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Differential requirements for different subfamilies of the mammalian SWI/SNF chromatin remodeling enzymes in myoblast cell cycle progression and expression of the Pax7 regulator. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2022; 1865:194801. [PMID: 35217218 PMCID: PMC8948540 DOI: 10.1016/j.bbagrm.2022.194801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 01/29/2022] [Accepted: 02/14/2022] [Indexed: 11/21/2022]
Abstract
The mammalian SWItch/Sucrose Non-Fermentable (mSWI/SNF) families of ATP-dependent chromatin remodeling enzymes are established co-regulators of gene expression. mSWI/SNF complexes can be assembled into three major subfamilies: BAF (BRG1 or BRM-Associated Factor), PBAF (Polybromo containing BAF), or ncBAF (non-canonical BAF) that are distinguished by the presence of mutually exclusive subunits. The mechanisms by which each subfamily contributes to the establishment or function of specific cell lineages are poorly understood. Here, we determined the contributions of the BAF, ncBAF, and PBAF complexes to myoblast proliferation via knock down (KD) of distinguishing subunits from each complex. KD of subunits unique to the BAF or the ncBAF complexes reduced myoblast proliferation rate, while KD of PBAF-specific subunits did not affect proliferation. RNA-seq from proliferating KD myoblasts targeting Baf250A (BAF complex), Brd9 (ncBAF complex), or Baf180 (PBAF complex) showed mis-regulation of a limited number of genes. KD of Baf250A specifically reduced the expression of Pax7, which is required for myoblast proliferation, concomitant with decreased binding of Baf250A to and impaired chromatin remodeling at the Pax7 gene promoter. Although Brd9 also bound to the Pax7 promoter, suggesting occupancy by the ncBAF complex, no changes were detected in Pax7 gene expression, Pax7 protein expression or chromatin remodeling at the Pax7 promoter upon Brd9 KD. The data indicate that the BAF subfamily of the mSWI/SNF enzymes is specifically required for myoblast proliferation via regulation of Pax7 expression.
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Chandradoss KR, Guthikonda PK, Kethavath S, Dass M, Singh H, Nayak R, Kurukuti S, Sandhu KS. Biased visibility in Hi-C datasets marks dynamically regulated condensed and decondensed chromatin states genome-wide. BMC Genomics 2020; 21:175. [PMID: 32087673 PMCID: PMC7036197 DOI: 10.1186/s12864-020-6580-6] [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: 09/10/2019] [Accepted: 02/13/2020] [Indexed: 01/29/2023] Open
Abstract
Background Proximity ligation based techniques, like Hi-C, involve restriction digestion followed by ligation of formaldehyde cross-linked chromatin. Distinct chromatin states can impact the restriction digestion, and hence the visibility in the contact maps, of engaged loci. Yet, the extent and the potential impact of digestion bias remain obscure and under-appreciated in the literature. Results Through analysis of 45 Hi-C datasets, lamina-associated domains (LADs), inactive X-chromosome in mammals, and polytene bands in fly, we first established that the DNA in condensed chromatin had lesser accessibility to restriction endonucleases used in Hi-C as compared to that in decondensed chromatin. The observed bias was independent of known systematic biases, was not appropriately corrected by existing computational methods, and needed an additional optimization step. We then repurposed this bias to identify novel condensed domains outside LADs, which were bordered by insulators and were dynamically associated with the polycomb mediated epigenetic and transcriptional states during development. Conclusions Our observations suggest that the corrected one-dimensional read counts of existing Hi-C datasets can be reliably repurposed to study the gene-regulatory dynamics associated with chromatin condensation and decondensation, and that the existing Hi-C datasets should be interpreted with cautions.
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Affiliation(s)
- Keerthivasan Raanin Chandradoss
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) - Mohali, Knowledge City, Sector 81, SAS Nagar, 140306, India
| | - Prashanth Kumar Guthikonda
- Department of Animal Biology, School of Life Sciences, University of Hyderabad (UoH), Central University, Prof. CN Rao Road, P O, Gachibowli, Hyderabad, Telangana, 500046, India
| | - Srinivas Kethavath
- Department of Animal Biology, School of Life Sciences, University of Hyderabad (UoH), Central University, Prof. CN Rao Road, P O, Gachibowli, Hyderabad, Telangana, 500046, India
| | - Monika Dass
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) - Mohali, Knowledge City, Sector 81, SAS Nagar, 140306, India
| | - Harpreet Singh
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) - Mohali, Knowledge City, Sector 81, SAS Nagar, 140306, India
| | - Rakhee Nayak
- Department of Animal Biology, School of Life Sciences, University of Hyderabad (UoH), Central University, Prof. CN Rao Road, P O, Gachibowli, Hyderabad, Telangana, 500046, India
| | - Sreenivasulu Kurukuti
- Department of Animal Biology, School of Life Sciences, University of Hyderabad (UoH), Central University, Prof. CN Rao Road, P O, Gachibowli, Hyderabad, Telangana, 500046, India.
| | - Kuljeet Singh Sandhu
- Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) - Mohali, Knowledge City, Sector 81, SAS Nagar, 140306, India.
