1
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Ceron RH, Báez-Cruz FA, Palmer NJ, Carman PJ, Boczkowska M, Heuckeroth RO, Ostap EM, Dominguez R. Molecular mechanisms linking missense ACTG2 mutations to visceral myopathy. SCIENCE ADVANCES 2024; 10:eadn6615. [PMID: 38820162 PMCID: PMC11141634 DOI: 10.1126/sciadv.adn6615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 04/29/2024] [Indexed: 06/02/2024]
Abstract
Visceral myopathy is a life-threatening disease characterized by muscle weakness in the bowel, bladder, and uterus. Mutations in smooth muscle γ-actin (ACTG2) are the most common cause of the disease, but the mechanisms by which the mutations alter muscle function are unknown. Here, we examined four prevalent ACTG2 mutations (R40C, R148C, R178C, and R257C) that cause different disease severity and are spread throughout the actin fold. R178C displayed premature degradation, R148C disrupted interactions with actin-binding proteins, R40C inhibited polymerization, and R257C destabilized filaments. Because these mutations are heterozygous, we also analyzed 50/50 mixtures with wild-type (WT) ACTG2. The WT/R40C mixture impaired filament nucleation by leiomodin 1, and WT/R257C produced filaments that were easily fragmented by smooth muscle myosin. Smooth muscle tropomyosin isoform Tpm1.4 partially rescued the defects of R40C and R257C. Cryo-electron microscopy structures of filaments formed by R40C and R257C revealed disrupted intersubunit contacts. The biochemical and structural properties of the mutants correlate with their genotype-specific disease severity.
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Affiliation(s)
- Rachel H. Ceron
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- The Children’s Hospital of Philadelphia Research Institute, Philadelphia, PA 19104, USA
| | - Faviolla A. Báez-Cruz
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Nicholas J. Palmer
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Peter J. Carman
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Malgorzata Boczkowska
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Robert O. Heuckeroth
- The Children’s Hospital of Philadelphia Research Institute, Philadelphia, PA 19104, USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - E. Michael Ostap
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Roberto Dominguez
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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2
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Nietmann P, Kaub K, Suchenko A, Stenz S, Warnecke C, Balasubramanian MK, Janshoff A. Cytosolic actin isoforms form networks with different rheological properties that indicate specific biological function. Nat Commun 2023; 14:7989. [PMID: 38042893 PMCID: PMC10693642 DOI: 10.1038/s41467-023-43653-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 11/15/2023] [Indexed: 12/04/2023] Open
Abstract
The implications of the existence of different actins expressed in epithelial cells for network mechanics and dynamics is investigated by microrheology and confocal imaging. γ-actin predominately found in the apical cortex forms stiffer networks compared to β-actin, which is preferentially organized in stress fibers. We attribute this to selective interactions with Mg2+-ions interconnecting the filaments' N-termini. Bundling propensity of the isoforms is different in the presence of Mg2+-ions, while crosslinkers such as α-actinin, fascin, and heavy meromyosin alter the mechanical response independent of the isoform. In the presence of myosin, β-actin networks show a large number of small contraction foci, while γ-actin displays larger but fewer foci indicative of a stronger interaction with myosin motors. We infer that subtle changes in the amino acid sequence of actin isoforms lead to alterations of the mechanical properties on the network level with potential implications for specific biological functions.
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Affiliation(s)
- Peter Nietmann
- Institute of Physical Chemistry, University of Goettingen, Tammannstr. 6, Göttingen, 37077, Germany
| | - Kevin Kaub
- Institute of Physical Chemistry, University of Goettingen, Tammannstr. 6, Göttingen, 37077, Germany
- Max Planck School Matter to Life, Max Planck Institute for Medical Research, Jahnstr. 29, Heidelberg, 69120, Germany
| | - Andrejus Suchenko
- Warwick Medical School, University of Warwick, Coventry, CV4 7AL, UK
| | - Susanne Stenz
- Institute of Physical Chemistry, University of Goettingen, Tammannstr. 6, Göttingen, 37077, Germany
| | - Claas Warnecke
- Institute of Physical Chemistry, University of Goettingen, Tammannstr. 6, Göttingen, 37077, Germany
| | | | - Andreas Janshoff
- Institute of Physical Chemistry, University of Goettingen, Tammannstr. 6, Göttingen, 37077, Germany.
