1
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Mitra A, Deats SP, Dickson PE, Zhu J, Gardin J, Nieman BJ, Henkelman RM, Tsai NP, Chesler EJ, Zhang ZW, Kumar V. Tmod2 Is a Regulator of Cocaine Responses through Control of Striatal and Cortical Excitability and Drug-Induced Plasticity. J Neurosci 2024; 44:e1389232024. [PMID: 38508714 PMCID: PMC11063827 DOI: 10.1523/jneurosci.1389-23.2024] [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: 06/27/2023] [Revised: 02/12/2024] [Accepted: 02/24/2024] [Indexed: 03/22/2024] Open
Abstract
Drugs of abuse induce neuroadaptations, including synaptic plasticity, that are critical for transition to addiction, and genes and pathways that regulate these neuroadaptations are potential therapeutic targets. Tropomodulin 2 (Tmod2) is an actin-regulating gene that plays an important role in synapse maturation and dendritic arborization and has been implicated in substance abuse and intellectual disability in humans. Here, we mine the KOMP2 data and find that Tmod2 knock-out mice show emotionality phenotypes that are predictive of addiction vulnerability. Detailed addiction phenotyping shows that Tmod2 deletion does not affect the acute locomotor response to cocaine administration. However, sensitized locomotor responses are highly attenuated in these knock-outs, indicating perturbed drug-induced plasticity. In addition, Tmod2 mutant animals do not self-administer cocaine indicating lack of hedonic responses to cocaine. Whole-brain MR imaging shows differences in brain volume across multiple regions, although transcriptomic experiments did not reveal perturbations in gene coexpression networks. Detailed electrophysiological characterization of Tmod2 KO neurons showed increased spontaneous firing rate of early postnatal and adult cortical and striatal neurons. Cocaine-induced synaptic plasticity that is critical for sensitization is either missing or reciprocal in Tmod2 KO nucleus accumbens shell medium spiny neurons, providing a mechanistic explanation of the cocaine response phenotypes. Combined, these data, collected from both males and females, provide compelling evidence that Tmod2 is a major regulator of plasticity in the mesolimbic system and regulates the reinforcing and addictive properties of cocaine.
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Affiliation(s)
| | | | | | - Jiuhe Zhu
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | | | - Brian J Nieman
- Mouse Imaging Centre and Translational Medicine, Hospital for Sick Children; Ontario Institute for Cancer Research; Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5T 3H7, Canada
| | - R Mark Henkelman
- Mouse Imaging Centre and Translational Medicine, Hospital for Sick Children; Ontario Institute for Cancer Research; Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5T 3H7, Canada
| | - Nien-Pei Tsai
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | | | | | - Vivek Kumar
- The Jackson Laboratory, Bar Harbor, Maine 04609
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2
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Logvinov AS, Nefedova VV, Yampolskaya DS, Kleymenov SY, Levitsky DI, Matyushenko AM. Structural and Functional Properties of Tropomyosin Isoforms Tpm4.1 and Tpm2.1. BIOCHEMISTRY. BIOKHIMIIA 2023; 88:801-809. [PMID: 37748876 DOI: 10.1134/s0006297923060081] [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: 03/28/2023] [Revised: 05/05/2023] [Accepted: 05/10/2023] [Indexed: 09/27/2023]
Abstract
Tropomyosin (Tpm) is one of the most important partners of actin filament that largely determines its properties. In animal organisms, there are different isoforms of Tpm, which are believed to be involved in the regulation of various cellular functions. However, molecular mechanisms by which various Tpm cytoplasmic regulate of the functioning of actin filaments are still poorly understood. Here, we investigated the properties of Tpm2.1 and Tpm4.1 isoforms and compared them to each other and to more extensively studied Tpm isoforms. Tpm2.1 and Tpm4.1 were very similar in their affinity to F-actin, thermal stability, and resistance to limited proteolysis by trypsin, but differed markedly in the viscosity of their solutions and thermal stability of their complexes with F-actin. The main difference of Tpm2.1 and Tpm4.1 from other Tpm isoforms (e.g., Tpm1.6 and Tpm1.7) was their extremely low thermal stability as measured by the CD and DSC methods. We suggested the possible causes of this instability based on comparing the amino acid sequences of Tpm4.1 and Tpm2.1 with the sequences of Tpm1.6 and Tpm1.7 isoforms, respectively, that have similar exon structure.
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Affiliation(s)
- Andrey S Logvinov
- Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia
- Faculty of Biology, Lomonosov Moscow State University, Moscow, 119991, Russia
| | - Victoria V Nefedova
- Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia
| | - Daria S Yampolskaya
- Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia
| | - Sergey Y Kleymenov
- Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, 119334, Russia
| | - Dmitrii I Levitsky
- Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia
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3
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Rajan S, Kudryashov DS, Reisler E. Actin Bundles Dynamics and Architecture. Biomolecules 2023; 13:450. [PMID: 36979385 PMCID: PMC10046292 DOI: 10.3390/biom13030450] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Revised: 02/16/2023] [Accepted: 02/20/2023] [Indexed: 03/04/2023] Open
Abstract
Cells use the actin cytoskeleton for many of their functions, including their division, adhesion, mechanosensing, endo- and phagocytosis, migration, and invasion. Actin bundles are the main constituent of actin-rich structures involved in these processes. An ever-increasing number of proteins that crosslink actin into bundles or regulate their morphology is being identified in cells. With recent advances in high-resolution microscopy and imaging techniques, the complex process of bundles formation and the multiple forms of physiological bundles are beginning to be better understood. Here, we review the physiochemical and biological properties of four families of highly conserved and abundant actin-bundling proteins, namely, α-actinin, fimbrin/plastin, fascin, and espin. We describe the similarities and differences between these proteins, their role in the formation of physiological actin bundles, and their properties-both related and unrelated to their bundling abilities. We also review some aspects of the general mechanism of actin bundles formation, which are known from the available information on the activity of the key actin partners involved in this process.