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MyoD Regulates Skeletal Muscle Oxidative Metabolism Cooperatively with Alternative NF-κB. Cell Rep 2017; 17:514-526. [PMID: 27705798 DOI: 10.1016/j.celrep.2016.09.010] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 08/08/2016] [Accepted: 09/02/2016] [Indexed: 01/25/2023] Open
Abstract
MyoD is a key regulator of skeletal myogenesis that directs contractile protein synthesis, but whether this transcription factor also regulates skeletal muscle metabolism has not been explored. In a genome-wide ChIP-seq analysis of skeletal muscle cells, we unexpectedly observed that MyoD directly binds to numerous metabolic genes, including those associated with mitochondrial biogenesis, fatty acid oxidation, and the electron transport chain. Results in cultured cells and adult skeletal muscle confirmed that MyoD regulates oxidative metabolism through multiple transcriptional targets, including PGC-1β, a master regulator of mitochondrial biogenesis. We find that PGC-1β expression is cooperatively regulated by MyoD and the alternative NF-κB signaling pathway. Bioinformatics evidence suggests that this cooperativity between MyoD and NF-κB extends to other metabolic genes as well. Together, these data identify MyoD as a regulator of the metabolic capacity of mature skeletal muscle to ensure that sufficient energy is available to support muscle contraction.
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Padilla-Benavides T, Nasipak BT, Paskavitz AL, Haokip DT, Schnabl JM, Nickerson JA, Imbalzano AN. Casein kinase 2-mediated phosphorylation of Brahma-related gene 1 controls myoblast proliferation and contributes to SWI/SNF complex composition. J Biol Chem 2017; 292:18592-18607. [PMID: 28939766 PMCID: PMC5682968 DOI: 10.1074/jbc.m117.799676] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 09/06/2017] [Indexed: 01/01/2023] Open
Abstract
Transcriptional regulation is modulated in part by chromatin-remodeling enzymes that control gene accessibility by altering chromatin compaction or nucleosome positioning. Brahma-related gene 1 (Brg1), a catalytic subunit of the mammalian SWI/SNF chromatin-remodeling enzymes, is required for both myoblast proliferation and differentiation, and the control of Brg1 phosphorylation by calcineurin, PKCβ1, and p38 regulates the transition to differentiation. However, we hypothesized that Brg1 activity might be regulated by additional kinases. Here, we report that Brg1 is also a target of casein kinase 2 (CK2), a serine/threonine kinase, in proliferating myoblasts. We found that CK2 interacts with Brg1, and mutation of putative phosphorylation sites to non-phosphorylatable (Ser to Ala, SA) or phosphomimetic residues (Ser to Glu, SE) reduced Brg1 phosphorylation by CK2. Although BRG1-deleted myoblasts that ectopically express the SA-Brg1 mutant proliferated similarly to the parental cells or cells ectopically expressing wild-type (WT) Brg1, ectopic expression of the SE-Brg1 mutant reduced proliferation and increased cell death, similar to observations from cells lacking Brg1. Moreover, pharmacological inhibition of CK2 increased myoblast proliferation. Furthermore, the Pax7 promoter, which controls expression of a key transcription factor required for myoblast proliferation, was in an inaccessible chromatin state in the SE-Brg1 mutant, suggesting that hyperphosphorylated Brg1 cannot remodel chromatin. WT-, SA-, and SE-Brg1 exhibited distinct differences in interacting with and affecting expression of the SWI/SNF subunits Baf155 and Baf170 and displayed differential sub-nuclear localization. Our results indicate that CK2-mediated phosphorylation of Brg1 regulates myoblast proliferation and provides insight into one mechanism by which composition of the mammalian SWI/SNF enzyme complex is regulated.
