMCID: PMC4194051 DOI: 10.3390/membranes4030608] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Revised: 08/02/2014] [Accepted: 08/18/2014] [Indexed: 12/14/2022]
Abstract
When Saccharomyces cerevisiae is starved of glucose, the gluconeogenic enzymes fructose-1,6-bisphosphatase (FBPase), phosphoenolpyruvate carboxykinase, isocitrate lyase, and malate dehydrogenase, as well as the non-gluconeogenic enzymes glyceraldehyde-3-phosphate dehydrogenase and cyclophilin A, are secreted into the periplasm. In the extracellular fraction, these secreted proteins are associated with small vesicles that account for more than 90% of the total number of extracellular structures observed. When glucose is added to glucose-starved cells, FBPase is internalized and associated with clusters of small vesicles in the cytoplasm. Specifically, the internalization of FBPase results in the decline of FBPase and vesicles in the extracellular fraction and their appearance in the cytoplasm. The clearance of extracellular vesicles and vesicle-associated proteins from the extracellular fraction is dependent on the endocytosis gene END3. This internalization is regulated when cells are transferred from low to high glucose. It is rapidly occurring and is a high capacity process, as clusters of vesicles occupy 10%–20% of the total volume in the cytoplasm in glucose re-fed cells. FBPase internalization also requires the VPS34 gene encoding PI3K. Following internalization, FBPase is delivered to the vacuole for degradation, whereas proteins that are not degraded may be recycled.
Collapse
Affiliation(s)
- Kathryn Stein
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA.
| | - Hui-Ling Chiang
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA.
| |
Collapse
|
40
|
Abstract
What has been will be again, what has been done will be done again; there is nothing new under the sun. -Ecclesiastes 1:9 (New International Version) Posttranscriptional regulation of gene expression has an important role in defining the phenotypic characteristics of an organism. Well-defined steps in mRNA metabolism that occur in the nucleus-capping, splicing, and polyadenylation-are mechanistically linked to the process of transcription. Recent evidence suggests another link between RNA polymerase II (Pol II) and a posttranscriptional process that occurs in the cytoplasm-mRNA decay. This conclusion appears to represent a conundrum. How could mRNA synthesis in the nucleus and mRNA decay in the cytoplasm be mechanistically linked? After a brief overview of mRNA processing, we will review the recent evidence for transcription-coupled mRNA decay and the possible involvement of Snf1, the Saccharomyces cerevisiae ortholog of AMP-activated protein kinase, in this process.
Collapse
|
41
|
Rødkaer SV, Faergeman NJ. Glucose- and nitrogen sensing and regulatory mechanisms inSaccharomyces cerevisiae. FEMS Yeast Res 2014; 14:683-96. [DOI: 10.1111/1567-1364.12157] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 04/11/2014] [Accepted: 04/13/2014] [Indexed: 11/29/2022] Open
Affiliation(s)
- Steven V. Rødkaer
- Villum Center for Bioanalytical Sciences; Department of Biochemistry and Molecular Biology; University of Southern Denmark; Odense M Denmark
| | - Nils J. Faergeman
- Villum Center for Bioanalytical Sciences; Department of Biochemistry and Molecular Biology; University of Southern Denmark; Odense M Denmark
| |
Collapse
|
42
|
Protein phosphatase PP1/GLC7 interaction domain in yeast eIF2γ bypasses targeting subunit requirement for eIF2α dephosphorylation. Proc Natl Acad Sci U S A 2014; 111:E1344-53. [PMID: 24706853 DOI: 10.1073/pnas.1400129111] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Whereas the protein kinases GCN2, HRI, PKR, and PERK specifically phosphorylate eukaryotic translation initiation factor 2 (eIF2α) on Ser51 to regulate global and gene-specific mRNA translation, eIF2α is dephosphorylated by the broadly acting serine/threonine protein phosphatase 1 (PP1). In mammalian cells, the regulatory subunits GADD34 and CReP target PP1 to dephosphorylate eIF2α; however, as there are no homologs of these targeting subunits in yeast, it is unclear how GLC7, the functional homolog of PP1 in yeast, is recruited to dephosphorylate eIF2α. Here, we show that a novel N-terminal extension on yeast eIF2γ contains a PP1-binding motif (KKVAF) that enables eIF2γ to pull down GLC7 and target it to dephosphorylate eIF2α. Truncation or point mutations designed to eliminate the KKVAF motif in eIF2γ impair eIF2α dephosphorylation in vivo and in vitro and enhance expression of GCN4. Replacement of the N terminus of eIF2γ with the GLC7-binding domain from GAC1 or fusion of heterologous dimerization domains to eIF2γ and GLC7, respectively, maintained eIF2α phosphorylation at basal levels. Taken together, these results indicate that, in contrast to the paradigm of distinct PP1-targeting or regulatory subunits, the unique N terminus of yeast eIF2γ functions in cis to target GLC7 to dephosphorylate eIF2α.
