1
|
Boltengagen M, Samel-Pommerencke A, Fechtig D, Ehrenhofer-Murray AE. Dynamics of SAS-I mediated H4 K16 acetylation during DNA replication in yeast. PLoS One 2021; 16:e0251660. [PMID: 34014972 PMCID: PMC8136709 DOI: 10.1371/journal.pone.0251660] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Accepted: 04/29/2021] [Indexed: 11/19/2022] Open
Abstract
The acetylation of H4 lysine 16 (H4 K16Ac) in Saccharomyces cerevisiae counteracts the binding of the heterochromatin complex SIR to chromatin and inhibits gene silencing. Contrary to other histone acetylation marks, the H4 K16Ac level is high on genes with low transcription, whereas highly transcribed genes show low H4 K16Ac. Approximately 60% of cellular H4 K16Ac in S. cerevisiae is provided by the SAS-I complex, which consists of the MYST-family acetyltransferase Sas2, Sas4 and Sas5. The absence of SAS-I causes inappropriate spreading of the SIR complex and gene silencing in subtelomeric regions. Here, we investigated the genome-wide dynamics of SAS-I dependent H4 K16Ac during DNA replication. Replication is highly disruptive to chromatin and histone marks, since histones are removed to allow progression of the replication fork, and chromatin is reformed with old and new histones after fork passage. We found that H4 K16Ac appears in chromatin immediately upon replication. Importantly, this increase depends on the presence of functional SAS-I complex. Moreover, the appearance of H4 K16Ac is delayed in genes that are strongly transcribed. This indicates that transcription counteracts SAS-I-mediated H4 K16 acetylation, thus “sculpting” histone modification marks at the time of replication. We furthermore investigated which acetyltransferase acts redundantly with SAS-I to acetylate H4 K16Ac. esa1Δ sds3Δ cells, which were also sas2Δ sir3Δ in order to maintain viability, contained no detectable H4 K16Ac, showing that Esa1 and Sas2 are redundant for cellular H4 K16 acetylation. Furthermore, esa1Δ sds3Δ sas2Δ sir3Δ showed a more pronounced growth defect compared to the already defective esa1Δ sds3Δ sir3Δ. This indicates that SAS-I has cellular functions beyond preventing the spreading of heterochromatin.
Collapse
Affiliation(s)
- Mark Boltengagen
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | | | - David Fechtig
- Institut für Biologie, Humboldt-Universität zu Berlin, Berlin, Germany
| | | |
Collapse
|
2
|
Espinosa-Cantú A, Cruz-Bonilla E, Noda-Garcia L, DeLuna A. Multiple Forms of Multifunctional Proteins in Health and Disease. Front Cell Dev Biol 2020; 8:451. [PMID: 32587857 PMCID: PMC7297953 DOI: 10.3389/fcell.2020.00451] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Accepted: 05/14/2020] [Indexed: 12/23/2022] Open
Abstract
Protein science has moved from a focus on individual molecules to an integrated perspective in which proteins emerge as dynamic players with multiple functions, rather than monofunctional specialists. Annotation of the full functional repertoire of proteins has impacted the fields of biochemistry and genetics, and will continue to influence basic and applied science questions - from the genotype-to-phenotype problem, to our understanding of human pathologies and drug design. In this review, we address the phenomena of pleiotropy, multidomain proteins, promiscuity, and protein moonlighting, providing examples of multitasking biomolecules that underlie specific mechanisms of human disease. In doing so, we place in context different types of multifunctional proteins, highlighting useful attributes for their systematic definition and classification in future research directions.
Collapse
Affiliation(s)
- Adriana Espinosa-Cantú
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados, Guanajuato, Mexico
| | - Erika Cruz-Bonilla
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados, Guanajuato, Mexico
| | - Lianet Noda-Garcia
- Department of Plant Pathology and Microbiology, Robert H. Smith Faculty of Agriculture, Food, and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Alexander DeLuna
- Unidad de Genómica Avanzada (Langebio), Centro de Investigación y de Estudios Avanzados, Guanajuato, Mexico
| |
Collapse
|
3
|
Farley-Barnes KI, McCann KL, Ogawa LM, Merkel J, Surovtseva YV, Baserga SJ. Diverse Regulators of Human Ribosome Biogenesis Discovered by Changes in Nucleolar Number. Cell Rep 2019; 22:1923-1934. [PMID: 29444442 PMCID: PMC5828527 DOI: 10.1016/j.celrep.2018.01.056] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 11/09/2017] [Accepted: 11/19/2017] [Indexed: 12/31/2022] Open
Abstract
Ribosome biogenesis is a highly regulated, essential cellular process. Although studies in yeast have established some of the biological principles of ribosome biogenesis, many of the intricacies of its regulation in higher eukaryotes remain unknown. To understand how ribosome biogenesis is globally integrated in human cells, we conducted a genome-wide siRNA screen for regulators of nucleolar number. We found 139 proteins whose depletion changed the number of nucleoli per nucleus from 2–3 to only 1 in human MCF10A cells. Follow-up analyses on 20 hits found many (90%) to be essential for the nucleolar functions of rDNA transcription (7), pre-ribosomal RNA (pre-rRNA) processing (16), and/or global protein synthesis (14). This genome-wide analysis exploits the relationship between nucleolar number and function to discover diverse cellular pathways that regulate the making of ribosomes and paves the way for further exploration of the links between ribosome biogenesis and human disease.