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Affiliation(s)
- Sudeepa Rajan
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Dmitri S. Kudryashov
- Department of Chemistry and Biochemistry, Ohio State University, Columbus, OH 43210, USA
| | - Emil Reisler
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
- Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA
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4
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Chen B, Wang M, Qiu J, Liao K, Zhang W, Lv Q, Ma C, Qian Z, Shi Z, Liang R, Lin Y, Ye J, Qiu Y, Lin Y. Cleavage of tropomodulin-3 by asparagine endopeptidase promotes cancer malignancy by actin remodeling and SND1/RhoA signaling. J Exp Clin Cancer Res 2022; 41:209. [PMID: 35765111 PMCID: PMC9238189 DOI: 10.1186/s13046-022-02411-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 06/07/2022] [Indexed: 12/12/2022] Open
Abstract
Abstract
Background
Abnormal proliferation and migration of cells are hallmarks of cancer initiation and malignancy. Asparagine endopeptidase (AEP) has specific substrate cleavage ability and plays a pro-cancer role in a variety of cancers. However, the underlying mechanism of AEP in cancer proliferation and migration still remains unclear.
Methods
Co-immunoprecipitation and following mass spectrometry were used to identify the substrate of AEP. Western blotting was applied to measure the expression of proteins. Single cell/nuclear-sequences were done to detect the heterogeneous expression of Tmod3 in tumor tissues. CCK-8 assay, flow cytometry assays, colony formation assay, Transwell assay and scratch wound-healing assay were performed as cellular functional experiments. Mouse intracranial xenograft tumors were studied in in vivo experiments.
Results
Here we showed that AEP cleaved a ubiquitous cytoskeleton regulatory protein, tropomodulin-3 (Tmod3) at asparagine 157 (N157) and produced two functional truncations (tTmod3-N and tTmod3-C). Truncated Tmod3 was detected in diverse tumors and was found to be associated with poor prognosis of high-grade glioma. Functional studies showed that tTmod3-N and tTmod3-C enhanced cancer cell migration and proliferation, respectively. Animal models further revealed the tumor-promoting effects of AEP truncated Tmod3 in vivo. Mechanistically, tTmod3-N was enriched in the cell cortex and competitively inhibited the pointed-end capping effect of wild-type Tmod3 on filamentous actin (F-actin), leading to actin remodeling. tTmod3-C translocated to the nucleus, where it interacted with Staphylococcal Nuclease And Tudor Domain Containing 1 (SND1), facilitating the transcription of Ras Homolog Family Member A/Cyclin Dependent Kinases (RhoA/CDKs).
Conclusion
The newly identified AEP-Tmod3 protease signaling axis is a novel “dual-regulation” mechanism of tumor cell proliferation and migration. Our work provides new clues to the underlying mechanisms of cancer proliferation and invasive progression and evidence for targeting AEP or Tmod3 for therapy.
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Machado JP, Athie MC, Matos AH, Lopes-Cendes I, Vieira A. The transcriptome of rat hippocampal subfields. IBRO Neurosci Rep 2022; 13:322-329. [PMID: 36247526 PMCID: PMC9561749 DOI: 10.1016/j.ibneur.2022.09.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 11/08/2022] Open
Abstract
The hippocampus comprises several neuronal populations such as CA1, CA2, CA3, and the dentate gyrus (DG), which present different neuronal origins, morphologies, and molecular mechanisms. Laser capture microdissection (LCM) allows selectively collecting samples from target regions and eliminating unwanted cells to obtain more specific results. LCM of hippocampus neuronal populations coupĺed with RNA-seq analysis has the potential to allow the exploration of the molecular machinery unique to each of these subfields. Previous RNA-seq investigation has already provided a molecular blueprint of the hippocampus, however, there is no RNA-seq data specific for each of the rat hippocampal regions. Serial tissue sections covering the hippocampus were produced from frozen brains of adult male Wistar rats, and the hippocampal subfields CA1, CA2, CA3, and DG were identified and isolated by LCM. We found evident segregation of the transcriptomic profile from different regions of the hippocampus and the expression of known, as well as novel, specific marker genes for each region. Gene ontology enrichment analysis of CA1 subfield indicates an enrichment of actin regulation and postsynaptic membrane AMPA receptors genes indispensable for long-term potentiation. CA2 and CA3 transcripts were found associated with the increased metabolic processes. DG expression was enriched for ribosome and spliceosome, both required for protein synthesis and maintenance of cell life. The present findings contribute to a deeper understanding of the differences in the molecular machinery expressed by the rat hippocampal neuronal populations, further exploring underlying mechanisms responsible for each subflied specific functions.
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Affiliation(s)
- João P.D. Machado
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, São Paulo, Brazil
| | - Maria C.P. Athie
- Department of Translational Medicine, School of Medical Sciences. University of Campinas (UNICAMP), Campinas, São Paulo, Brazil,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, São Paulo, Brazil
| | - Alexandre H.B. Matos
- Department of Translational Medicine, School of Medical Sciences. University of Campinas (UNICAMP), Campinas, São Paulo, Brazil,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, São Paulo, Brazil
| | - Iscia Lopes-Cendes
- Department of Translational Medicine, School of Medical Sciences. University of Campinas (UNICAMP), Campinas, São Paulo, Brazil,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, São Paulo, Brazil
| | - André.S. Vieira
- Department of Structural and Functional Biology, Institute of Biology, University of Campinas (UNICAMP), Campinas, São Paulo, Brazil,Brazilian Institute of Neuroscience and Neurotechnology (BRAINN), Campinas, São Paulo, Brazil,Correspondence to: Department of Structural and Functional Biology, Institute of Biology, Cidade Universitária “Zeferino Vaz”, University of Campinas, UNICAMP, Rua Monteiro Lobato, 255 - Bloco J - 1 piso - Sl 16, Campinas 13083-862, São Paulo, Brazil.
