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Chang JS, Huypens P, Zhang Y, Black C, Kralli A, Gettys TW. Regulation of NT-PGC-1alpha subcellular localization and function by protein kinase A-dependent modulation of nuclear export by CRM1. J Biol Chem 2010; 285:18039-50. [PMID: 20351112 PMCID: PMC2878565 DOI: 10.1074/jbc.m109.083121] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Revised: 03/01/2010] [Indexed: 11/06/2022] Open
Abstract
Peroxisome proliferator-activated receptor gamma co-activator-1alpha (PGC-1alpha) plays a central role in the regulation of cellular energy metabolism and metabolic adaptation to environmental and nutritional stimuli. We recently described a novel, biologically active splice variant of PGC-1alpha (NT-PGC-1alpha, amino acids 1-270) that retains the ability to interact with and transactivate nuclear hormone receptors through its N-terminal transactivation domain. Whereas PGC-1alpha is an unstable nuclear protein sensitive to ubiquitin-mediated targeting to the proteasome, NT-PGC-1alpha is relatively stable and predominantly cytoplasmic, suggesting that its ability to interact with and activate nuclear receptors and transcription factors is dependent upon regulated access to the nucleus. We provide evidence that NT-PGC-1alpha interacts with the nuclear exportin, CRM1, through a specific leucine-rich domain (nuclear export sequence) that regulates its export to the cytoplasm. The nuclear export of NT-PGC-1alpha is inhibited by protein kinase A-dependent phosphorylation of Ser-194, Ser-241, and Thr-256 on NT-PGC-1alpha, which effectively increases its nuclear concentration. Using site-directed mutagenesis to prevent or mimic phosphorylation at these sites, we show that the transcriptional activity of NT-PGC-1alpha is regulated in part through regulation of its subcellular localization. These findings suggest that the function of NT-PGC-1alpha as a transcriptional co-activator is regulated by protein kinase A-dependent inhibition of CRM1-mediated export from the nucleus.
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Affiliation(s)
- Ji Suk Chang
- From the Laboratory of Nutrient Sensing and Adipocyte Signaling, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808
| | - Peter Huypens
- From the Laboratory of Nutrient Sensing and Adipocyte Signaling, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808
| | - Yubin Zhang
- From the Laboratory of Nutrient Sensing and Adipocyte Signaling, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808
- the Department of Biochemistry, China Pharmaceutical University, Nanjing 210009, China
| | - Chelsea Black
- From the Laboratory of Nutrient Sensing and Adipocyte Signaling, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808
| | - Anastasia Kralli
- the Department of Chemical Physiology, Scripps Research Institute, La Jolla, California 92037, and
| | - Thomas W. Gettys
- From the Laboratory of Nutrient Sensing and Adipocyte Signaling, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808
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Abstract
Reactive oxygen species generated by activated neutrophils can cause oxidative stress and tissue damage. S100A8 (A8) and S100A9 (A9), abundant in neutrophil cytoplasm, are exquisitely sensitive to oxidation, which may alter their functions. Murine A8 is a neutrophil chemoattractant, but it suppresses leukocyte transmigration in the microcirculation when S-nitrosylated. Glutathione (GSH) modulates intracellular redox, and S-glutathionylation can protect susceptible proteins from oxidative damage and regulate function. We characterized S-glutathionylation of A9; GSSG and GSNO generated S-glutathionylated A8 (A8-SSG) and A9 (A9-SSG) in vitro, whereas only A9-SSG was detected in cytosol of neutrophils activated with phorbol myristate acetate (PMA) but not with fMLP or opsonized zymosan. S-Glutathionylation exposed more hydrophobic regions in Zn(2+)-bound A9 but did not alter Zn(2+) binding affinity. A9-SSG had reduced capacity to form heterocomplexes with A8, but the arachidonic acid binding capacities of A8/A9 and A8/A9-SSG were similar. A9 and A8/A9 bind endothelial cells; S-glutathionylation reduced binding. We found little effect of A9 or A9-SSG on neutrophil CD11b/CD18 expression or neutrophil adhesion to endothelial cells. However, A9, A9-SSG and A8/A9 promoted neutrophil adhesion to fibronectin but, in the presence of A8, A9-mediated adhesion was abrogated by glutathionylation. S-Glutathionylation of A9 may protect its oxidation to higher oligomers and reduce neutrophil binding to the extracellular matrix. This may regulate the magnitude of neutrophil migration in the extravasculature, and together with the functional changes we reported for S-nitrosylated A8, particular oxidative modifications of these proteins may limit tissue damage in acute inflammation.