- Max Planck School Matter to Life, Max Planck Institute for Medical Research, Jahnstr. 29, Heidelberg, 69120, Germany.
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3
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Bai Y, Zhao F, Wu T, Chen F, Pang X. Actin polymerization and depolymerization in developing vertebrates. Front Physiol 2023; 14:1213668. [PMID: 37745245 PMCID: PMC10515290 DOI: 10.3389/fphys.2023.1213668] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/22/2023] [Indexed: 09/26/2023] Open
Abstract
Development is a complex process that occurs throughout the life cycle. F-actin, a major component of the cytoskeleton, is essential for the morphogenesis of tissues and organs during development. F-actin is formed by the polymerization of G-actin, and the dynamic balance of polymerization and depolymerization ensures proper cellular function. Disruption of this balance results in various abnormalities and defects or even embryonic lethality. Here, we reviewed recent findings on the structure of G-actin and F-actin and the polymerization of G-actin to F-actin. We also focused on the functions of actin isoforms and the underlying mechanisms of actin polymerization/depolymerization in cellular and organic morphogenesis during development. This information will extend our understanding of the role of actin polymerization in the physiologic or pathologic processes during development and may open new avenues for developing therapeutics for embryonic developmental abnormalities or tissue regeneration.
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Affiliation(s)
- Yang Bai
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Feng Zhao
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Tingting Wu
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Fangchun Chen
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Xiaoxiao Pang
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
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4
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Chang YH. Impact of Protein N α-Modifications on Cellular Functions and Human Health. Life (Basel) 2023; 13:1613. [PMID: 37511988 PMCID: PMC10381334 DOI: 10.3390/life13071613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 07/14/2023] [Accepted: 07/17/2023] [Indexed: 07/30/2023] Open
Abstract
Most human proteins are modified by enzymes that act on the α-amino group of a newly synthesized polypeptide. Methionine aminopeptidases can remove the initiator methionine and expose the second amino acid for further modification by enzymes responsible for myristoylation, acetylation, methylation, or other chemical reactions. Specific acetyltransferases can also modify the initiator methionine and sometimes the acetylated methionine can be removed, followed by further modifications. These modifications at the protein N-termini play critical roles in cellular protein localization, protein-protein interaction, protein-DNA interaction, and protein stability. Consequently, the dysregulation of these modifications could significantly change the development and progression status of certain human diseases. The focus of this review is to highlight recent progress in our understanding of the roles of these modifications in regulating protein functions and how these enzymes have been used as potential novel therapeutic targets for various human diseases.
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Affiliation(s)
- Yie-Hwa Chang
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University Medical School, Saint Louis, MO 63104, USA
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5
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Haarer BK, Pimm ML, de Jong EP, Amberg DC, Henty-Ridilla JL. Purification of human β- and γ-actin from budding yeast. J Cell Sci 2023; 136:jcs260540. [PMID: 37070275 PMCID: PMC10184827 DOI: 10.1242/jcs.260540] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 04/04/2023] [Indexed: 04/19/2023] Open
Abstract
Biochemical studies of human actin and its binding partners rely heavily on abundant and easily purified α-actin from skeletal muscle. Therefore, muscle actin has been used to evaluate and determine the activities of most actin regulatory proteins but there is an underlying concern that these proteins perform differently from actin present in non-muscle cells. To provide easily accessible and relatively abundant sources of human β- or γ-actin (i.e. cytoplasmic actins), we developed Saccharomyces cerevisiae strains that express each as their sole source of actin. Both β- or γ-actin purified in this system polymerize and interact with various binding partners, including profilin, mDia1 (formin), fascin and thymosin-β4 (Tβ4). Notably, Tβ4 and profilin bind to β- or γ-actin with higher affinity than to α-actin, emphasizing the value of testing actin ligands with specific actin isoforms. These reagents will make specific isoforms of actin more accessible for future studies on actin regulation.