Collapse
Affiliation(s)
- Katherine I Farley-Barnes
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Kathleen L McCann
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA; Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, NIH, PO Box 12233 MD F3-05, Research Triangle Park, NC 27709, USA
| | - Lisa M Ogawa
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Janie Merkel
- Yale Center for Molecular Discovery, Yale University, 600 West Campus Drive, West Haven, CT 06516, USA
| | - Yulia V Surovtseva
- Yale Center for Molecular Discovery, Yale University, 600 West Campus Drive, West Haven, CT 06516, USA
| | - Susan J Baserga
- Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Genetics, Yale University School of Medicine, New Haven, CT 06520, USA; Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, CT 06520, USA.
| |
Collapse
|
4
|
Marquez-Lona EM, Torres-Machorro AL, Gonzales FR, Pillus L, Patrick GN. Phosphorylation of the 19S regulatory particle ATPase subunit, Rpt6, modifies susceptibility to proteotoxic stress and protein aggregation. PLoS One 2017; 12:e0179893. [PMID: 28662109 PMCID: PMC5491056 DOI: 10.1371/journal.pone.0179893] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 06/06/2017] [Indexed: 12/22/2022] Open
Abstract
The ubiquitin proteasome system (UPS) is a highly conserved and tightly regulated biochemical pathway that degrades the majority of proteins in eukaryotic cells. Importantly, the UPS is responsible for counteracting altered protein homeostasis induced by a variety of proteotoxic stresses. We previously reported that Rpt6, the ATPase subunit of the 19S regulatory particle (RP) of the 26S proteasome, is phosphorylated in mammalian neurons at serine 120 in response to neuronal activity. Furthermore, we found that Rpt6 S120 phosphorylation, which regulates the activity and distribution of proteasomes in neurons, is relevant for proteasome-dependent synaptic remodeling and function. To better understand the role of proteasome phosphorylation, we have constructed models of altered Rpt6 phosphorylation in S. cerevisiae by introducing chromosomal point mutations that prevent or mimic phosphorylation at the conserved serine (S119). We find that mutants which prevent Rpt6 phosphorylation at this site (rpt6-S119A), had increased susceptibility to proteotoxic stress, displayed abnormal morphology and had reduced proteasome activity. Since impaired proteasome function has been linked to the aggregation of toxic proteins including the Huntington’s disease (HD) related huntingtin (Htt) protein with expanded polyglutamine repeats, we evaluated the extent of Htt aggregation in our phospho-dead (rpt6-S119A) and phospho-mimetic (rpt6-S119D) mutants. We showed Htt103Q aggregate size to be significantly larger in rpt6-S119A mutants compared to wild-type or rpt6-S119D strains. Furthermore, we observed that phosphorylation of endogenous Rpt6 at S119 is increased in response to various stress conditions. Together, these data suggest that Rpt6 phosphorylation at S119 may play an important function in proteasome-dependent relief of proteotoxic stress that can be critical in protein aggregation pathologies.
Collapse
Affiliation(s)
- Esther Magdalena Marquez-Lona
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Ana Lilia Torres-Machorro
- Section of Molecular Biology and UCSD Moores Cancer Center, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Frankie R. Gonzales
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Lorraine Pillus
- Section of Molecular Biology and UCSD Moores Cancer Center, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
| | - Gentry N. Patrick
- Section of Neurobiology, Division of Biological Sciences, University of California San Diego, La Jolla, California, United States of America
- * E-mail:
| |
Collapse
|
5
|
Chromatin Regulation by the NuA4 Acetyltransferase Complex Is Mediated by Essential Interactions Between Enhancer of Polycomb (Epl1) and Esa1. Genetics 2017; 205:1125-1137. [PMID: 28108589 DOI: 10.1534/genetics.116.197830] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 01/16/2017] [Indexed: 12/20/2022] Open
Abstract
Enzymes that modify and remodel chromatin act in broadly conserved macromolecular complexes. One key modification is the dynamic acetylation of histones and other chromatin proteins by opposing activities of acetyltransferase and deacetylase complexes. Among acetyltransferases, the NuA4 complex containing Tip60 or its Saccharomyces cerevisiae ortholog Esa1 is of particular significance because of its roles in crucial genomic processes including DNA damage repair and transcription. The catalytic subunit Esa1 is essential, as are five noncatalytic NuA4 subunits. We found that of the noncatalytic subunits, deletion of Enhancer of polycomb (Epl1), but not the others, can be bypassed by loss of a major deacetylase complex, a property shared by Esa1 Noncatalytic complex subunits can be critical for complex assembly, stability, genomic targeting, substrate specificity, and regulation. Understanding the essential role of Epl1 has been previously limited, a limitation now overcome by the discovery of its bypass suppression. Here, we present a comprehensive in vivo study of Epl1 using the powerful tool of suppression combined with transcriptional and mutational analyses. Our results highlight functional parallels between Epl1 and Esa1 and further illustrate that the structural role of Epl1 is important for promotion of Esa1 activity. This conclusion is strengthened by our dissection of Epl1 domains required in vivo for interaction with specific NuA4 subunits, histone acetylation, and chromatin targeting. These results provide new insights for the conserved, essential nature of Epl1 and its homologs, such as EPC1/2 in humans, which is frequently altered in cancers.