Collapse
|
43
|
Mutations in SNF1 complex genes affect yeast cell wall strength. Eur J Cell Biol 2013; 92:383-95. [DOI: 10.1016/j.ejcb.2014.01.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2013] [Revised: 12/19/2013] [Accepted: 01/02/2014] [Indexed: 01/01/2023] Open
|
44
|
Abstract
The AMP-activated protein kinase (AMPK) is a major stress sensor of mammalian cells. AMPK's homolog in the yeast Saccharomyces cerevisiae, the SNF1 protein kinase, is a central regulator of carbon metabolism that inhibits the Snf3/Rgt2-Rgt1 glucose sensing pathway and activates genes involved in respiration. We present evidence that glucose induces modification of the Snf1 catalytic subunt of SNF1 with the small ubiquitin-like modifier protein SUMO, catalyzed by the SUMO (E3) ligase Mms21. Our results suggest that SUMOylation of Snf1 inhibits its function in two ways: by interaction of SUMO attached to lysine 549 with a SUMO-interacting sequence motif located near the active site of Snf1, and by targeting Snf1 for destruction via the Slx5-Slx8 (SUMO-directed) ubiquitin ligase. These findings reveal another way SNF1 function is regulated in response to carbon source.
Collapse
|
45
|
Koivistoinen OM, Kuivanen J, Barth D, Turkia H, Pitkänen JP, Penttilä M, Richard P. Glycolic acid production in the engineered yeasts Saccharomyces cerevisiae and Kluyveromyces lactis. Microb Cell Fact 2013; 12:82. [PMID: 24053654 PMCID: PMC3850452 DOI: 10.1186/1475-2859-12-82] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2013] [Accepted: 09/15/2013] [Indexed: 11/24/2022] Open
Abstract
Background Glycolic acid is a C2 hydroxy acid that is a widely used chemical compound. It can be polymerised to produce biodegradable polymers with excellent gas barrier properties. Currently, glycolic acid is produced in a chemical process using fossil resources and toxic chemicals. Biotechnological production of glycolic acid using renewable resources is a desirable alternative. Results The yeasts Saccharomyces cerevisiae and Kluyveromyces lactis are suitable organisms for glycolic acid production since they are acid tolerant and can grow in the presence of up to 50 g l-1 glycolic acid. We engineered S. cerevisiae and K. lactis for glycolic acid production using the reactions of the glyoxylate cycle to produce glyoxylic acid and then reducing it to glycolic acid. The expression of a high affinity glyoxylate reductase alone already led to glycolic acid production. The production was further improved by deleting genes encoding malate synthase and the cytosolic form of isocitrate dehydrogenase. The engineered S. cerevisiae strain produced up to about 1 g l-1 of glycolic acid in a medium containing d-xylose and ethanol. Similar modifications in K. lactis resulted in a much higher glycolic acid titer. In a bioreactor cultivation with d-xylose and ethanol up to 15 g l-1 of glycolic acid was obtained. Conclusions This is the first demonstration of engineering yeast to produce glycolic acid. Prior to this work glycolic acid production through the glyoxylate cycle has only been reported in bacteria. The benefit of a yeast host is the possibility for glycolic acid production also at low pH, which was demonstrated in flask cultivations. Production of glycolic acid was first shown in S. cerevisiae. To test whether a Crabtree negative yeast would be better suited for glycolic acid production we engineered K. lactis in the same way and demonstrated it to be a better host for glycolic acid production.
Collapse
Affiliation(s)
- Outi M Koivistoinen
- VTT Technical Research Centre of Finland, Tietotie 2, Espoo FI-02044, P,O, Box 1000, VTT, Finland.