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6
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Tolkatchev D, Gregorio CC, Kostyukova AS. The role of leiomodin in actin dynamics: a new road or a secret gate. FEBS J 2022; 289:6119-6131. [PMID: 34273242 PMCID: PMC8761783 DOI: 10.1111/febs.16128] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/10/2021] [Accepted: 07/16/2021] [Indexed: 12/29/2022]
Abstract
Leiomodin is an important emerging regulator of thin filaments. As novel molecular, cellular, animal model, and human data accumulate, the mechanisms of its action become clearer. Structural studies played a significant part in understanding the functional significance of leiomodin's interacting partners and functional domains. In this review, we present the current state of knowledge on the structural and cellular properties of leiomodin which has led to two proposed mechanisms of its function. Although it is known that leiomodin is essential for life, numerous domains within leiomodin remain unstudied and as such, we outline future directions for investigations that we predict will provide evidence that leiomodin is a multifunctional protein.
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Affiliation(s)
- Dmitri Tolkatchev
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164, USA
| | - Carol C. Gregorio
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ 85724, USA
| | - Alla S. Kostyukova
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA 99164, USA
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7
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Cheng L, Wang X, Chou H, Liu T, Fu H, Li G. Proteomic Sequencing of Stellate Ganglions in Rabbits With Myocardial Infarction. Front Physiol 2021; 12:687424. [PMID: 34975513 PMCID: PMC8716754 DOI: 10.3389/fphys.2021.687424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 11/17/2021] [Indexed: 11/20/2022] Open
Abstract
The stellate ganglion (SG) of the autonomic nervous system plays important role in cardiovascular diseases (CDs). Myocardial infarction (MI) is associated with sustained increasing cardiac sympathetic nerve activity. Expressions and functions of proteins in SG tissue after MI are remaining unclear. This study is to explore the expression characteristics of proteins in SGs associated with MI. Japanese big-ear white rabbits (n = 22) were randomly assigned to the control group and MI group. The MI model was established by left anterior descending coronary artery ligation and confirmed by serum myocardial enzymes increasing 2,3,5-triphenyltetrazolium (TTC) staining and echocardiography. The expressions of proteins in rabbit SGs after MI were detected using tandem mass tags (TMT) quantitative proteomic sequencing. There were 3,043 credible proteins were predicted in rabbit SG tissues and 383 differentially expressed proteins (DEPs) including 143 upregulated and 240 downregulated proteins. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the DEPs involved in adrenergic signaling in cardiomyocytes, positive regulation of ERK1 and ERK2 cascade, and other biological processes. Three kinds of proteins directly correlated to CDs were selected to be validated by the subsequent western blot experiment. This study first identified the characterization of proteins in rabbit SG after MI, which laid a solid foundation for revealing the mechanism of roles of SG on the MI process.
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8
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Marchenko MA, Nefedova VV, Yampolskaya DS, Borzova VA, Kleymenov SY, Nabiev SR, Nikitina LV, Matyushenko AM, Levitsky DI. Comparative structural and functional studies of low molecular weight tropomyosin isoforms, the TPM3 gene products. Arch Biochem Biophys 2021; 710:108999. [PMID: 34339666 DOI: 10.1016/j.abb.2021.108999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 07/06/2021] [Accepted: 07/20/2021] [Indexed: 10/20/2022]
Abstract
Tropomyosin (Tpm) is an actin-associated protein and key regulator of actin filament structure and dynamics in muscle and non-muscle cells where it participates in many vital processes. Human non-muscle cells produce many Tpm isoforms; however, little is known yet about their structural and functional properties. In the present work, we have applied various methods to investigate the properties of five low molecular weight Tpm isoforms (Tpm3.1, Tpm3.2, Tpm3.4, Tpm3.5, and Tpm3.7), the products of TPM3 gene, which significantly differ by alternatively spliced internal exon 6 (6a or 6b) and C-terminal exon 9 (9a, 9c or 9d). Our results clearly demonstrate that the properties of these Tpm isoforms are quite different depending on sequence variations in alternatively spliced regions of their molecules. These differences can be important in further studies to explain why these Tpm isoforms play a key role in organization and dynamics of the cytoskeleton.
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Affiliation(s)
- Marina A Marchenko
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, 119071, Moscow, Russia; Department of Biochemistry, School of Biology, Moscow State University, Moscow, 119234, Russia
| | - Victoria V Nefedova
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, 119071, Moscow, Russia
| | - Daria S Yampolskaya
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, 119071, Moscow, Russia
| | - Vera A Borzova
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, 119071, Moscow, Russia
| | - Sergey Y Kleymenov
- Koltzov Institute of Developmental Biology of the Russian Academy of Sciences, 119334, Moscow, Russia
| | - Salavat R Nabiev
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg, 620049, Russia
| | - Larisa V Nikitina
- Institute of Immunology and Physiology, Russian Academy of Sciences, Yekaterinburg, 620049, Russia
| | - Alexander M Matyushenko
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, 119071, Moscow, Russia
| | - Dmitrii I Levitsky
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, 119071, Moscow, Russia.
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9
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Marchenko M, Nefedova V, Artemova N, Kleymenov S, Levitsky D, Matyushenko A. Structural and Functional Peculiarities of Cytoplasmic Tropomyosin Isoforms, the Products of TPM1 and TPM4 Genes. Int J Mol Sci 2021; 22:ijms22105141. [PMID: 34067970 PMCID: PMC8152229 DOI: 10.3390/ijms22105141] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 04/30/2021] [Accepted: 05/09/2021] [Indexed: 12/26/2022] Open
Abstract
Tropomyosin (Tpm) is one of the major protein partners of actin. Tpm molecules are α-helical coiled-coil protein dimers forming a continuous head-to-tail polymer along the actin filament. Human cells produce a large number of Tpm isoforms that are thought to play a significant role in determining actin cytoskeletal functions. Even though the role of these Tpm isoforms in different non-muscle cells is more or less studied in many laboratories, little is known about their structural and functional properties. In the present work, we have applied various methods to investigate the properties of five cytoplasmic Tpm isoforms (Tpm1.5, Tpm 1.6, Tpm1.7, Tpm1.12, and Tpm 4.2), which are the products of two different genes, TPM1 and TPM4, and also significantly differ by alternatively spliced exons: N-terminal exons 1a2b or 1b, internal exons 6a or 6b, and C-terminal exons 9a, 9c or 9d. Our results demonstrate that structural and functional properties of these Tpm isoforms are quite different depending on sequence variations in alternatively spliced regions of their molecules. The revealed differences can be important in further studies to explain why various Tpm isoforms interact uniquely with actin filaments, thus playing an important role in the organization and dynamics of the cytoskeleton.
