1
|
Li F, Wang CY, Wu YC, Zhang MY, Wang YJ, Zhou XY, Zhang YX. Enhancing the biosynthesis of 2-keto-L-gulonic acid through multi-strategy metabolic engineering in Pseudomonas putida KT2440. BIORESOURCE TECHNOLOGY 2024; 392:130014. [PMID: 37956951 DOI: 10.1016/j.biortech.2023.130014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 11/09/2023] [Accepted: 11/10/2023] [Indexed: 11/19/2023]
Abstract
2-KGA, a precursor for the synthesis of Vitamin C, is currently produced in China utilizing the "two-step fermentation" technique. Nevertheless, this method exhibits many inherent constraints. This study presents a comprehensive metabolic engineering strategy to establish and optimize a one-step 2-KGA fermentation process from D-sorbitol in Pseudomonas putida KT2440. In general, the endogenous promoters were screened to identify promoter P1 for subsequent heterologous gene expression in KT2440. Following the screening and confirmation of suitable heterologous gene elements such as sldh, sdh, cytc551, pqqAB, and irrE, genetic recombination was performed in KT2440. In comparison to the initial achievement of expressing only sldh and sdh in KT2440, a yield of merely 0.42 g/L was obtained. However, by implementing four metabolic engineering strategies, the recombinant strain KT20 exhibited a significant enhancement in its ability to produce 2-KGA with a remarkable yield of up to 6.5 g/L - representing an impressive 15.48-fold improvement.
Collapse
Affiliation(s)
- Fan Li
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Cai-Yun Wang
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Ying-Cai Wu
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Meng-Yue Zhang
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Yi-Jin Wang
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China
| | - Xun-Yong Zhou
- Sinobiotech (Shenzhen) Limited Company, Shenzhen 518001, People's Republic of China
| | - Yi-Xuan Zhang
- School of Life Science and Biopharmaceutics, Shenyang Pharmaceutical University, Shenyang 110016, People's Republic of China.
| |
Collapse
|
2
|
Gutiérrez-Santiago F, Navarro F. Transcription by the Three RNA Polymerases under the Control of the TOR Signaling Pathway in Saccharomyces cerevisiae. Biomolecules 2023; 13:biom13040642. [PMID: 37189389 DOI: 10.3390/biom13040642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/30/2023] [Accepted: 04/02/2023] [Indexed: 04/05/2023] Open
Abstract
Ribosomes are the basis for protein production, whose biogenesis is essential for cells to drive growth and proliferation. Ribosome biogenesis is highly regulated in accordance with cellular energy status and stress signals. In eukaryotic cells, response to stress signals and the production of newly-synthesized ribosomes require elements to be transcribed by the three RNA polymerases (RNA pols). Thus, cells need the tight coordination of RNA pols to adjust adequate components production for ribosome biogenesis which depends on environmental cues. This complex coordination probably occurs through a signaling pathway that links nutrient availability with transcription. Several pieces of evidence strongly support that the Target of Rapamycin (TOR) pathway, conserved among eukaryotes, influences the transcription of RNA pols through different mechanisms to ensure proper ribosome components production. This review summarizes the connection between TOR and regulatory elements for the transcription of each RNA pol in the budding yeast Saccharomyces cerevisiae. It also focuses on how TOR regulates transcription depending on external cues. Finally, it discusses the simultaneous coordination of the three RNA pols through common factors regulated by TOR and summarizes the most important similarities and differences between S. cerevisiae and mammals.
Collapse
Affiliation(s)
- Francisco Gutiérrez-Santiago
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain
| | - Francisco Navarro
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain
- Centro de Estudios Avanzados en Aceite de Oliva y Olivar, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain
| |
Collapse
|
3
|
Galati E, Bosio MC, Novarina D, Chiara M, Bernini GM, Mozzarelli AM, García-Rubio ML, Gómez-González B, Aguilera A, Carzaniga T, Todisco M, Bellini T, Nava GM, Frigè G, Sertic S, Horner DS, Baryshnikova A, Manzari C, D'Erchia AM, Pesole G, Brown GW, Muzi-Falconi M, Lazzaro F. VID22 counteracts G-quadruplex-induced genome instability. Nucleic Acids Res 2021; 49:12785-12804. [PMID: 34871443 PMCID: PMC8682794 DOI: 10.1093/nar/gkab1156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 10/19/2021] [Accepted: 11/08/2021] [Indexed: 12/17/2022] Open
Abstract
Genome instability is a condition characterized by the accumulation of genetic alterations and is a hallmark of cancer cells. To uncover new genes and cellular pathways affecting endogenous DNA damage and genome integrity, we exploited a Synthetic Genetic Array (SGA)-based screen in yeast. Among the positive genes, we identified VID22, reported to be involved in DNA double-strand break repair. vid22Δ cells exhibit increased levels of endogenous DNA damage, chronic DNA damage response activation and accumulate DNA aberrations in sequences displaying high probabilities of forming G-quadruplexes (G4-DNA). If not resolved, these DNA secondary structures can block the progression of both DNA and RNA polymerases and correlate with chromosome fragile sites. Vid22 binds to and protects DNA at G4-containing regions both in vitro and in vivo. Loss of VID22 causes an increase in gross chromosomal rearrangement (GCR) events dependent on G-quadruplex forming sequences. Moreover, the absence of Vid22 causes defects in the correct maintenance of G4-DNA rich elements, such as telomeres and mtDNA, and hypersensitivity to the G4-stabilizing ligand TMPyP4. We thus propose that Vid22 is directly involved in genome integrity maintenance as a novel regulator of G4 metabolism.