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Affiliation(s)
- Su Yin Lim
- From the Centre for Infection and Inflammation Research and
| | - Mark J. Raftery
- Bioanalytical Mass Spectrometry Facility, School of Medical Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Jesse Goyette
- From the Centre for Infection and Inflammation Research and
| | - Carolyn L. Geczy
- From the Centre for Infection and Inflammation Research and
- To whom correspondence should be addressed. Tel.: 612-9385-2777; E-mail:
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Yang Y, Cimen H, Han MJ, Shi T, Deng JH, Koc H, Palacios OM, Montier L, Bai Y, Tong Q, Koc EC. NAD+-dependent deacetylase SIRT3 regulates mitochondrial protein synthesis by deacetylation of the ribosomal protein MRPL10. J Biol Chem 2010; 285:7417-7429. [PMID: 20042612 PMCID: PMC2844190 DOI: 10.1074/jbc.m109.053421] [Citation(s) in RCA: 126] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 12/03/2009] [Indexed: 10/02/2023] Open
Abstract
A member of the sirtuin family of NAD(+)-dependent deacetylases, SIRT3, is located in mammalian mitochondria and is important for regulation of mitochondrial metabolism, cell survival, and longevity. In this study, MRPL10 (mitochondrial ribosomal protein L10) was identified as the major acetylated protein in the mitochondrial ribosome. Ribosome-associated SIRT3 was found to be responsible for deacetylation of MRPL10 in an NAD(+)-dependent manner. We mapped the acetylated Lys residues by tandem mass spectrometry and determined the role of these residues in acetylation of MRPL10 by site-directed mutagenesis. Furthermore, we observed that the increased acetylation of MRPL10 led to an increase in translational activity of mitochondrial ribosomes in Sirt3(-/-) mice. In a similar manner, ectopic expression and knockdown of SIRT3 in C2C12 cells resulted in the suppression and enhancement of mitochondrial protein synthesis, respectively. Our findings constitute the first evidence for the regulation of mitochondrial protein synthesis by the reversible acetylation of the mitochondrial ribosome and characterize MRPL10 as a novel substrate of the NAD(+)-dependent deacetylase, SIRT3.
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Affiliation(s)
- Yongjie Yang
- From the Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030
| | - Huseyin Cimen
- the Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, and
| | - Min-Joon Han
- the Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, and
| | - Tong Shi
- From the Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030
| | - Jian-Hong Deng
- the Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Hasan Koc
- the Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, and
| | - Orsolya M. Palacios
- From the Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030
| | - Laura Montier
- the Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Yidong Bai
- the Department of Cellular and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - Qiang Tong
- From the Children's Nutrition Research Center, Baylor College of Medicine, Houston, Texas 77030
| | - Emine C. Koc
- the Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania 16802, and
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Qian Y, Lee I, Lee WS, Qian M, Kudo M, Canfield WM, Lobel P, Kornfeld S. Functions of the alpha, beta, and gamma subunits of UDP-GlcNAc:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase. J Biol Chem 2010; 285:3360-70. [PMID: 19955174 PMCID: PMC2823453 DOI: 10.1074/jbc.m109.068650] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2009] [Revised: 11/30/2009] [Indexed: 11/06/2022] Open
Abstract
UDP-GlcNAc:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase is an alpha(2)beta(2)gamma(2) hexamer that mediates the first step in the synthesis of the mannose 6-phosphate recognition marker on lysosomal acid hydrolases. Using a multifaceted approach, including analysis of acid hydrolase phosphorylation in mice and fibroblasts lacking the gamma subunit along with kinetic studies of recombinant alpha(2)beta(2)gamma(2) and alpha(2)beta(2) forms of the transferase, we have explored the function of the alpha/beta and gamma subunits. The findings demonstrate that the alpha/beta subunits recognize the protein determinant of acid hydrolases in addition to mediating the catalytic function of the transferase. In mouse brain, the alpha/beta subunits phosphorylate about one-third of the acid hydrolases at close to wild-type levels but require the gamma subunit for optimal phosphorylation of the rest of the acid hydrolases. In addition to enhancing the activity of the alpha/beta subunits toward a subset of the acid hydrolases, the gamma subunit facilitates the addition of the second GlcNAc-P to high mannose oligosaccharides of these substrates. We postulate that the mannose 6-phosphate receptor homology domain of the gamma subunit binds and presents the high mannose glycans of the acceptor to the alpha/beta catalytic site in a favorable manner.