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Affiliation(s)
- Marina Marchenko
- Research Center of Biotechnology, A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, 119071 Moscow, Russia; (M.M.); (V.N.); (N.A.); (D.L.)
- Department of Biochemistry, School of Biology, Moscow State University, 119234 Moscow, Russia
| | - Victoria Nefedova
- Research Center of Biotechnology, A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, 119071 Moscow, Russia; (M.M.); (V.N.); (N.A.); (D.L.)
| | - Natalia Artemova
- Research Center of Biotechnology, A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, 119071 Moscow, Russia; (M.M.); (V.N.); (N.A.); (D.L.)
| | - Sergey Kleymenov
- Koltzov Institute of Developmental Biology, Russian Academy of Sciences, 119334 Moscow, Russia;
| | - Dmitrii Levitsky
- Research Center of Biotechnology, A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, 119071 Moscow, Russia; (M.M.); (V.N.); (N.A.); (D.L.)
| | - Alexander Matyushenko
- Research Center of Biotechnology, A.N. Bach Institute of Biochemistry, Russian Academy of Sciences, 119071 Moscow, Russia; (M.M.); (V.N.); (N.A.); (D.L.)
- Correspondence: ; Tel.: +7-926-1654430
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10
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Tolkatchev D, Kuruba B, Smith GE, Swain KD, Smith KA, Moroz N, Williams TJ, Kostyukova AS. Structural insights into the tropomodulin assembly at the pointed ends of actin filaments. Protein Sci 2021; 30:423-437. [PMID: 33206408 PMCID: PMC7784754 DOI: 10.1002/pro.4000] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 11/09/2020] [Accepted: 11/13/2020] [Indexed: 11/11/2022]
Abstract
Tropomodulins are a family of important regulators of actin dynamics at the pointed ends of actin filaments. Four isoforms of tropomodulin, Tmod1-Tmod4, are expressed in vertebrates. Binding of tropomodulin to the pointed end is dependent on tropomyosin, an actin binding protein that itself is represented in mammals by up to 40 isoforms. The understanding of the regulatory role of the tropomodulin/tropomyosin molecular diversity has been limited due to the lack of a three-dimensional structure of the tropomodulin/tropomyosin complex. In this study, we mapped tropomyosin residues interacting with two tropomyosin-binding sites of tropomodulin and generated a three-dimensional model of the tropomodulin/tropomyosin complex for each of these sites. The models were refined by molecular dynamics simulations and validated via building a self-consistent three-dimensional model of tropomodulin assembly at the pointed end. The model of the pointed-end Tmod assembly offers new insights in how Tmod binding ensures tight control over the pointed end dynamics.
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Affiliation(s)
- Dmitri Tolkatchev
- Voiland School of Chemical Engineering and BioengineeringWashington State UniversityPullmanWashingtonUSA
| | - Balaganesh Kuruba
- Voiland School of Chemical Engineering and BioengineeringWashington State UniversityPullmanWashingtonUSA
| | - Garry E. Smith
- Voiland School of Chemical Engineering and BioengineeringWashington State UniversityPullmanWashingtonUSA
| | - Kyle D. Swain
- Voiland School of Chemical Engineering and BioengineeringWashington State UniversityPullmanWashingtonUSA
| | - Kaitlin A. Smith
- Voiland School of Chemical Engineering and BioengineeringWashington State UniversityPullmanWashingtonUSA
| | - Natalia Moroz
- Voiland School of Chemical Engineering and BioengineeringWashington State UniversityPullmanWashingtonUSA
- Department of Plant PathologyWashington State UniversityPullmanWashingtonUSA
| | - Trenton J. Williams
- Voiland School of Chemical Engineering and BioengineeringWashington State UniversityPullmanWashingtonUSA
| | - Alla S. Kostyukova
- Voiland School of Chemical Engineering and BioengineeringWashington State UniversityPullmanWashingtonUSA
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11
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Jung M, Kim D, Mun JY. Direct Visualization of Actin Filaments and Actin-Binding Proteins in Neuronal Cells. Front Cell Dev Biol 2020; 8:588556. [PMID: 33324645 PMCID: PMC7726226 DOI: 10.3389/fcell.2020.588556] [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: 07/29/2020] [Accepted: 10/27/2020] [Indexed: 12/15/2022] Open
Abstract
Actin networks and actin-binding proteins (ABPs) are most abundant in the cytoskeleton of neurons. The function of ABPs in neurons is nucleation of actin polymerization, polymerization or depolymerization regulation, bundling of actin through crosslinking or stabilization, cargo movement along actin filaments, and anchoring of actin to other cellular components. In axons, ABP–actin interaction forms a dynamic, deep actin network, which regulates axon extension, guidance, axon branches, and synaptic structures. In dendrites, actin and ABPs are related to filopodia attenuation, spine formation, and synapse plasticity. ABP phosphorylation or mutation changes ABP–actin binding, which regulates axon or dendritic plasticity. In addition, hyperactive ABPs might also be expressed as aggregates of abnormal proteins in neurodegeneration. Those changes cause many neurological disorders. Here, we will review direct visualization of ABP and actin using various electron microscopy (EM) techniques, super resolution microscopy (SRM), and correlative light and electron microscopy (CLEM) with discussion of important ABPs in neuron.