Collapse
Affiliation(s)
- Elena Galati
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Maria C Bosio
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Daniele Novarina
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Matteo Chiara
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy.,Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari, Consiglio Nazionale delle Ricerche, Bari, Italy
| | - Giulia M Bernini
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Alessandro M Mozzarelli
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Maria L García-Rubio
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, Seville, Spain
| | - Belén Gómez-González
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, Seville, Spain
| | - Andrés Aguilera
- Centro Andaluz de Biología Molecular y Medicina Regenerativa-CABIMER, Universidad de Sevilla, Seville, Spain
| | - Thomas Carzaniga
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, via Vanvitelli 32, 20129 Milan, Italy
| | - Marco Todisco
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, via Vanvitelli 32, 20129 Milan, Italy
| | - Tommaso Bellini
- Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, via Vanvitelli 32, 20129 Milan, Italy
| | - Giulia M Nava
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Gianmaria Frigè
- Department of Experimental Oncology, IEO, European Institute of Oncology IRCCS, Via Adamello 16, 20139 Milan, Italy
| | - Sarah Sertic
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - David S Horner
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy.,Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari, Consiglio Nazionale delle Ricerche, Bari, Italy
| | - Anastasia Baryshnikova
- Department of Molecular Genetics and Donnelly Centre, University of Toronto, Toronto, Canada
| | - Caterina Manzari
- Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari, Consiglio Nazionale delle Ricerche, Bari, Italy
| | - Anna M D'Erchia
- Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari, Consiglio Nazionale delle Ricerche, Bari, Italy.,Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università di Bari 'A. Moro', Bari, Italy
| | - Graziano Pesole
- Istituto di Biomembrane, Bioenergetica e Biotecnologie Molecolari, Consiglio Nazionale delle Ricerche, Bari, Italy.,Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università di Bari 'A. Moro', Bari, Italy
| | - Grant W Brown
- Department of Biochemistry and Donnelly Centre, University of Toronto, Ontario M5S 3E1, Toronto, Canada
| | - Marco Muzi-Falconi
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| | - Federico Lazzaro
- Department of Biosciences, Università degli Studi di Milano, Via Celoria 26, 20133 Milan, Italy
| |
Collapse
|
4
|
Hernández-Hernández G, Vera-Salazar LA, Castanedo L, López-Fuentes E, Gutiérrez-Escobedo G, De Las Peñas A, Castaño I. Abf1 Is an Essential Protein That Participates in Cell Cycle Progression and Subtelomeric Silencing in Candida glabrata. J Fungi (Basel) 2021; 7:jof7121005. [PMID: 34946988 PMCID: PMC8708972 DOI: 10.3390/jof7121005] [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: 10/19/2021] [Revised: 11/09/2021] [Accepted: 11/12/2021] [Indexed: 12/02/2022] Open
Abstract
Accurate DNA replication and segregation is key to reproduction and cell viability in all organisms. Autonomously replicating sequence-binding factor 1 (Abf1) is a multifunctional protein that has essential roles in replication, transcription, and regional silencing in the model yeast Saccharomyces cerevisiae. In the opportunistic pathogenic fungus Candida glabrata, which is closely related to S. cerevisiae, these processes are important for survival within the host, for example, the regulation of transcription of virulence-related genes like those involved in adherence. Here, we describe that CgABF1 is an essential gene required for cell viability and silencing near the telomeres, where many adhesin-encoding genes reside. CgAbf1 mediated subtelomeric silencing depends on the 43 C-terminal amino acids. We also found that abnormal expression, depletion, or overexpression of Abf1, results in defects in nuclear morphology, nuclear segregation, and transit through the cell cycle. In the absence of ABF1, cells are arrested in G2 but start cycling again after 9 h, coinciding with the loss of cell viability and the appearance of cells with higher DNA content. Overexpression of CgABF1 causes defects in nuclear segregation and cell cycle progression. We suggest that these effects could be due to the deregulation of DNA replication.
Collapse
Affiliation(s)
- Grecia Hernández-Hernández
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), Camino a la Presa San José No. 2055 Col. Lomas 4 Sección, San Luis Potosí CP 78233, Mexico; (G.H.-H.); (L.A.V.-S.); (G.G.-E.); (A.D.L.P.)
| | - Laura A. Vera-Salazar
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), Camino a la Presa San José No. 2055 Col. Lomas 4 Sección, San Luis Potosí CP 78233, Mexico; (G.H.-H.); (L.A.V.-S.); (G.G.-E.); (A.D.L.P.)
| | - Leonardo Castanedo
- Department of Plant Physiology, Faculty of Biology and Biotechnology, Ruhr University Bochum, Universitätsstrasse, 150 ND3/30, D-44801 Bochum, Germany;
| | - Eunice López-Fuentes
- Division of Hematology and Oncology, Department of Pediatrics, University of California, San Francisco, CA 94158, USA;
| | - Guadalupe Gutiérrez-Escobedo
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), Camino a la Presa San José No. 2055 Col. Lomas 4 Sección, San Luis Potosí CP 78233, Mexico; (G.H.-H.); (L.A.V.-S.); (G.G.-E.); (A.D.L.P.)
| | - Alejandro De Las Peñas
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), Camino a la Presa San José No. 2055 Col. Lomas 4 Sección, San Luis Potosí CP 78233, Mexico; (G.H.-H.); (L.A.V.-S.); (G.G.-E.); (A.D.L.P.)
| | - Irene Castaño
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica (IPICYT), Camino a la Presa San José No. 2055 Col. Lomas 4 Sección, San Luis Potosí CP 78233, Mexico; (G.H.-H.); (L.A.V.-S.); (G.G.-E.); (A.D.L.P.)