Collapse
|
6
|
The Set3 Complex Antagonizes the MYST Acetyltransferase Esa1 in the DNA Damage Response. Mol Cell Biol 2015; 35:3714-25. [PMID: 26303527 DOI: 10.1128/mcb.00298-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2015] [Accepted: 08/14/2015] [Indexed: 11/20/2022] Open
Abstract
Acetylation is a dynamic posttranslational modification that contributes to chromatin-regulated processes, including DNA replication, repair, recombination, and gene expression. Acetylation is controlled by complexes containing opposing lysine and histone acetyltransferase (KAT and HAT) and deacetylase (KDAC and HDAC) activities. The essential MYST family Esa1 KAT acetylates core histones and many nonhistone substrates. Phenotypes of esa1 mutants include transcriptional silencing and activation defects, impaired growth at high temperatures, and sensitivity to DNA damage. The KDAC Rpd3 was previously identified as an activity opposing Esa1, as its deletion suppresses growth and silencing defects of esa1 mutants. However, loss of Rpd3 does not suppress esa1 DNA damage sensitivity. In this work, we identified Hos2 as a KDAC counteracting ESA1 in the damage response. Deletion of HOS2 resulted in changes of esa1's transcriptional response upon damage. Further, loss of HOS2 or components of the Set3 complex (Set3C) in which it acts specifically suppressed damage sensitivity and restored esa1 histone H4 acetylation. This rescue was mediated via loss of either Set3C integrity or of its binding to dimethylated histone H3K4. Our results thus add new insight into the interactions of an essential MYST acetyltransferase with diverse deacetylases to respond specifically to environmental and physiological challenges.
Collapse
|
7
|
Torres-Machorro AL, Aris JP, Pillus L. A moonlighting metabolic protein influences repair at DNA double-stranded breaks. Nucleic Acids Res 2015; 43:1646-58. [PMID: 25628362 PMCID: PMC4330366 DOI: 10.1093/nar/gku1405] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Catalytically active proteins with divergent dual functions are often described as ‘moonlighting’. In this work we characterize a new, chromatin-based function of Lys20, a moonlighting protein that is well known for its role in metabolism. Lys20 was initially described as homocitrate synthase (HCS), the first enzyme in the lysine biosynthetic pathway in yeast. Its nuclear localization led to the discovery of a key role for Lys20 in DNA damage repair through its interaction with the MYST family histone acetyltransferase Esa1. Overexpression of Lys20 promotes suppression of DNA damage sensitivity of esa1 mutants. In this work, by taking advantage of LYS20 mutants that are active in repair but not in lysine biosynthesis, the mechanism of suppression of esa1 was characterized. First we analyzed the chromatin landscape of esa1 cells, finding impaired histone acetylation and eviction. Lys20 was recruited to sites of DNA damage, and its overexpression promoted enhanced recruitment of the INO80 remodeling complex to restore normal histone eviction at the damage sites. This study improves understanding of the evolutionary, structural and biological relevance of independent activities in a moonlighting protein and links metabolism to DNA damage repair.
Collapse
Affiliation(s)
- Ana Lilia Torres-Machorro
- Section of Molecular Biology, Division of Biological Sciences, UC San Diego Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093-0347, USA
| | - John P Aris
- Department of Anatomy and Cell Biology, Health Science Center, University of Florida, Gainesville, FL 32610-0235, USA
| | - Lorraine Pillus
- Section of Molecular Biology, Division of Biological Sciences, UC San Diego Moores Cancer Center, University of California, San Diego, La Jolla, CA 92093-0347, USA
| |
Collapse
|
8
|
Abstract
Histone acetylation is a key regulatory feature for chromatin that is established by opposing enzymatic activities of lysine acetyltransferases (KATs/HATs) and deacetylases (KDACs/HDACs). Esa1, like its human homolog Tip60, is an essential MYST family enzyme that acetylates histones H4 and H2A and other nonhistone substrates. Here we report that the essential requirement for ESA1 in Saccharomyces cerevisiae can be bypassed upon loss of Sds3, a noncatalytic subunit of the Rpd3L deacetylase complex. By studying the esa1∆ sds3∆ strain, we conclude that the essential function of Esa1 is in promoting the cellular balance of acetylation. We demonstrate this by fine-tuning acetylation through modulation of HDACs and the histone tails themselves. Functional interactions between Esa1 and HDACs of class I, class II, and the Sirtuin family define specific roles of these opposing activities in cellular viability, fitness, and response to stress. The fact that both increased and decreased expression of the ESA1 homolog TIP60 has cancer associations in humans underscores just how important the balance of its activity is likely to be for human well-being.
Collapse
|