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Affiliation(s)
- Minkyo Jung
- Neural Circuit Research Group, Korea Brain Research Institute, Daegu, South Korea
| | - Doory Kim
- Department of Chemistry, Research Institute for Convergence of Basic Sciences, Institute of Nano Science and Technology, Research Institute for Natural Sciences, Hanyang University, Seoul, South Korea
| | - Ji Young Mun
- Neural Circuit Research Group, Korea Brain Research Institute, Daegu, South Korea
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12
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He Q, Yu F, Cong M, Ji Y, Zhang Q, Ding F. Comparative Proteomic Analysis of Differentially Expressed Proteins between Injured Sensory and Motor Nerves after Peripheral Nerve Transection. J Proteome Res 2020; 20:1488-1508. [PMID: 33284006 DOI: 10.1021/acs.jproteome.0c00639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Peripheral nerve repair and functional recovery depend on the rate of nerve regeneration and the quality of target reinnervation. It is important to fully understand the cellular and molecular basis underlying the specificity of peripheral nerve regeneration, which means achieving corresponding correct pathfinding and accurate target reinnervation for regrowing motor and sensory axons. In this study, a quantitative proteomic technique, based on isobaric tags for relative and absolute quantitation (iTRAQ), was used to profile the protein expression pattern between single motor and sensory nerves at 14 days after peripheral nerve transection. Among a total of 1259 proteins identified, 176 proteins showed the differential expressions between injured motor and sensory nerves. Quantitative RT-PCR and western blot analysis were applied to validate the proteomic data on representative differentially expressed proteins. Functional categorization indicated that differentially expressed proteins were linked to a diverse array of molecular functions, including axonogenesis, response to axon injury, tissue remodeling, axon ensheathment, cell proliferation and adhesion, vesicle-mediated transport, response to oxidative stress, internal signal cascade, and macromolecular complex assembly, which might play an essential role in peripheral motor and sensory nerve regeneration. Overall, we hope that the proteomic database obtained in this study could serve as a solid foundation for the comprehensive investigation of differentially expressed proteins between injured motor and sensory nerves and for the mechanism elucidation of the specificity of peripheral nerve regeneration. Data are available via ProteomeXchange with identifier PXD022097.
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Affiliation(s)
- Qianru He
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, JS 226001, PR China
| | - Fanhui Yu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, JS 226001, PR China
| | - Meng Cong
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, JS 226001, PR China
| | - Yuhua Ji
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, JS 226001, PR China
| | - Qi Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, JS 226001, PR China
| | - Fei Ding
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Nantong University, Nantong, JS 226001, PR China
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13
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Tolkatchev D, Smith GE, Schultz LE, Colpan M, Helms GL, Cort JR, Gregorio CC, Kostyukova AS. Leiomodin creates a leaky cap at the pointed end of actin-thin filaments. PLoS Biol 2020; 18:e3000848. [PMID: 32898131 PMCID: PMC7500696 DOI: 10.1371/journal.pbio.3000848] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 09/18/2020] [Accepted: 08/17/2020] [Indexed: 01/26/2023] Open
Abstract
Improper lengths of actin-thin filaments are associated with altered contractile activity and lethal myopathies. Leiomodin, a member of the tropomodulin family of proteins, is critical in thin filament assembly and maintenance; however, its role is under dispute. Using nuclear magnetic resonance data and molecular dynamics simulations, we generated the first atomic structural model of the binding interface between the tropomyosin-binding site of cardiac leiomodin and the N-terminus of striated muscle tropomyosin. Our structural data indicate that the leiomodin/tropomyosin complex only forms at the pointed end of thin filaments, where the tropomyosin N-terminus is not blocked by an adjacent tropomyosin protomer. This discovery provides evidence supporting the debated mechanism where leiomodin and tropomodulin regulate thin filament lengths by competing for thin filament binding. Data from experiments performed in cardiomyocytes provide additional support for the competition model; specifically, expression of a leiomodin mutant that is unable to interact with tropomyosin fails to displace tropomodulin at thin filament pointed ends and fails to elongate thin filaments. Together with previous structural and biochemical data, we now propose a molecular mechanism of actin polymerization at the pointed end in the presence of bound leiomodin. In the proposed model, the N-terminal actin-binding site of leiomodin can act as a "swinging gate" allowing limited actin polymerization, thus making leiomodin a leaky pointed-end cap. Results presented in this work answer long-standing questions about the role of leiomodin in thin filament length regulation and maintenance.