- Correspondence: ; Tel.: +52-444-834-2038
| |
Collapse
|
5
|
Rico-Díaz A, Barreiro-Alonso A, Rey-Souto C, Becerra M, Lamas-Maceiras M, Cerdán ME, Vizoso-Vázquez Á. The HMGB Protein KlIxr1, a DNA Binding Regulator of Kluyveromyces lactis Gene Expression Involved in Oxidative Metabolism, Growth, and dNTP Synthesis. Biomolecules 2021; 11:biom11091392. [PMID: 34572607 PMCID: PMC8465852 DOI: 10.3390/biom11091392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 09/10/2021] [Accepted: 09/16/2021] [Indexed: 12/15/2022] Open
Abstract
In the traditional fermentative model yeast Saccharomyces cerevisiae, ScIxr1 is an HMGB (High Mobility Group box B) protein that has been considered as an important regulator of gene transcription in response to external changes like oxygen, carbon source, or nutrient availability. Kluyveromyces lactis is also a useful eukaryotic model, more similar to many human cells due to its respiratory metabolism. We cloned and functionally characterized by different methodologies KlIXR1, which encodes a protein with only 34.4% amino acid sequence similarity to ScIxr1. Our data indicate that both proteins share common functions, including their involvement in the response to hypoxia or oxidative stress induced by hydrogen peroxide or metal treatments, as well as in the control of key regulators for maintenance of the dNTP (deoxyribonucleotide triphosphate) pool and ribosome synthesis. KlIxr1 is able to bind specific regulatory DNA sequences in the promoter of its target genes, which are well conserved between S. cerevisiae and K. lactis. Oppositely, we found important differences between ScIrx1 and KlIxr1 affecting cellular responses to cisplatin or cycloheximide in these yeasts, which could be dependent on specific and non-conserved domains present in these two proteins.
Collapse
|
6
|
Transcriptional control of ribosome biogenesis in yeast: links to growth and stress signals. Biochem Soc Trans 2021; 49:1589-1599. [PMID: 34240738 PMCID: PMC8421047 DOI: 10.1042/bst20201136] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/14/2021] [Accepted: 06/18/2021] [Indexed: 12/15/2022]
Abstract
Ribosome biogenesis requires prodigious transcriptional output in rapidly growing yeast cells and is highly regulated in response to both growth and stress signals. This minireview focuses on recent developments in our understanding of this regulatory process, with an emphasis on the 138 ribosomal protein genes (RPGs) themselves and a group of >200 ribosome biogenesis (RiBi) genes whose products contribute to assembly but are not part of the ribosome. Expression of most RPGs depends upon Rap1, a pioneer transcription factor (TF) required for the binding of a pair of RPG-specific TFs called Fhl1 and Ifh1. RPG expression is correlated with Ifh1 promoter binding, whereas Rap1 and Fhl1 remain promoter-associated upon stress-induced down regulation. A TF called Sfp1 has also been implicated in RPG regulation, though recent work reveals that its primary function is in activation of RiBi and other growth-related genes. Sfp1 plays an important regulatory role at a small number of RPGs where Rap1–Fhl1–Ifh1 action is subsidiary or non-existent. In addition, nearly half of all RPGs are bound by Hmo1, which either stabilizes or re-configures Fhl1–Ifh1 binding. Recent studies identified the proline rotamase Fpr1, known primarily for its role in rapamycin-mediated inhibition of the TORC1 kinase, as an additional TF at RPG promoters. Fpr1 also affects Fhl1–Ifh1 binding, either independently or in cooperation with Hmo1. Finally, a major recent development was the discovery of a protein homeostasis mechanism driven by unassembled ribosomal proteins, referred to as the Ribosome Assembly Stress Response (RASTR), that controls RPG transcription through the reversible condensation of Ifh1.
Collapse
|
7
|
Zencir S, Dilg D, Rueda MP, Shore D, Albert B. Mechanisms coordinating ribosomal protein gene transcription in response to stress. Nucleic Acids Res 2020; 48:11408-11420. [PMID: 33084907 PMCID: PMC7672434 DOI: 10.1093/nar/gkaa852] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 09/17/2020] [Accepted: 10/11/2020] [Indexed: 11/14/2022] Open
Abstract
While expression of ribosomal protein genes (RPGs) in the budding yeast has been extensively studied, a longstanding enigma persists regarding their co-regulation under fluctuating growth conditions. Most RPG promoters display one of two distinct arrangements of a core set of transcription factors (TFs) and are further differentiated by the presence or absence of the HMGB protein Hmo1. However, a third group of promoters appears not to be bound by any of these proteins, raising the question of how the whole suite of genes is co-regulated. We demonstrate here that all RPGs are regulated by two distinct, but complementary mechanisms driven by the TFs Ifh1 and Sfp1, both of which are required for maximal expression in optimal conditions and coordinated downregulation upon stress. At the majority of RPG promoters, Ifh1-dependent regulation predominates, whereas Sfp1 plays the major role at all other genes. We also uncovered an unexpected protein homeostasis-dependent binding property of Hmo1 at RPG promoters. Finally, we show that the Ifh1 paralog Crf1, previously described as a transcriptional repressor, can act as a constitutive RPG activator. Our study provides a more complete picture of RPG regulation and may serve as a paradigm for unravelling RPG regulation in multicellular eukaryotes.