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Affiliation(s)
- Teresita Padilla-Benavides
- From the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605 and
| | - Brian T Nasipak
- From the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605 and
| | - Amanda L Paskavitz
- From the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605 and
| | - Dominic T Haokip
- From the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605 and
| | - Jake M Schnabl
- From the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605 and
| | - Jeffrey A Nickerson
- the Department of Pediatrics, University of Massachusetts Medical School, Worcester, Massachusetts 01655
| | - Anthony N Imbalzano
- From the Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605 and
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Nguyen TT, Savory JGA, Brooke-Bisschop T, Ringuette R, Foley T, Hess BL, Mulatz KJ, Trinkle-Mulcahy L, Lohnes D. Cdx2 Regulates Gene Expression through Recruitment of Brg1-associated Switch-Sucrose Non-fermentable (SWI-SNF) Chromatin Remodeling Activity. J Biol Chem 2017; 292:3389-3399. [PMID: 28082674 DOI: 10.1074/jbc.m116.752774] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Revised: 01/10/2017] [Indexed: 12/22/2022] Open
Abstract
The packaging of genomic DNA into nucleosomes creates a barrier to transcription that can be relieved through ATP-dependent chromatin remodeling via complexes such as the switch-sucrose non-fermentable (SWI-SNF) chromatin remodeling complex. The SWI-SNF complex remodels chromatin via conformational or positional changes of nucleosomes, thereby altering the access of transcriptional machinery to target genes. The SWI-SNF complex has limited ability to bind to sequence-specific elements, and, therefore, its recruitment to target loci is believed to require interaction with DNA-associated transcription factors. The Cdx family of homeodomain transcript ion factors (Cdx1, Cdx2, and Cdx4) are essential for a number of developmental programs in the mouse. Cdx1 and Cdx2 also regulate intestinal homeostasis throughout life. Although a number of Cdx target genes have been identified, the basis by which Cdx members impact their transcription is poorly understood. We have found that Cdx members interact with the SWI-SNF complex and make direct contact with Brg1, a catalytic member of SWI-SNF. Both Cdx2 and Brg1 co-occupy a number of Cdx target genes, and both factors are necessary for transcriptional regulation of such targets. Finally, Cdx2 and Brg1 occupancy occurs coincident with chromatin remodeling at some of these loci. Taken together, our findings suggest that Cdx transcription factors regulate target gene expression, in part, through recruitment of Brg1-associated SWI-SNF chromatin remodeling activity.
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Affiliation(s)
- Thinh T Nguyen
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Joanne G A Savory
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Travis Brooke-Bisschop
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Randy Ringuette
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Tanya Foley
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Bradley L Hess
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Kirk J Mulatz
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - Laura Trinkle-Mulcahy
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada
| | - David Lohnes
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H 8M5, Canada.
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Hu G, Gong AY, Wang Y, Ma S, Chen X, Chen J, Su CJ, Shibata A, Strauss-Soukup JK, Drescher KM, Chen XM. LincRNA-Cox2 Promotes Late Inflammatory Gene Transcription in Macrophages through Modulating SWI/SNF-Mediated Chromatin Remodeling. THE JOURNAL OF IMMUNOLOGY 2016; 196:2799-2808. [PMID: 26880762 DOI: 10.4049/jimmunol.1502146] [Citation(s) in RCA: 150] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 01/07/2016] [Indexed: 11/19/2022]
Abstract
Long intergenic noncoding RNAs (lincRNAs) are long noncoding transcripts (>200 nt) from the intergenic regions of annotated protein-coding genes. One of the most highly induced lincRNAs in macrophages upon TLR ligation is lincRNA-Cox2, which was recently shown to mediate the activation and repression of distinct classes of immune genes in innate immune cells. We report that lincRNA-Cox2, located at chromosome 1 proximal to the PG-endoperoxide synthase 2 (Ptgs2/Cox2) gene, is an early-primary inflammatory gene controlled by NF-κB signaling in murine macrophages. Functionally, lincRNA-Cox2 is required for the transcription of NF-κB-regulated late-primary inflammatory response genes stimulated by bacterial LPS. Specifically, lincRNA-Cox2 is assembled into the switch/sucrose nonfermentable (SWI/SNF) complex in cells after LPS stimulation. This resulting lincRNA-Cox2/SWI/SNF complex can modulate the assembly of NF-κB subunits to the SWI/SNF complex, and ultimately, SWI/SNF-associated chromatin remodeling and transactivation of the late-primary inflammatory-response genes in macrophages in response to microbial challenge. Therefore, our data indicate a new regulatory role for NF-κB-induced lincRNA-Cox2 as a coactivator of NF-κB for the transcription of late-primary response genes in innate immune cells through modulation of epigenetic chromatin remodeling.