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Affiliation(s)
- Dmitri Tolkatchev
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington, United States of America
| | - Garry E. Smith
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington, United States of America
| | - Lauren E. Schultz
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, United States of America
| | - Mert Colpan
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, United States of America
| | - Gregory L. Helms
- The Center for NMR Spectroscopy, Washington State University, Pullman, Washington, United States of America
| | - John R. Cort
- Earth and Biological Sciences Directorate, Pacific Northwest National Laboratory, Richland, Washington, United States of America
- Institute of Biological Chemistry, Washington State University, Pullman, Washington, United States of America
| | - Carol C. Gregorio
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, Arizona, United States of America
| | - Alla S. Kostyukova
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, Washington, United States of America
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14
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Abouelezz A, Stefen H, Segerstråle M, Micinski D, Minkeviciene R, Lahti L, Hardeman EC, Gunning PW, Hoogenraad CC, Taira T, Fath T, Hotulainen P. Tropomyosin Tpm3.1 Is Required to Maintain the Structure and Function of the Axon Initial Segment. iScience 2020; 23:101053. [PMID: 32344377 PMCID: PMC7186529 DOI: 10.1016/j.isci.2020.101053] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 03/05/2020] [Accepted: 04/06/2020] [Indexed: 12/26/2022] Open
Abstract
The axon initial segment (AIS) is the site of action potential initiation and serves as a cargo transport filter and diffusion barrier that helps maintain neuronal polarity. The AIS actin cytoskeleton comprises actin patches and periodic sub-membranous actin rings. We demonstrate that tropomyosin isoform Tpm3.1 co-localizes with actin patches and that the inhibition of Tpm3.1 led to a reduction in the density of actin patches. Furthermore, Tpm3.1 showed a periodic distribution similar to sub-membranous actin rings but Tpm3.1 was only partially congruent with sub-membranous actin rings. Nevertheless, the inhibition of Tpm3.1 affected the uniformity of the periodicity of actin rings. Furthermore, Tpm3.1 inhibition led to reduced accumulation of AIS structural and functional proteins, disruption in sorting somatodendritic and axonal proteins, and a reduction in firing frequency. These results show that Tpm3.1 is necessary for the structural and functional maintenance of the AIS. Tropomyosin isoform Tpm3.1 co-localizes with the actin cytoskeleton in the AIS Tpm3.1 inhibition led to a less organized AIS actin cytoskeleton Perturbation of Tpm3.1 function reduced the accumulation of AIS scaffolding proteins Tpm3.1 inhibition compromised cargo sorting and rapidly reduced firing frequency
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Affiliation(s)
- Amr Abouelezz
- Minerva Foundation Institute for Medical Research, Biomedicum Helsinki 2U, Tukholmankatu 8, 00290 Helsinki, Finland; HiLIFE - Neuroscience Center, University of Helsinki, Haartmaninkatu 8, 00290 Helsinki, Finland
| | - Holly Stefen
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Mikael Segerstråle
- Faculty of Biological and Environmental Sciences, University of Helsinki, Viikinkaari 1, 00790 Helsinki, Finland
| | - David Micinski
- Minerva Foundation Institute for Medical Research, Biomedicum Helsinki 2U, Tukholmankatu 8, 00290 Helsinki, Finland
| | - Rimante Minkeviciene
- Minerva Foundation Institute for Medical Research, Biomedicum Helsinki 2U, Tukholmankatu 8, 00290 Helsinki, Finland
| | - Lauri Lahti
- Department of Computer Science, Aalto University School of Science, Espoo, Finland
| | - Edna C Hardeman
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Peter W Gunning
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia
| | - Casper C Hoogenraad
- Cell Biology, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584CH Utrecht, the Netherlands
| | - Tomi Taira
- Faculty of Veterinary Medicine, University of Helsinki, Agnes Sjöbergin katu 2, 00790 Helsinki, Finland
| | - Thomas Fath
- School of Medical Sciences, UNSW Sydney, Sydney, NSW 2052, Australia; Dementia Research Centre, Faculty of Medicine and Health Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Pirta Hotulainen
- Minerva Foundation Institute for Medical Research, Biomedicum Helsinki 2U, Tukholmankatu 8, 00290 Helsinki, Finland.
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15
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Impact of the actin cytoskeleton on cell development and function mediated via tropomyosin isoforms. Semin Cell Dev Biol 2019; 102:122-131. [PMID: 31630997 DOI: 10.1016/j.semcdb.2019.10.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 10/03/2019] [Accepted: 10/04/2019] [Indexed: 01/07/2023]
Abstract
The physiological function of actin filaments is challenging to dissect because of the pleiotropic impact of global disruption of the actin cytoskeleton. Tropomyosin isoforms have provided a unique opportunity to address this issue. A substantial fraction of actin filaments in animal cells consist of co-polymers of actin with specific tropomyosin isoforms which determine the functional capacity of the filament. Genetic manipulation of the tropomyosins has revealed isoform specific roles and identified the physiological function of the different actin filament types based on their tropomyosin isoform composition. Surprisingly, there is remarkably little redundancy between the tropomyosins resulting in highly penetrant impacts of both ectopic overexpression and knockout of isoforms. The physiological roles of the tropomyosins cover a broad range from development and morphogenesis to cell migration and specialised tissue function and human diseases.
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16
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Nefedova VV, Marchenko MA, Kleymenov SY, Datskevich PN, Levitsky DI, Matyushenko AM. Thermal unfolding of various human non-muscle isoforms of tropomyosin. Biochem Biophys Res Commun 2019; 514:613-617. [PMID: 31072616 DOI: 10.1016/j.bbrc.2019.05.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 05/01/2019] [Indexed: 12/25/2022]
Abstract
Tropomyosin (Tpm) is an α-helical coiled-coil protein dimer, which forms a continuous head-to-tail polymer along the actin filament. In striated muscles, Tpm plays an important role in the Ca2+-dependent regulation of muscle contraction. However, little is known about functional and especially structural properties of the numerous non-muscle Tpm isoforms. In the present work, we have applied circular dichroism (CD) and differential scanning calorimetry (DSC) to investigate thermal unfolding and domain structure of various non-muscle human Tpm isoforms. These isoforms, the products of two different genes, TPM1 and TPM3, also significantly differ by alternatively spliced exons: N-terminal exons 1a2b or 1b, internal exons 6a or 6b, and C-terminal exons 9a, 9c or 9d. Our results clearly demonstrate that structural properties of various non-muscle Tpm isoforms can be quite different depending on the presence of different alternatively spliced exons in their genes. These data show for the first time a significant difference in the thermal unfolding between muscle and non-muscle Tpm isoforms and indicate that replacement of alternatively spliced exons alters the stability of certain domains in the Tpm molecule.
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Affiliation(s)
- Victoria V Nefedova
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia
| | - Marina A Marchenko
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia; Department of Biochemistry, School of Biology, Moscow State University, Moscow, 119234, Russia
| | - Sergey Y Kleymenov
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia; Koltzov Institute of Developmental Biology of the Russian Academy of Sciences, Moscow, 119334, Russia
| | - Petr N Datskevich
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia
| | - Dmitrii I Levitsky
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia; A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow, 119234, Russia
| | - Alexander M Matyushenko
- A.N. Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia.