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Affiliation(s)
- Brian K. Haarer
- Department of Biochemistry and Molecular Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY 13210, USA
| | - Morgan L. Pimm
- Department of Biochemistry and Molecular Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY 13210, USA
| | | | - David C. Amberg
- Department of Biochemistry and Molecular Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY 13210, USA
| | - Jessica L. Henty-Ridilla
- Department of Biochemistry and Molecular Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY 13210, USA
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
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6
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Chin SM, Hatano T, Sivashanmugam L, Suchenko A, Kashina AS, Balasubramanian MK, Jansen S. N-terminal acetylation and arginylation of actin determines the architecture and assembly rate of linear and branched actin networks. J Biol Chem 2022; 298:102518. [PMID: 36152749 PMCID: PMC9597890 DOI: 10.1016/j.jbc.2022.102518] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 09/16/2022] [Accepted: 09/17/2022] [Indexed: 11/27/2022] Open
Abstract
The great diversity in actin network architectures and dynamics is exploited by cells to drive fundamental biological processes, including cell migration, endocytosis, and cell division. While it is known that this versatility is the result of the many actin-remodeling activities of actin-binding proteins, such as Arp2/3 and cofilin, recent work also implicates posttranslational acetylation or arginylation of the actin N terminus itself as an equally important regulatory mechanism. However, the molecular mechanisms by which acetylation and arginylation alter the properties of actin are not well understood. Here, we directly compare how processing and modification of the N terminus of actin affects its intrinsic polymerization dynamics and its remodeling by actin-binding proteins that are essential for cell migration. We find that in comparison to acetylated actin, arginylated actin reduces intrinsic as well as formin-mediated elongation and Arp2/3-mediated nucleation. By contrast, there are no significant differences in cofilin-mediated severing. Taken together, these results suggest that cells can employ these differently modified actins to regulate actin dynamics. In addition, unprocessed actin with an N-terminal methionine residue shows very different effects on formin-mediated elongation, Arp2/3-mediated nucleation, and severing by cofilin. Altogether, this study shows that the nature of the N terminus of actin can promote distinct actin network dynamics, which can be differentially used by cells to locally finetune actin dynamics at distinct cellular locations, such as at the leading edge.
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Affiliation(s)
- Samantha M Chin
- Department of Cell Biology and Physiology, Washington University in St Louis, Saint Louis, Missouri, USA
| | - Tomoyuki Hatano
- Centre for Mechanochemical Cell Biology and Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Lavanya Sivashanmugam
- Centre for Mechanochemical Cell Biology and Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Andrejus Suchenko
- Centre for Mechanochemical Cell Biology and Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Anna S Kashina
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mohan K Balasubramanian
- Centre for Mechanochemical Cell Biology and Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Silvia Jansen
- Department of Cell Biology and Physiology, Washington University in St Louis, Saint Louis, Missouri, USA.
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7
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A solution to the long-standing problem of actin expression and purification. Proc Natl Acad Sci U S A 2022; 119:e2209150119. [PMID: 36197995 PMCID: PMC9565351 DOI: 10.1073/pnas.2209150119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Actin is the most abundant protein in the cytoplasm of eukaryotic cells and interacts with hundreds of proteins to perform essential functions, including cell motility and cytokinesis. Numerous diseases are caused by mutations in actin, but studying the biochemistry of actin mutants is difficult without a reliable method to obtain recombinant actin. Moreover, biochemical studies have typically used tissue-purified α-actin, whereas humans express six isoforms that are nearly identical but perform specialized functions and are difficult to obtain in isolation from natural sources. Here, we describe a solution to the problem of actin expression and purification. We obtain high yields of actin isoforms in human Expi293F cells. Experiments along the multistep purification protocol demonstrate the removal of endogenous actin and the functional integrity of recombinant actin isoforms. Proteomics analysis of endogenous vs. recombinant actin isoforms confirms the presence of native posttranslational modifications, including N-terminal acetylation achieved after affinity-tag removal using the actin-specific enzyme Naa80. The method described facilitates studies of actin under fully native conditions to determine differences among isoforms and the effects of disease-causing mutations that occur in all six isoforms.