Collapse
Affiliation(s)
- Sevil Zencir
- Department of Molecular Biology and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 30 quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Daniel Dilg
- Department of Molecular Biology and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 30 quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Maria Paula Rueda
- Department of Molecular Biology and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 30 quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - David Shore
- Department of Molecular Biology and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 30 quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| | - Benjamin Albert
- Department of Molecular Biology and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 30 quai Ernest-Ansermet, 1211 Geneva 4, Switzerland
| |
Collapse
|
8
|
Dhillon N, Shelansky R, Townshend B, Jain M, Boeger H, Endy D, Kamakaka R. Permutational analysis of Saccharomyces cerevisiae regulatory elements. Synth Biol (Oxf) 2020; 5:ysaa007. [PMID: 32775697 PMCID: PMC7402160 DOI: 10.1093/synbio/ysaa007] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/12/2020] [Accepted: 05/29/2020] [Indexed: 01/24/2023] Open
Abstract
Gene expression in Saccharomyces cerevisiae is regulated at multiple levels. Genomic and epigenomic mapping of transcription factors and chromatin factors has led to the delineation of various modular regulatory elements—enhancers (upstream activating sequences), core promoters, 5′ untranslated regions (5′ UTRs) and transcription terminators/3′ untranslated regions (3′ UTRs). However, only a few of these elements have been tested in combinations with other elements and the functional interactions between the different modular regulatory elements remain under explored. We describe a simple and rapid approach to build a combinatorial library of regulatory elements and have used this library to study 26 different enhancers, core promoters, 5′ UTRs and transcription terminators/3′ UTRs to estimate the contribution of individual regulatory parts in gene expression. Our combinatorial analysis shows that while enhancers initiate gene expression, core promoters modulate the levels of enhancer-mediated expression and can positively or negatively affect expression from even the strongest enhancers. Principal component analysis (PCA) indicates that enhancer and promoter function can be explained by a single principal component while UTR function involves multiple functional components. The PCA also highlights outliers and suggest differences in mechanisms of regulation by individual elements. Our data also identify numerous regulatory cassettes composed of different individual regulatory elements that exhibit equivalent gene expression levels. These data thus provide a catalog of elements that could in future be used in the design of synthetic regulatory circuits.
Collapse
Affiliation(s)
- Namrita Dhillon
- Department of MCD Biology, University of California, Santa Cruz, CA, USA
| | - Robert Shelansky
- Department of MCD Biology, University of California, Santa Cruz, CA, USA
| | - Brent Townshend
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Miten Jain
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA, USA
| | - Hinrich Boeger
- Department of MCD Biology, University of California, Santa Cruz, CA, USA
| | - Drew Endy
- Department of Bioengineering, Stanford University, Stanford, CA, USA
| | - Rohinton Kamakaka
- Department of MCD Biology, University of California, Santa Cruz, CA, USA
| |
Collapse
|
9
|
Savic N, Shortill SP, Bilenky M, Dobbs JM, Dilworth D, Hirst M, Nelson CJ. Histone Chaperone Paralogs Have Redundant, Cooperative, and Divergent Functions in Yeast. Genetics 2019; 213:1301-1316. [PMID: 31604797 PMCID: PMC6893378 DOI: 10.1534/genetics.119.302235] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Accepted: 10/03/2019] [Indexed: 01/03/2023] Open
Abstract
Gene duplications increase organismal robustness by providing freedom for gene divergence or by increasing gene dosage. The yeast histone chaperones Fpr3 and Fpr4 are paralogs that can assemble nucleosomes in vitro; however, the genomic locations they target and their functional relationship is poorly understood. We refined the yeast synthetic genetic array approach to enable the functional dissection of gene paralogs. Applying this method to Fpr3 and Fpr4 uncovered redundant, cooperative, and divergent functions. While Fpr3 is uniquely involved in chromosome segregation, Fpr3 and Fpr4 cooperate to regulate genes involved in polyphosphate metabolism and ribosome biogenesis. We find that the TRAMP5 RNA exosome is critical for fitness in Δfpr3Δfpr4 yeast and leverage this information to identify an important role for Fpr4 at the 5' ends of protein coding genes. Additionally, Fpr4 and TRAMP5 negatively regulate RNAs from the nontranscribed spacers of ribosomal DNA. Yeast lacking Fpr3 and Fpr4 exhibit a genome instability phenotype at the ribosomal DNA, which implies that these histone chaperones regulate chromatin structure and DNA access at this location. Taken together. we provide genetic and transcriptomic evidence that Fpr3 and Fpr4 operate separately, cooperatively, and redundantly to regulate a variety of chromatin environments.