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17
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Parreno J, Fowler VM. Multifunctional roles of tropomodulin-3 in regulating actin dynamics. Biophys Rev 2018; 10:1605-1615. [PMID: 30430457 DOI: 10.1007/s12551-018-0481-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 11/08/2018] [Indexed: 12/12/2022] Open
Abstract
Tropomodulins (Tmods) are proteins that cap the slow-growing (pointed) ends of actin filaments (F-actin). The basis for our current understanding of Tmod function comes from studies in cells with relatively stable and highly organized F-actin networks, leading to the view that Tmod capping functions principally to preserve F-actin stability. However, not only is Tmod capping dynamic, but it also can play major roles in regulating diverse cellular processes involving F-actin remodeling. Here, we highlight the multifunctional roles of Tmod with a focus on Tmod3. Like other Tmods, Tmod3 binds tropomyosin (Tpm) and actin, capping pure F-actin at submicromolar and Tpm-coated F-actin at nanomolar concentrations. Unlike other Tmods, Tmod3 can also bind actin monomers and its ability to bind actin is inhibited by phosphorylation of Tmod3 by Akt2. Tmod3 is ubiquitously expressed and is present in a diverse array of cytoskeletal structures, including contractile structures such as sarcomere-like units of actomyosin stress fibers and in the F-actin network encompassing adherens junctions. Tmod3 participates in F-actin network remodeling in lamellipodia during cell migration and in the assembly of specialized F-actin networks during exocytosis. Furthermore, Tmod3 is required for development, regulating F-actin mesh formation during meiosis I of mouse oocytes, erythroblast enucleation in definitive erythropoiesis, and megakaryocyte morphogenesis in the mouse fetal liver. Thus, Tmod3 plays vital roles in dynamic and stable F-actin networks in cell physiology and development, with further research required to delineate the mechanistic details of Tmod3 regulation in the aforementioned processes, or in other yet to be discovered processes.
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Affiliation(s)
- Justin Parreno
- Department of Molecular Medicine, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA, 92037, USA
| | - Velia M Fowler
- Department of Molecular Medicine, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, CA, 92037, USA.
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18
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Tropomodulin Isoform-Specific Regulation of Dendrite Development and Synapse Formation. J Neurosci 2018; 38:10271-10285. [PMID: 30301754 DOI: 10.1523/jneurosci.3325-17.2018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 09/25/2018] [Accepted: 10/02/2018] [Indexed: 11/21/2022] Open
Abstract
Neurons of the CNS elaborate highly branched dendritic arbors that host numerous dendritic spines, which serve as the postsynaptic platform for most excitatory synapses. The actin cytoskeleton plays an important role in dendrite development and spine formation, but the underlying mechanisms remain incompletely understood. Tropomodulins (Tmods) are a family of actin-binding proteins that cap the slow-growing (pointed) end of actin filaments, thereby regulating the stability, length, and architecture of complex actin networks in diverse cell types. Three members of the Tmod family, Tmod1, Tmod2, and Tmod3 are expressed in the vertebrate CNS, but their function in neuronal development is largely unknown. In this study, we present evidence that Tmod1 and Tmod2 exhibit distinct roles in regulating spine development and dendritic arborization, respectively. Using rat hippocampal tissues from both sexes, we find that Tmod1 and Tmod2 are expressed with distinct developmental profiles: Tmod2 is expressed early during hippocampal development, whereas Tmod1 expression coincides with synaptogenesis. We then show that knockdown of Tmod2, but not Tmod1, severely impairs dendritic branching. Both Tmod1 and Tmod2 are localized to a distinct subspine region where they regulate local F-actin stability. However, the knockdown of Tmod1, but not Tmod2, disrupts spine morphogenesis and impairs synapse formation. Collectively, these findings demonstrate that regulation of the actin cytoskeleton by different members of the Tmod family plays an important role in distinct aspects of dendrite and spine development.SIGNIFICANCE STATEMENT The Tropomodulin family of molecules is best known for controlling the length and stability of actin myofilaments in skeletal muscles. While several Tropomodulin members are expressed in the brain, fundamental knowledge about their role in neuronal function is limited. In this study, we show the unique expression profile and subcellular distribution of Tmod1 and Tmod2 in hippocampal neurons. While both Tmod1 and Tmod2 regulate F-actin stability, we find that they exhibit isoform-specific roles in dendrite development and synapse formation: Tmod2 regulates dendritic arborization, whereas Tmod1 is required for spine development and synapse formation. These findings provide novel insight into the actin regulatory mechanisms underlying neuronal development, thereby shedding light on potential pathways disrupted in a number of neurological disorders.
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19
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Gray KT, Stefen H, Ly TNA, Keller CJ, Colpan M, Wayman GA, Pate E, Fath T, Kostyukova AS. Tropomodulin's Actin-Binding Abilities Are Required to Modulate Dendrite Development. Front Mol Neurosci 2018; 11:357. [PMID: 30356860 PMCID: PMC6190845 DOI: 10.3389/fnmol.2018.00357] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Accepted: 09/11/2018] [Indexed: 01/22/2023] Open
Abstract
There are many unanswered questions about the roles of the actin pointed end capping and actin nucleation by tropomodulins (Tmod) in regulating neural morphology. Previous studies indicate that Tmod1 and Tmod2 regulate morphology of the dendritic arbor and spines. Tmod3, which is expressed in the brain, had only a minor influence on morphology. Although these studies established a defined role of Tmod in regulating dendritic and synaptic morphology, the mechanisms by which Tmods exert these effects are unknown. Here, we overexpressed a series of mutated forms of Tmod1 and Tmod2 with disrupted actin-binding sites in hippocampal neurons and found that Tmod1 and Tmod2 require both of their actin-binding sites to regulate dendritic morphology and dendritic spine shape. Proximity ligation assays (PLAs) indicate that these mutations impact the interaction of Tmod1 and Tmod2 with tropomyosins Tpm3.1 and Tpm3.2. This impact on Tmod/Tpm interaction may contribute to the morphological changes observed. Finally, we use molecular dynamics simulations (MDS) to characterize the structural changes, caused by mutations in the C-terminal helix of the leucine-rich repeat (LRR) domain of Tmod1 and Tmod2 alone and when bound onto actin monomers. Our results expand our understanding of how neurons utilize the different Tmod isoforms in development.