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8
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Weidenhausen J, Kopp J, Ruger-Herreros C, Stein F, Haberkant P, Lapouge K, Sinning I. Extended N-Terminal Acetyltransferase Naa50 in Filamentous Fungi Adds to Naa50 Diversity. Int J Mol Sci 2022; 23:ijms231810805. [PMID: 36142717 PMCID: PMC9500918 DOI: 10.3390/ijms231810805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/09/2022] [Accepted: 09/13/2022] [Indexed: 11/16/2022] Open
Abstract
Most eukaryotic proteins are N-terminally acetylated by a set of Nα acetyltransferases (NATs). This ancient and ubiquitous modification plays a fundamental role in protein homeostasis, while mutations are linked to human diseases and phenotypic defects. In particular, Naa50 features species-specific differences, as it is inactive in yeast but active in higher eukaryotes. Together with NatA, it engages in NatE complex formation for cotranslational acetylation. Here, we report Naa50 homologs from the filamentous fungi Chaetomium thermophilum and Neurospora crassa with significant N- and C-terminal extensions to the conserved GNAT domain. Structural and biochemical analyses show that CtNaa50 shares the GNAT structure and substrate specificity with other homologs. However, in contrast to previously analyzed Naa50 proteins, it does not form NatE. The elongated N-terminus increases Naa50 thermostability and binds to dynein light chain protein 1, while our data suggest that conserved positive patches in the C-terminus allow for ribosome binding independent of NatA. Our study provides new insights into the many facets of Naa50 and highlights the diversification of NATs during evolution.
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Affiliation(s)
- Jonas Weidenhausen
- Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany
| | - Jürgen Kopp
- Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany
| | - Carmen Ruger-Herreros
- Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany
- Center for Molecular Biology of the University of Heidelberg (ZMBH), 69120 Heidelberg, Germany
| | - Frank Stein
- Proteomics Core Facility, EMBL Heidelberg, 69117 Heidelberg, Germany
| | - Per Haberkant
- Proteomics Core Facility, EMBL Heidelberg, 69117 Heidelberg, Germany
| | - Karine Lapouge
- Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany
- Protein Expression and Purification Core Facility, EMBL Heidelberg, 69117 Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), 69120 Heidelberg, Germany
- Correspondence:
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9
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Protein N-Terminal Acetylation: Structural Basis, Mechanism, Versatility, and Regulation. Trends Biochem Sci 2020; 46:15-27. [PMID: 32912665 DOI: 10.1016/j.tibs.2020.08.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 08/03/2020] [Accepted: 08/06/2020] [Indexed: 12/15/2022]
Abstract
N-terminal acetylation (NTA) is one of the most widespread protein modifications, which occurs on most eukaryotic proteins, but is significantly less common on bacterial and archaea proteins. This modification is carried out by a family of enzymes called N-terminal acetyltransferases (NATs). To date, 12 NATs have been identified, harboring different composition, substrate specificity, and in some cases, modes of regulation. Recent structural and biochemical analysis of NAT proteins allows for a comparison of their molecular mechanisms and modes of regulation, which are described here. Although sharing an evolutionarily conserved fold and related catalytic mechanism, each catalytic subunit uses unique elements to mediate substrate-specific activity, and use NAT-type specific auxiliary and regulatory subunits, for their cellular functions.
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10
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Rebowski G, Boczkowska M, Drazic A, Ree R, Goris M, Arnesen T, Dominguez R. Mechanism of actin N-terminal acetylation. SCIENCE ADVANCES 2020; 6:eaay8793. [PMID: 32284999 PMCID: PMC7141826 DOI: 10.1126/sciadv.aay8793] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Accepted: 01/14/2020] [Indexed: 06/11/2023]
Abstract
About 80% of human proteins are amino-terminally acetylated (Nt-acetylated) by one of seven Nt-acetyltransferases (NATs). Actin, the most abundant protein in the cytoplasm, has its own dedicated NAT, NAA80, which acts posttranslationally and affects cytoskeleton assembly and cell motility. Here, we show that NAA80 does not associate with filamentous actin in cells, and its natural substrate is the monomeric actin-profilin complex, consistent with Nt-acetylation preceding polymerization. NAA80 Nt-acetylates actin-profilin much more efficiently than actin alone, suggesting that profilin acts as a chaperone for actin Nt-acetylation. We determined crystal structures of the NAA80-actin-profilin ternary complex, representing different actin isoforms and different states of the catalytic reaction and revealing the first structure of NAT-substrate complex at atomic resolution. The structural, biochemical, and cellular analysis of mutants shows how NAA80 has evolved to specifically recognize actin among all cellular proteins while targeting all six actin isoforms, which differ the most at the amino terminus.