| | | | | | | | | | | | | |
Collapse
|
46
|
Ruiz A, Xu X, Carlson M. Ptc1 protein phosphatase 2C contributes to glucose regulation of SNF1/AMP-activated protein kinase (AMPK) in Saccharomyces cerevisiae. J Biol Chem 2013; 288:31052-8. [PMID: 24019512 DOI: 10.1074/jbc.m113.503763] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The SNF1/AMP-activated protein kinases (AMPKs) function in energy regulation in eukaryotic cells. SNF1/AMPKs are αβγ heterotrimers that are activated by phosphorylation of the activation loop Thr on the catalytic subunit. Protein kinases that activate SNF1/AMPK have been identified, but the protein phosphatases responsible for dephosphorylation of the activation loop are less well defined. For Saccharomyces cerevisiae SNF1/AMPK, Reg1-Glc7 protein phosphatase 1 and Sit4 type 2A-related phosphatase function together to dephosphorylate Thr-210 on the Snf1 catalytic subunit during growth on high concentrations of glucose; reg1Δ and sit4Δ single mutations do not impair dephosphorylation when inappropriate glycogen synthesis, also caused by these mutations, is blocked. We here present evidence that Ptc1 protein phosphatase 2C also has a role in dephosphorylation of Snf1 Thr-210 in vivo. The sit4Δ ptc1Δ mutant exhibited partial defects in regulation of the phosphorylation state of Snf1. The reg1Δ ptc1Δ mutant was viable only when expressing mutant Snf1 proteins with reduced kinase activity, and Thr-210 phosphorylation of the mutant SNF1 heterotrimers was substantially elevated during growth on high glucose. This evidence, together with findings on the reg1Δ sit4Δ mutant, indicates that although Reg1-Glc7 plays the major role, all three phosphatases contribute to maintenance of the Snf1 activation loop in the dephosphorylated state during growth on high glucose. Ptc1 has overlapping functions with Reg1-Glc7 and Sit4 in glucose regulation of SNF1/AMPK and cell viability.
Collapse
Affiliation(s)
- Amparo Ruiz
- From the Department of Genetics and Development, Columbia University, New York, New York 10032
| | | | | |
Collapse
|
47
|
Bergdahl B, Sandström AG, Borgström C, Boonyawan T, van Niel EWJ, Gorwa-Grauslund MF. Engineering yeast hexokinase 2 for improved tolerance toward xylose-induced inactivation. PLoS One 2013; 8:e75055. [PMID: 24040384 PMCID: PMC3765440 DOI: 10.1371/journal.pone.0075055] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2013] [Accepted: 08/05/2013] [Indexed: 11/21/2022] Open
Abstract
Hexokinase 2 (Hxk2p) from Saccharomyces cerevisiae is a bi-functional enzyme being both a catalyst and an important regulator in the glucose repression signal. In the presence of xylose Hxk2p is irreversibly inactivated through an autophosphorylation mechanism, affecting all functions. Consequently, the regulation of genes involved in sugar transport and fermentative metabolism is impaired. The aim of the study was to obtain new Hxk2p-variants, immune to the autophosphorylation, which potentially can restore the repressive capability closer to its nominal level. In this study we constructed the first condensed, rationally designed combinatorial library targeting the active-site in Hxk2p. We combined protein engineering and genetic engineering for efficient screening and identified a variant with Phe159 changed to tyrosine. This variant had 64% higher catalytic activity in the presence of xylose compared to the wild-type and is expected to be a key component for increasing the productivity of recombinant xylose-fermenting strains for bioethanol production from lignocellulosic feedstocks.
Collapse
Affiliation(s)
- Basti Bergdahl
- Division of Applied Microbiology, Department of Chemistry, Lund University, Lund, Sweden
- * E-mail:
| | - Anders G. Sandström
- Division of Applied Microbiology, Department of Chemistry, Lund University, Lund, Sweden
| | - Celina Borgström
- Division of Applied Microbiology, Department of Chemistry, Lund University, Lund, Sweden
| | - Tarinee Boonyawan
- Division of Applied Microbiology, Department of Chemistry, Lund University, Lund, Sweden
| | - Ed W. J. van Niel
- Division of Applied Microbiology, Department of Chemistry, Lund University, Lund, Sweden
| | | |
Collapse
|
48
|
Clement ST, Dixit G, Dohlman HG. Regulation of yeast G protein signaling by the kinases that activate the AMPK homolog Snf1. Sci Signal 2013; 6:ra78. [PMID: 24003255 DOI: 10.1126/scisignal.2004143] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Extracellular signals, such as nutrients and hormones, cue intracellular pathways to produce adaptive responses. Often, cells must coordinate their responses to multiple signals to produce an appropriate outcome. We showed that components of a glucose-sensing pathway acted on components of a heterotrimeric guanine nucleotide-binding protein (G protein)-mediated pheromone signaling pathway in the yeast Saccharomyces cerevisiae. We demonstrated that the G protein α subunit Gpa1 was phosphorylated in response to conditions of reduced glucose availability and that this phosphorylation event contributed to reduced pheromone-dependent stimulation of mitogen-activated protein kinases, gene transcription, cell morphogenesis, and mating efficiency. We found that Elm1, Sak1, and Tos3, the kinases that phosphorylate Snf1, the yeast homolog of adenosine monophosphate-activated protein kinase (AMPK), in response to limited glucose availability, also phosphorylated Gpa1 and contributed to the diminished mating response. Reg1, the regulatory subunit of the phosphatase PP1 that acts on Snf1, was likewise required to reverse the phosphorylation of Gpa1 and to maintain the mating response. Thus, the same kinases and phosphatase that regulate Snf1 also regulate Gpa1. More broadly, these results indicate that the pheromone signaling and glucose-sensing pathways communicate directly to coordinate cell behavior.