Collapse
Affiliation(s)
- Neda Savic
- Department Biochemistry and Microbiology, University of Victoria, BC V8W 3P6, Canada
| | - Shawn P Shortill
- Department Biochemistry and Microbiology, University of Victoria, BC V8W 3P6, Canada
| | - Misha Bilenky
- BC Cancer Agency Genome Sciences Centre and the Department of Microbiology & Immunology, Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Joseph M Dobbs
- Department Biochemistry and Microbiology, University of Victoria, BC V8W 3P6, Canada
| | - David Dilworth
- Department Biochemistry and Microbiology, University of Victoria, BC V8W 3P6, Canada
| | - Martin Hirst
- BC Cancer Agency Genome Sciences Centre and the Department of Microbiology & Immunology, Michael Smith Laboratories, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Christopher J Nelson
- Department Biochemistry and Microbiology, University of Victoria, BC V8W 3P6, Canada
| |
Collapse
|
10
|
Ren Y, Ay A, Dobra A, Kahveci T. Characterizing building blocks of resource constrained biological networks. BMC Bioinformatics 2019; 20:318. [PMID: 31216986 PMCID: PMC6584510 DOI: 10.1186/s12859-019-2838-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Background Identification of motifs–recurrent and statistically significant patterns–in biological networks is the key to understand the design principles, and to infer governing mechanisms of biological systems. This, however, is a computationally challenging task. This task is further complicated as biological interactions depend on limited resources, i.e., a reaction takes place if the reactant molecule concentrations are above a certain threshold level. This biochemical property implies that network edges can participate in a limited number of motifs simultaneously. Existing motif counting methods ignore this problem. This simplification often leads to inaccurate motif counts (over- or under-estimates), and thus, wrong biological interpretations. Results In this paper, we develop a novel motif counting algorithm, Partially Overlapping MOtif Counting (POMOC), that considers capacity levels for all interactions in counting motifs. Conclusions Our experiments on real and synthetic networks demonstrate that motif count using the POMOC method significantly differs from the existing motif counting approaches, and our method extends to large-scale biological networks in practical time. Our results also show that our method makes it possible to characterize the impact of different stress factors on cell’s organization of network. In this regard, analysis of a S. cerevisiae transcriptional regulatory network using our method shows that oxidative stress is more disruptive to organization and abundance of motifs in this network than mutations of individual genes. Our analysis also suggests that by focusing on the edges that lead to variation in motif counts, our method can be used to find important genes, and to reveal subtle topological and functional differences of the biological networks under different cell states.
Collapse
Affiliation(s)
- Yuanfang Ren
- Computer and Information Science and Engineering, University of Florida, Gainesville, 32611, FL, USA
| | - Ahmet Ay
- Departments of Biology and Mathematics, Colgate University, Hamilton, 13346, NY, USA
| | - Alin Dobra
- Computer and Information Science and Engineering, University of Florida, Gainesville, 32611, FL, USA
| | - Tamer Kahveci
- Computer and Information Science and Engineering, University of Florida, Gainesville, 32611, FL, USA.
| |
Collapse
|
11
|
Bakshi A, Moin M, Madhav MS, Kirti PB. Target of rapamycin, a master regulator of multiple signalling pathways and a potential candidate gene for crop improvement. PLANT BIOLOGY (STUTTGART, GERMANY) 2019; 21:190-205. [PMID: 30411830 DOI: 10.1111/plb.12935] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 11/05/2018] [Indexed: 06/08/2023]
Abstract
The target of rapamycin (TOR) protein regulates growth and development in photosynthetic and non-photosynthetic eukaryotes. Although the TOR regulatory networks are involved in nutrient and energy signalling, and transcriptional and translational control of multiple signalling pathways, the molecular mechanism of TOR regulation of plant abiotic stress responses is still unclear. The TOR-mediated transcriptional regulation of genes encoding ribosomal proteins (RP) is a necessity under stress conditions for balanced growth and productivity in plants. The activation of SnRKs (sucrose non-fermenting-related kinases) and the inactivation of TOR signalling in abiotic stresses is in line with the accumulation of ABA and transcriptional activation of stress responsive genes. Autophagy is induced under abiotic stress conditions, which results in degradation of proteins and the release of amino acids, which might possibly induce phosphorylation of TOR and, hence, its activation. TOR signalling also has a role in regulating ABA biosynthesis for transcriptional regulation of stress-related genes. The switch between activation and inactivation of TOR by its phosphorylation and de-phosphorylation maintains balanced growth in response to stresses. In the present review, we discuss the important signalling pathways that are regulated by TOR and try to assess the relationship between TOR signalling and tolerance to abiotic stresses in plants. The review also discusses possible cross-talk between TOR and RP genes in response to abiotic stresses.