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Affiliation(s)
- Grzegorz Rebowski
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Malgorzata Boczkowska
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Adrian Drazic
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Rasmus Ree
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Marianne Goris
- Department of Biological Sciences, University of Bergen, Bergen, Norway
| | - Thomas Arnesen
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Department of Biological Sciences, University of Bergen, Bergen, Norway
- Department of Surgery, Haukeland University Hospital, Bergen, Norway
| | - Roberto Dominguez
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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11
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Kashina AS. Regulation of actin isoforms in cellular and developmental processes. Semin Cell Dev Biol 2020; 102:113-121. [PMID: 32001148 DOI: 10.1016/j.semcdb.2019.12.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 12/02/2019] [Accepted: 12/02/2019] [Indexed: 12/18/2022]
Abstract
Actin is one of the most abundant and essential intracellular proteins that mediates nearly every form of cellular movement and underlies such key processes as embryogenesis, tissue integrity, cell division and contractility of all types of muscle and non-muscle cells. In mammals, actin is represented by six isoforms, which are encoded by different genes but produce proteins that are 95-99 % identical to each other. The six actin genes have vastly different functions in vivo, and the small amino acid differences between the proteins they encode are rigorously maintained through evolution, but the underlying differences behind this distinction, as well as the importance of specific amino acid sequences for each actin isoform, are not well understood. This review summarizes different levels of actin isoform-specific regulation in cellular and developmental processes, starting with the nuclear actin's role in transcription, and covering the gene-level, mRNA-level, and protein-level regulation, with a special focus on mammalian actins in non-muscle cells.
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Affiliation(s)
- Anna S Kashina
- University of Pennsylvania, Philadelphia, PA, 19104, United States.
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12
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Eldeeb MA, Fahlman RP, Ragheb MA, Esmaili M. Does N‐Terminal Protein Acetylation Lead to Protein Degradation? Bioessays 2019; 41:e1800167. [DOI: 10.1002/bies.201800167] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2018] [Revised: 08/12/2019] [Indexed: 12/29/2022]
Affiliation(s)
- Mohamed A. Eldeeb
- Department of Chemistry (Biochemistry Division)Faculty of ScienceCairo University Giza 12613 Egypt
- Department of Neurology and NeurosurgeryMontreal Neurological InstituteMcGill University Montreal Quebec H3A 2B4 Canada
| | - Richard P. Fahlman
- Department of BiochemistryUniversity of Alberta Edmonton Alberta T6G 2R3 Canada
| | - Mohamed A. Ragheb
- Department of Chemistry (Biochemistry Division)Faculty of ScienceCairo University Giza 12613 Egypt
| | - Mansoore Esmaili
- Department of BiochemistryUniversity of Alberta Edmonton Alberta T6G 2R3 Canada
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13
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A M, Fung TS, Kettenbach AN, Chakrabarti R, Higgs HN. A complex containing lysine-acetylated actin inhibits the formin INF2. Nat Cell Biol 2019; 21:592-602. [PMID: 30962575 PMCID: PMC6501848 DOI: 10.1038/s41556-019-0307-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2018] [Accepted: 02/28/2019] [Indexed: 11/10/2022]
Abstract
Inverted formin 2 (INF2) is a member of the formin family of actin assembly factors. Dominant missense mutations in INF2 are linked to two diseases: focal segmental glomerulosclerosis, a kidney disease, and Charcot-Marie-Tooth disease, a neuropathy. All of the disease mutations map to the autoinhibitory diaphanous inhibitory domain. Interestingly, purified INF2 is not autoinhibited, suggesting the existence of other cellular inhibitors. Here, we purified an INF2 inhibitor from mouse brain tissue, and identified it as a complex of lysine-acetylated actin (KAc-actin) and cyclase-associated protein (CAP). Inhibition of INF2 by CAP-KAc-actin is dependent on the INF2 diaphanous inhibitory domain (DID). Treatment of CAP-KAc-actin-inhibited INF2 with histone deacetylase 6 releases INF2 inhibition, whereas inhibitors of histone deacetylase 6 block the activation of cellular INF2. Disease-associated INF2 mutants are poorly inhibited by CAP-KAc-actin, suggesting that focal segmental glomerulosclerosis and Charcot-Marie-Tooth disease result from reduced CAP-KAc-actin binding. These findings reveal a role for KAc-actin in the regulation of an actin assembly factor by a mechanism that we call facilitated autoinhibition.
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Affiliation(s)
- Mu A
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Tak Shun Fung
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Arminja N Kettenbach
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Rajarshi Chakrabarti
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Henry N Higgs
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA.
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