Collapse
Affiliation(s)
- Sarah T Clement
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | | | | |
Collapse
|
49
|
Yang S, Guarnieri MT, Smolinski S, Ghirardi M, Pienkos PT. De novo transcriptomic analysis of hydrogen production in the green alga Chlamydomonas moewusii through RNA-Seq. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:118. [PMID: 23971877 PMCID: PMC3846465 DOI: 10.1186/1754-6834-6-118] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 08/05/2013] [Indexed: 05/04/2023]
Abstract
BACKGROUND Microalgae can make a significant contribution towards meeting global renewable energy needs in both carbon-based and hydrogen (H2) biofuel. The development of energy-related products from algae could be accelerated with improvements in systems biology tools, and recent advances in sequencing technology provide a platform for enhanced transcriptomic analyses. However, these techniques are still heavily reliant upon available genomic sequence data. Chlamydomonas moewusii is a unicellular green alga capable of evolving molecular H2 under both dark and light anaerobic conditions, and has high hydrogenase activity that can be rapidly induced. However, to date, there is no systematic investigation of transcriptomic profiling during induction of H2 photoproduction in this organism. RESULTS In this work, RNA-Seq was applied to investigate transcriptomic profiles during the dark anaerobic induction of H2 photoproduction. 156 million reads generated from 7 samples were then used for de novo assembly after data trimming. BlastX results against NCBI database and Blast2GO results were used to interpret the functions of the assembled 34,136 contigs, which were then used as the reference contigs for RNA-Seq analysis. Our results indicated that more contigs were differentially expressed during the period of early and higher H2 photoproduction, and fewer contigs were differentially expressed when H2-photoproduction rates decreased. In addition, C. moewusii and C. reinhardtii share core functional pathways, and transcripts for H2 photoproduction and anaerobic metabolite production were identified in both organisms. C. moewusii also possesses similar metabolic flexibility as C. reinhardtii, and the difference between C. moewusii and C. reinhardtii on hydrogenase expression and anaerobic fermentative pathways involved in redox balancing may explain their different profiles of hydrogenase activity and secreted anaerobic metabolites. CONCLUSIONS Herein, we have described a workflow using commercial software to analyze RNA-Seq data without reference genome sequence information, which can be applied to other unsequenced microorganisms. This study provided biological insights into the anaerobic fermentation and H2 photoproduction of C. moewusii, and the first transcriptomic RNA-Seq dataset of C. moewusii generated in this study also offer baseline data for further investigation (e.g. regulatory proteins related to fermentative pathway discussed in this study) of this organism as a H2-photoproduction strain.
Collapse
Affiliation(s)
| | | | - Sharon Smolinski
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Maria Ghirardi
- Biosciences Center, National Renewable Energy Laboratory, Golden, CO 80401, USA
| | | |
Collapse
|
50
|
Kim JH, Roy A, Jouandot D, Cho KH. The glucose signaling network in yeast. Biochim Biophys Acta Gen Subj 2013; 1830:5204-10. [PMID: 23911748 DOI: 10.1016/j.bbagen.2013.07.025] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2013] [Revised: 07/24/2013] [Accepted: 07/26/2013] [Indexed: 01/26/2023]
Abstract
BACKGROUND Most cells possess a sophisticated mechanism for sensing glucose and responding to it appropriately. Glucose sensing and signaling in the budding yeast Saccharomyces cerevisiae represent an important paradigm for understanding how extracellular signals lead to changes in the gene expression program in eukaryotes. SCOPE OF REVIEW This review focuses on the yeast glucose sensing and signaling pathways that operate in a highly regulated and cooperative manner to bring about glucose-induction of HXT gene expression. MAJOR CONCLUSIONS The yeast cells possess a family of glucose transporters (HXTs), with different kinetic properties. They employ three major glucose signaling pathways-Rgt2/Snf3, AMPK, and cAMP-PKA-to express only those transporters best suited for the amounts of glucose available. We discuss the current understanding of how these pathways are integrated into a regulatory network to ensure efficient uptake and utilization of glucose. GENERAL SIGNIFICANCE Elucidating the role of multiple glucose signals and pathways involved in glucose uptake and metabolism in yeast may reveal the molecular basis of glucose homeostasis in humans, especially under pathological conditions, such as hyperglycemia in diabetics and the elevated rate of glycolysis observed in many solid tumors.
Collapse
Affiliation(s)
- Jeong-Ho Kim
- Department of Biochemistry and Molecular Medicine, The George Washington University Medical Center, 2300 Eye Street, Washington, DC 20037, USA.
| | | | | | | |
Collapse
|