Collapse
Affiliation(s)
- A Bakshi
- Department of Plant Sciences, University of Hyderabad, Hyderabad, India
| | - M Moin
- Department of Biotechnology, Indian Institute of Rice Research, Hyderabad, India
| | - M S Madhav
- Department of Biotechnology, Indian Institute of Rice Research, Hyderabad, India
| | - P B Kirti
- Department of Plant Sciences, University of Hyderabad, Hyderabad, India
| |
Collapse
|
12
|
Aw R, Polizzi KM. Biosensor‐assisted engineering of a high‐yield
Pichia pastoris
cell‐free protein synthesis platform. Biotechnol Bioeng 2019; 116:656-666. [DOI: 10.1002/bit.26901] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 10/12/2018] [Accepted: 12/14/2018] [Indexed: 12/12/2022]
Affiliation(s)
- Rochelle Aw
- Department of Chemical EngineeringImperial College LondonLondon UK
- Imperial College Centre for Synthetic Biology, Imperial College LondonLondon UK
| | - Karen M. Polizzi
- Department of Chemical EngineeringImperial College LondonLondon UK
- Imperial College Centre for Synthetic Biology, Imperial College LondonLondon UK
| |
Collapse
|
13
|
Systematic Identification, Characterization, and Conservation of Adjacent-Gene Coregulation in the Budding Yeast Saccharomyces cerevisiae. mSphere 2018; 3:3/3/e00220-18. [PMID: 29898982 PMCID: PMC6001612 DOI: 10.1128/msphere.00220-18] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 05/23/2018] [Indexed: 12/28/2022] Open
Abstract
The spatial positioning of genes throughout the genome arrangement can alter their expression in many eukaryotic organisms. Often this results in a genomic context-specific effect on transcription. One example of this is through the clustering of functionally related genes, which results in adjacent-gene coregulation in the budding yeast Saccharomyces cerevisiae. In the present study, we set out to systematically characterize the prevalence of this phenomenon, finding the genomic organization of functionally related genes into clusters is a characteristic of myriad gene families. These arrangements are found in many evolutionarily divergent fungi and thus represent a widespread, yet underappreciated, layer of transcriptional regulation. It is essential that cells orchestrate gene expression for the specific niche that they occupy, and this often requires coordination of the expression of large sets of genes. There are multiple regulatory systems that exist for modulation of gene expression, including the adjacent-gene coregulation of the rRNA and ribosome biogenesis and ribosomal protein families. Both gene families exhibit a nonrandom genomic distribution, often clustered directly adjacent to another member of the same family, which results in a tighter transcriptional coordination among adjacent paired genes than that of the unpaired genes within each regulon and can result in a shared promoter that coordinates expression of the pairs. This nonrandom genomic distribution has been seen in a few functionally related gene families, and many of these functional pairings are conserved across divergent fungal lineages. To date, the significance of these observations has not been extended in a systematic way to characterize how prevalent the role of adjacent-gene coregulation is in transcriptional regulation. In the present study, we systematically analyzed the transcriptional coherence of the functional pairs compared to the singletons within all gene families defined by the Gene Ontology Slim designation, using Saccharomyces cerevisiae as a model system, finding that clusters exhibit a tighter transcriptional correlation under specific contexts. We found that the longer a functional pairing is conserved the tighter its response to broad stress and nutritional responses, that roughly 25% of gene families exhibit a nonrandom genomic distribution, and that many of these clusters are conserved. This suggests that adjacent-gene coregulation is a widespread, yet underappreciated, transcriptional mechanism. IMPORTANCE The spatial positioning of genes throughout the genome arrangement can alter their expression in many eukaryotic organisms. Often this results in a genomic context-specific effect on transcription. One example of this is through the clustering of functionally related genes, which results in adjacent-gene coregulation in the budding yeast Saccharomyces cerevisiae. In the present study, we set out to systematically characterize the prevalence of this phenomenon, finding the genomic organization of functionally related genes into clusters is a characteristic of myriad gene families. These arrangements are found in many evolutionarily divergent fungi and thus represent a widespread, yet underappreciated, layer of transcriptional regulation.
Collapse
|
14
|
Prasad H, Rao R. Histone deacetylase-mediated regulation of endolysosomal pH. J Biol Chem 2018; 293:6721-6735. [PMID: 29567836 DOI: 10.1074/jbc.ra118.002025] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2018] [Revised: 03/19/2018] [Indexed: 11/06/2022] Open
Abstract
The pH of the endolysosomal system is tightly regulated by a balance of proton pump and leak mechanisms that are critical for storage, recycling, turnover, and signaling functions in the cell. Dysregulation of endolysosomal pH has been linked to aging, amyloidogenesis, synaptic dysfunction, and various neurodegenerative disorders, including Alzheimer's disease. Therefore, understanding the mechanisms that regulate luminal pH may be key to identifying new targets for managing these disorders. Meta-analysis of yeast microarray databases revealed that nutrient-limiting conditions inhibited the histone deacetylase (HDAC) Rpd3 and thereby up-regulated transcription of the endosomal Na+/H+ exchanger Nhx1, resulting in vacuolar alkalinization. Consistent with these findings, Rpd3 inhibition by the HDAC inhibitor and antifungal drug trichostatin A induced Nhx1 expression and vacuolar alkalinization. Bioinformatics analysis of Drosophila and mouse databases revealed that caloric control of the Nhx1 orthologs DmNHE3 and NHE6, respectively, is also mediated by HDACs. We show that NHE6 is a target of the transcription factor cAMP-response element-binding protein (CREB), a known regulator of cellular responses to low-nutrient conditions, providing a molecular mechanism for nutrient- and HDAC-dependent regulation of endosomal pH. Of note, pharmacological targeting of the CREB pathway to increase NHE6 expression helped regulate endosomal pH and correct defective clearance of amyloid Aβ in an apoE4 astrocyte model of Alzheimer's disease. These observations from yeast, fly, mouse, and cell culture models point to an evolutionarily conserved mechanism for HDAC-mediated regulation of endosomal NHE expression. Our insights offer new therapeutic strategies for modulation of endolysosomal pH in fungal infection and human disease.