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Affiliation(s)
- Yi Qian
- From the Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Intaek Lee
- From the Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Wang-Sik Lee
- From the Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
| | - Meiqian Qian
- the Center for Advanced Biotechnology and Medicine and Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Piscataway, New Jersey 08851, and
| | - Mariko Kudo
- Genzyme Corporation, Oklahoma City, Oklahoma 73104
| | | | - Peter Lobel
- the Center for Advanced Biotechnology and Medicine and Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Piscataway, New Jersey 08851, and
| | - Stuart Kornfeld
- From the Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110
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Phan J, Li Z, Kasprzak A, Li B, Sebti S, Guida W, Schönbrunn E, Chen J. Structure-based design of high affinity peptides inhibiting the interaction of p53 with MDM2 and MDMX. J Biol Chem 2010; 285:2174-83. [PMID: 19910468 PMCID: PMC2804373 DOI: 10.1074/jbc.m109.073056] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Revised: 10/28/2009] [Indexed: 01/22/2023] Open
Abstract
MDM2 and MDMX function as key regulators of p53 by binding to its N terminus, inhibiting its transcriptional activity, and promoting degradation. MDM2 and MDMX overexpression or hyperactivation directly contributes to the loss of p53 function during the development of nearly 50% of human cancers. Recent studies showed that disrupting p53-MDM2 and p53-MDMX interactions can lead to robust activation of p53 but also revealed a need to develop novel dual specific or MDMX-specific inhibitors. Using phage display we identified a 12-residue peptide (pDI) with inhibitory activity against MDM2 and MDMX. The co-crystal structures of the pDI and a single mutant derivative (pDI6W) liganded with the N-terminal domains of human MDMX and MDM2 served as the basis for the design of 11 distinct pDI-derivative peptides that were tested for inhibitory potential. The best derivative (termed pDIQ) contained four amino acid substitutions and exhibited a 5-fold increase in potency over the parent peptide against both MDM2 (IC(50) = 8 nm) and MDMX (IC(50) = 110 nm). Further structural studies revealed key molecular features enabling the high affinity binding of the pDIQ to these proteins. These include large conformational changes of the pDIQ to reach into a hydrophobic site unique to MDMX. The findings suggest new strategies toward the rational design of small molecule inhibitors efficiently targeting MDMX.
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Affiliation(s)
- Jason Phan
- Drug Discovery Departments, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612 and
| | | | - Agnieszka Kasprzak
- Drug Discovery Departments, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612 and
| | | | - Said Sebti
- Drug Discovery Departments, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612 and
- the Department of Oncologic Sciences, University of South Florida, Tampa, Florida 33612
| | - Wayne Guida
- Drug Discovery Departments, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612 and
- the Department of Oncologic Sciences, University of South Florida, Tampa, Florida 33612
| | - Ernst Schönbrunn
- Drug Discovery Departments, H. Lee Moffitt Cancer Center and Research Institute, Tampa, Florida 33612 and
- the Department of Oncologic Sciences, University of South Florida, Tampa, Florida 33612
| | - Jiandong Chen
- From the Molecular Oncology and
- the Department of Oncologic Sciences, University of South Florida, Tampa, Florida 33612
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