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Affiliation(s)
- Kevin T Gray
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, United States.,Neurodegeneration and Repair Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.,Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, United States
| | - Holly Stefen
- Neurodegeneration and Repair Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.,Neuronal Culture Core Facility, University of New South Wales, Sydney, NSW, Australia
| | - Thu N A Ly
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, United States
| | - Christopher J Keller
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, United States
| | - Mert Colpan
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, United States
| | - Gary A Wayman
- Integrative Physiology and Neuroscience, Washington State University, Pullman, WA, United States
| | - Edward Pate
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, United States
| | - Thomas Fath
- Neurodegeneration and Repair Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.,Neuronal Culture Core Facility, University of New South Wales, Sydney, NSW, Australia.,Dementia Research Centre, Department of Biomedical Sciences, Faculty of Medicine & Health Sciences, Macquarie University, Sydney, NSW, Australia
| | - Alla S Kostyukova
- Voiland School of Chemical Engineering and Bioengineering, Washington State University, Pullman, WA, United States
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20
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Bettinsoli P, Ferrari-Toninelli G, Bonini SA, Guarienti M, Cangelosi D, Varesio L, Memo M. Favorable prognostic role of tropomodulins in neuroblastoma. Oncotarget 2018; 9:27092-27103. [PMID: 29930753 PMCID: PMC6007461 DOI: 10.18632/oncotarget.25491] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 05/07/2018] [Indexed: 12/14/2022] Open
Abstract
Neuroblastoma is a pediatric tumor of the sympatoadrenal lineage of the neural crest characterized by high molecular and clinical heterogeneity, which are the main causes of the poor response to standard multimodal therapy. The identification of new and selective biomarkers is important to improve our knowledge on the mechanisms of neuroblastoma progression and to find the targets for innovative cancer therapies. This study identifies a positive correlation among tropomodulins (TMODs) proteins expression and neuroblastoma progression. TMODs bind the pointed end of actin filaments, regulate polymerization and depolymerization processes modifying actin cytoskeletal dynamic and influencing neuronal development processes. Expression levels of TMODs genes were analyzed in 17 datasets comprising different types of tumors, including neuroblastoma, and it was demonstrated that high levels of tropomodulin1 (TMOD1) and tropomodulin 2 (TMOD2) correlate positively with high survival probability and with favorable clinical and molecular characteristics. Functional studies on neuroblastoma cell lines, showed that TMOD1 knockin induced cell cycle arrest, cell proliferation arrest and a mature functional differentiation. TMOD1 overexpression was responsible for particular cell morphology and biochemical changes which directed cells towards a neuronal favorable differentiation profile. TMOD1 downregulation also induced cell proliferation arrest but caused the loss of mature cell differentiation and promoted the development of neuroendocrine cellular characteristics, delineating an aggressive and unfavorable tumor behavior. Overall, these data indicated that TMODs are favorable prognostic biomarkers in neuroblastoma and we believe that they could contribute to unravel a new pathophysiological mechanism of neuroblastoma resistance contributing to the design of personalized therapeutics opportunities.
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Affiliation(s)
- Paola Bettinsoli
- Department of Molecular and Translational Medicine, University of Brescia Medical School, Brescia, Italy
| | - Giulia Ferrari-Toninelli
- Department of Molecular and Translational Medicine, University of Brescia Medical School, Brescia, Italy
| | - Sara Anna Bonini
- Department of Molecular and Translational Medicine, University of Brescia Medical School, Brescia, Italy
| | - Michela Guarienti
- Department of Molecular and Translational Medicine, University of Brescia Medical School, Brescia, Italy
| | - Davide Cangelosi
- Laboratory of Molecular Biology, Giannina Gaslini Institute, Genova, Italy
| | - Luigi Varesio
- Laboratory of Molecular Biology, Giannina Gaslini Institute, Genova, Italy
| | - Maurizio Memo
- Department of Molecular and Translational Medicine, University of Brescia Medical School, Brescia, Italy
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21
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Suchowerska AK, Fok S, Stefen H, Gunning PW, Hardeman EC, Power J, Fath T. Developmental Profiling of Tropomyosin Expression in Mouse Brain Reveals Tpm4.2 as the Major Post-synaptic Tropomyosin in the Mature Brain. Front Cell Neurosci 2017; 11:421. [PMID: 29311841 PMCID: PMC5743921 DOI: 10.3389/fncel.2017.00421] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 12/14/2017] [Indexed: 12/14/2022] Open
Abstract
Nerve cell connections, formed in the developing brain of mammals, undergo a well-programmed process of maturation with changes in their molecular composition over time. The major structural element at the post-synaptic specialization is the actin cytoskeleton, which is composed of different populations of functionally distinct actin filaments. Previous studies, using ultrastructural and light imaging techniques have established the presence of different actin filament populations at the post-synaptic site. However, it remains unknown, how these different actin filament populations are defined and how their molecular composition changes over time. In the present study, we have characterized changes in a core component of actin filaments, the tropomyosin (Tpm) family of actin-associated proteins from embryonal stage to the adult stage. Using biochemical fractionation of mouse brain tissue, we identified the tropomyosin Tpm4.2 as the major post-synaptic Tpm. Furthermore, we found age-related differences in the composition of Tpms at the post-synaptic compartment. Our findings will help to guide future studies that aim to define the functional properties of actin filaments at different developmental stages in the mammalian brain.
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Affiliation(s)
- Alexandra K Suchowerska
- Neurodegeneration and Repair Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Sandra Fok
- Neurodegeneration and Repair Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Holly Stefen
- Neurodegeneration and Repair Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.,Neuron Culture Core Facility, University of New South Wales, SydneyNSW, Australia
| | - Peter W Gunning
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Edna C Hardeman
- Cellular and Genetic Medicine Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - John Power
- Translational Neuroscience Facility, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Thomas Fath
- Neurodegeneration and Repair Unit, School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.,Neuron Culture Core Facility, University of New South Wales, SydneyNSW, Australia
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