Collapse
Affiliation(s)
- Hari Prasad
- From the Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Rajini Rao
- From the Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| |
Collapse
|
15
|
Abrhámová K, Nemčko F, Libus J, Převorovský M, Hálová M, Půta F, Folk P. Introns provide a platform for intergenic regulatory feedback of RPL22 paralogs in yeast. PLoS One 2018; 13:e0190685. [PMID: 29304067 PMCID: PMC5755908 DOI: 10.1371/journal.pone.0190685] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Accepted: 12/19/2017] [Indexed: 01/04/2023] Open
Abstract
Ribosomal protein genes (RPGs) in Saccharomyces cerevisiae are a remarkable regulatory group that may serve as a model for understanding genetic redundancy in evolutionary adaptations. Most RPGs exist as pairs of highly conserved functional paralogs with divergent untranslated regions and introns. We examined the roles of introns in strains with various combinations of intron and gene deletions in RPL22, RPL2, RPL16, RPL37, RPL17, RPS0, and RPS18 paralog pairs. We found that introns inhibited the expression of their genes in the RPL22 pair, with the RPL22B intron conferring a much stronger effect. While the WT RPL22A/RPL22B mRNA ratio was 93/7, the rpl22aΔi/RPL22B and RPL22A/rpl22bΔi ratios were >99/<1 and 60/40, respectively. The intron in RPL2A stimulated the expression of its own gene, but the removal of the other introns had little effect on expression of the corresponding gene pair. Rpl22 protein abundances corresponded to changes in mRNAs. Using splicing reporters containing endogenous intron sequences, we demonstrated that these effects were due to the inhibition of splicing by Rpl22 proteins but not by their RNA-binding mutant versions. Indeed, only WT Rpl22A/Rpl22B proteins (but not the mutants) interacted in a yeast three-hybrid system with an RPL22B intronic region between bp 165 and 236. Transcriptome analysis showed that both the total level of Rpl22 and the A/B ratio were important for maintaining the WT phenotype. The data presented here support the contention that the Rpl22B protein has a paralog-specific role. The RPL22 singleton of Kluyveromyces lactis, which did not undergo whole genome duplication, also responded to Rpl22-mediated inhibition in K. lactis cells. Vice versa, the overproduction of the K. lactis protein reduced the expression of RPL22A/B in S. cerevisiae. The extraribosomal function of of the K. lactis Rpl22 suggests that the loop regulating RPL22 paralogs of S. cerevisiae evolved from autoregulation.
Collapse
Affiliation(s)
- Kateřina Abrhámová
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Filip Nemčko
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jiří Libus
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Martin Převorovský
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Martina Hálová
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - František Půta
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Petr Folk
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
- * E-mail:
| |
Collapse
|
16
|
Shamsuzzaman M, Bommakanti A, Zapinsky A, Rahman N, Pascual C, Lindahl L. Analysis of cell cycle parameters during the transition from unhindered growth to ribosomal and translational stress conditions. PLoS One 2017; 12:e0186494. [PMID: 29028845 PMCID: PMC5640253 DOI: 10.1371/journal.pone.0186494] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 10/01/2017] [Indexed: 02/07/2023] Open
Abstract
Abrogation of ribosome synthesis (ribosomal stress) leads to cell cycle arrest. However, the immediate cell response to cessation of ribosome formation and the transition from normal cell proliferation to cell cycle arrest have not been characterized. Furthermore, there are conflicting conclusions about whether cells are arrested in G2/M or G1, and whether the cause is dismantling ribosomal assembly per se, or the ensuing decreased number of translating ribosomes. To address these questions, we have compared the time kinetics of key cell cycle parameters after inhibiting ribosome formation or function in Saccharomyces cerevisiae. Within one-to-two hours of repressing genes for individual ribosomal proteins or Translation Elongation factor 3, configurations of spindles, spindle pole bodies began changing. Actin began depolarizing within 4 hours. Thus the loss of ribosome formation and function is sensed immediately. After several hours no spindles or mitotic actin rings were visible, but membrane ingression was completed in most cells and Ace2 was localized to daughter cell nuclei demonstrating that the G1 stage was reached. Thus cell division was completed without the help of a contractile actin ring. Moreover, cell wall material held mother and daughter cells together resulting in delayed cell separation, suggesting that expression or function of daughter gluconases and chitinases is inhibited. Moreover, cell development changes in very similar ways in response to inhibition of ribosome formation and function, compatible with the notion that decreased translation capacity contributes to arresting the cell cycle after abrogation of ribosome biogenesis. Potential implications for the mechanisms of diseases caused by mutations in ribosomal genes (ribosomopathies) are discussed.