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Affiliation(s)
- Guoku Hu
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, NE 68178, USA.,School of Medicine, University of Electronic Science and Technology of China, Chengdu, 610054, China
| | - Ai-Yu Gong
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Yang Wang
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Shibin Ma
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Xiqiang Chen
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Jing Chen
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Chun-Jen Su
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Annemarie Shibata
- Department of Biology, Creighton University College of Arts and Sciences, Omaha, NE 68178, USA
| | - Juliane K Strauss-Soukup
- Department of Chemistry, Creighton University College of Arts and Sciences, Omaha, NE 68178, USA
| | - Kristen M Drescher
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, NE 68178, USA
| | - Xian-Ming Chen
- Department of Medical Microbiology and Immunology, Creighton University School of Medicine, Omaha, NE 68178, USA
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Padilla-Benavides T, Nasipak BT, Imbalzano AN. Brg1 Controls the Expression of Pax7 to Promote Viability and Proliferation of Mouse Primary Myoblasts. J Cell Physiol 2015; 230:2990-7. [PMID: 26036967 DOI: 10.1002/jcp.25031] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 05/04/2015] [Indexed: 12/29/2022]
Abstract
Brg1 (Brahma-related gene 1) is a catalytic component of the evolutionarily conserved mammalian SWI/SNF ATP-dependent chromatin remodeling enzymes that disrupt histone-DNA contacts on the nucleosome. While the requirement for the SWI/SNF enzymes in cell differentiation has been extensively studied, its role in precursor cell proliferation and survival is not as well defined. Muscle satellite cells constitute the stem cell pool that sustains and regenerates myofibers in adult skeletal muscle. Here, we show that deletion of Brg1 in primary mouse myoblasts derived from muscle satellite cells cultured ex vivo leads to a cell proliferation defect and apoptosis. We determined that Brg1 regulates cell proliferation and survival by controlling chromatin remodeling and activating transcription at the Pax7 promoter, which is expressed during somite development and is required for controlling viability of the satellite cell population. Reintroduction of catalytically active Brg1 or of Pax7 into Brg1-deficient satellite cells rescued the apoptotic phenotype and restored proliferation. These data demonstrate that Brg1 functions as a positive regulator for cellular proliferation and survival of primary myoblasts. Therefore, the regulation of gene expression through Brg1-mediated chromatin remodeling is critical not just for skeletal muscle differentiation but for maintaining the myoblast population as well.
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Affiliation(s)
- Teresita Padilla-Benavides
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Brian T Nasipak
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts
| | - Anthony N Imbalzano
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts
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Nasipak BT, Padilla-Benavides T, Green KM, Leszyk JD, Mao W, Konda S, Sif S, Shaffer SA, Ohkawa Y, Imbalzano AN. Opposing calcium-dependent signalling pathways control skeletal muscle differentiation by regulating a chromatin remodelling enzyme. Nat Commun 2015; 6:7441. [PMID: 26081415 PMCID: PMC4530624 DOI: 10.1038/ncomms8441] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 05/06/2015] [Indexed: 01/03/2023] Open
Abstract
Calcium signaling is important for differentiation-dependent gene expression, but is also involved in other cellular functions. Therefore mechanisms must exist to distinguish calcium signaling relevant to differentiation. Calcineurin is a calcium-regulated phosphatase that is required for myogenic gene expression and skeletal muscle differentiation. Here, we demonstrate that inhibition of calcineurin blocks chromatin remodeling and that the Brg1 ATPase of the SWI/SNF chromatin remodeling enzyme, which is required for the activation of myogenic gene expression, is a calcineurin substrate. Furthermore, we identify the calcium-regulated classical protein kinase C beta (PKCβ) as a repressor of myogenesis and as the enzyme that opposes calcineurin function. Replacement of endogenous Brg1 with a phosphomimetic mutant in primary myoblasts inhibits myogenesis, while replacement with a non-phosphorylatable mutant allows myogenesis despite inhibition of calcineurin signaling, demonstrating the functionality of calcineurin/PKC modified residues. Thus the Brg1 chromatin remodeling enzyme integrates two antagonistic calcium-dependent signaling pathways that control myogenic differentiation.
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Affiliation(s)
- Brian T Nasipak
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Teresita Padilla-Benavides
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Karin M Green
- Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - John D Leszyk
- Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Wenjie Mao
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Silvana Konda
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Saïd Sif
- Department of Internal Medicine, College of Medicine, Ohio State University, Columbus, Ohio 43210, USA.,Department of Biological and Environmental Sciences, College of Arts and Sciences, Qatar University, PO Box 2713, Doha, Qatar
| | - Scott A Shaffer
- Proteomics and Mass Spectrometry Facility, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
| | - Yasuyuki Ohkawa
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA.,Department Advanced Medical Initiatives, JST-CREST, Faculty of Medicine, Kyushu University, 3-1-1 Maidashi Fukuoka 812-8582, Japan
| | - Anthony N Imbalzano
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, 55 Lake Avenue North, Worcester, Massachusetts 01655, USA
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