Collapse
Affiliation(s)
- Md Shamsuzzaman
- Department of Biological Sciences, University of Maryland Baltimore County (UMBC), Baltimore, Maryland, United States of America
| | - Ananth Bommakanti
- Department of Biological Sciences, University of Maryland Baltimore County (UMBC), Baltimore, Maryland, United States of America
| | - Aviva Zapinsky
- Department of Biological Sciences, University of Maryland Baltimore County (UMBC), Baltimore, Maryland, United States of America
| | - Nusrat Rahman
- Department of Biological Sciences, University of Maryland Baltimore County (UMBC), Baltimore, Maryland, United States of America
| | - Clarence Pascual
- Department of Biological Sciences, University of Maryland Baltimore County (UMBC), Baltimore, Maryland, United States of America
| | - Lasse Lindahl
- Department of Biological Sciences, University of Maryland Baltimore County (UMBC), Baltimore, Maryland, United States of America
| |
Collapse
|
17
|
Bosio MC, Fermi B, Spagnoli G, Levati E, Rubbi L, Ferrari R, Pellegrini M, Dieci G. Abf1 and other general regulatory factors control ribosome biogenesis gene expression in budding yeast. Nucleic Acids Res 2017; 45:4493-4506. [PMID: 28158860 PMCID: PMC5416754 DOI: 10.1093/nar/gkx058] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2016] [Accepted: 01/25/2017] [Indexed: 01/21/2023] Open
Abstract
Ribosome biogenesis in Saccharomyces cerevisiae involves a regulon of >200 genes (Ribi genes) coordinately regulated in response to nutrient availability and cellular growth rate. Two cis-acting elements called PAC and RRPE are known to mediate Ribi gene repression in response to nutritional downshift. Here, we show that most Ribi gene promoters also contain binding sites for one or more General Regulatory Factors (GRFs), most frequently Abf1 and Reb1, and that these factors are enriched in vivo at Ribi promoters. Abf1/Reb1/Tbf1 promoter association was required for full Ribi gene expression in rich medium and for its modulation in response to glucose starvation, characterized by a rapid drop followed by slow recovery. Such a response did not entail changes in Abf1 occupancy, but it was paralleled by a quick increase, followed by slow decrease, in Rpd3L histone deacetylase occupancy. Remarkably, Abf1 site disruption also abolished Rpd3L complex recruitment in response to starvation. Extensive mutational analysis of the DBP7 promoter revealed a complex interplay of Tbf1 sites, PAC and RRPE in the transcriptional regulation of this Ribi gene. Our observations point to GRFs as new multifaceted players in Ribi gene regulation both during exponential growth and under repressive conditions.
Collapse
Affiliation(s)
- Maria Cristina Bosio
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 23/A, 43124 Parma, Italy
| | - Beatrice Fermi
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 23/A, 43124 Parma, Italy
| | - Gloria Spagnoli
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 23/A, 43124 Parma, Italy
| | - Elisabetta Levati
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 23/A, 43124 Parma, Italy
| | - Ludmilla Rubbi
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Roberto Ferrari
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Matteo Pellegrini
- Department of Molecular, Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Giorgio Dieci
- Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, Parco Area delle Scienze 23/A, 43124 Parma, Italy
| |
Collapse
|
18
|
Bosio MC, Fermi B, Dieci G. Transcriptional control of yeast ribosome biogenesis: A multifaceted role for general regulatory factors. Transcription 2017; 8:254-260. [PMID: 28448767 DOI: 10.1080/21541264.2017.1317378] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
In Saccharomyces cerevisiae, a group of more than 200 co-regulated genes (Ribi genes) is involved in ribosome biogenesis. This regulon has recently been shown to rely on a small set of transcriptional regulators (mainly Abf1, but also Reb1, Tbf1 and Rap1) previously referred to as general regulatory factors (GRFs) because of their widespread binding and action at many promoters and other specialized genomic regions. Intriguingly, Abf1 binding to Ribi genes is differentially modulated in response to distinct nutrition signaling pathways. Such a dynamic promoter association has the potential to orchestrate both activation and repression of Ribi genes in synergy with neighboring regulatory sites and through the functional interplay of histone acetyltransferases and deacetylases.
Collapse
Affiliation(s)
- Maria Cristina Bosio
- a Department of Chemistry , Life Sciences and Environmental Sustainability, University of Parma , Parma , Italy
| | - Beatrice Fermi
- a Department of Chemistry , Life Sciences and Environmental Sustainability, University of Parma , Parma , Italy
| | - Giorgio Dieci
- a Department of Chemistry , Life Sciences and Environmental Sustainability, University of Parma , Parma , Italy
| |
Collapse
|
19
|
Multiple roles of the general regulatory factor Abf1 in yeast ribosome biogenesis. Curr Genet 2016; 63:65-68. [PMID: 27262581 DOI: 10.1007/s00294-016-0621-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 05/27/2016] [Accepted: 05/28/2016] [Indexed: 10/21/2022]
Abstract
In Saccharomyces cerevisiae, the large majority of the genes coding for cytoplasmic ribosomal proteins (RPs) depend on the general regulatory factor Rap1 for their transcription, but a small cohort of them relies on Abf1 regulatory activity. A recent study showed that unlike Rap1, whose association with RP gene promoters is not affected by environmental changes causing RP gene repression/reactivation, Abf1 association with both RP gene and ribosome biogenesis (Ribi) gene promoters dynamically responds to changes in growth conditions. This observation changes the paradigm of general regulatory factors as relatively static DNA-binding proteins constitutively bound to highly active promoters, and point to Abf1, which binds hundreds of non-RPG promoters within the yeast genome, as a possible key regulatory switch in nutrient- and stress-dependent transcriptional modulation. Moreover, the frequent presence of Abf1 binding sites in the promoters of mitochondrial RP genes evokes the possibility that Abf1 might orchestrate still unexplored levels of co-regulation involving growth-related gene networks in yeast cells.
Collapse
|