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Abstract
Adjuvant chemotherapy has been carried out for patients with cancer who underwent curative resection, but it is basically not needed for patients without micro-metastatic lesions who undergo a perfectly curative surgical operation. The patients who need adjuvant chemotherapy are defined as those whose micro-metastases cannot be detected by imaging modalities in the other sites of the resective areas, despite curative resection for the primary sites. If biomarkers to efficiently evaluate the metastatic potential of each patient could be developed, we may be able to provide personalized adjuvant chemotherapy in the clinical setting. Actinin-4 (ACTN4, gene name ACTN4) is an actin-bundling protein that we identified in 1998 as a novel molecule involved in cancer invasion and metastasis. Protein overexpression of actinin-4 in cancer cells leads to the invasive phenotype, and patients with gene amplification of ACTN4 have a worse prognosis than patients with a normal copy number in some cancers, including pancreas, lung, and salivary gland cancers. In this review, the biological roles of actinin-4 for cancer invasion and metastasis are summarized, and the potential usefulness of actinin-4 as a biomarker for evaluation of metastatic ability is examined.
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Affiliation(s)
- Kazufumi Honda
- Department of Bioregulation, Institution for Advanced Medical Science, Nippon Medical School
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Mun SA, Park J, Park KR, Lee Y, Kang JY, Park T, Jin M, Yang J, Jun CD, Eom SH. Structural and Biochemical Characterization of EFhd1/Swiprosin-2, an Actin-Binding Protein in Mitochondria. Front Cell Dev Biol 2021; 8:628222. [PMID: 33537316 PMCID: PMC7848108 DOI: 10.3389/fcell.2020.628222] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 12/21/2020] [Indexed: 12/21/2022] Open
Abstract
Ca2+ regulates several cellular functions, including signaling events, energy production, and cell survival. These cellular processes are mediated by Ca2+-binding proteins, such as EF-hand superfamily proteins. Among the EF-hand superfamily proteins, allograft inflammatory factor-1 (AIF-1) and swiprosin-1/EF-hand domain-containing protein 2 (EFhd2) are cytosolic actin-binding proteins. AIF-1 modulates the cytoskeleton and increases the migration of immune cells. EFhd2 is also a cytoskeletal protein implicated in immune cell activation and brain cell functions. EFhd1, a mitochondrial fraternal twin of EFhd2, mediates neuronal and pro-/pre-B cell differentiation and mitoflash activation. Although EFhd1 is important for maintaining mitochondrial morphology and energy synthesis, its mechanism of action remains unclear. Here, we report the crystal structure of the EFhd1 core domain comprising a C-terminus of a proline-rich region, two EF-hand domains, and a ligand mimic helix. Structural comparisons of EFhd1, EFhd2, and AIF-1 revealed similarities in their overall structures. In the structure of the EFhd1 core domain, two Zn2+ ions were observed at the interface of the crystal contact, suggesting the possibility of Zn2+-mediated multimerization. In addition, we found that EFhd1 has Ca2+-independent β-actin-binding and Ca2+-dependent β-actin-bundling activities. These findings suggest that EFhd1, an actin-binding and -bundling protein in the mitochondria, may contribute to the Ca2+-dependent regulation of mitochondrial morphology and energy synthesis.
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Affiliation(s)
- Sang A Mun
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Jongseo Park
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Kyoung Ryoung Park
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju, South Korea.,NuclixBio, Seoul, South Korea
| | - Youngjin Lee
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju, South Korea.,Infection and Immunity Research Laboratory, Metabolic Regulation Research Center, Korea Research Institute of Bioscience and Biotechnology, Daejeon, South Korea
| | - Jung Youn Kang
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Taein Park
- Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju, South Korea.,Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Minwoo Jin
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Jihyeong Yang
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Chang-Duk Jun
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - Soo Hyun Eom
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju, South Korea.,Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju, South Korea
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Morita R, Takaine M, Numata O, Nakano K. Molecular dissection of the actin-binding ability of the fission yeast α-actinin, Ain1, in vitro and in vivo. J Biochem 2017; 162:93-102. [PMID: 28338873 DOI: 10.1093/jb/mvx008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 12/27/2016] [Indexed: 02/02/2023] Open
Abstract
A contractile ring (CR) is involved in cytokinesis in animal and yeast cells. Although several types of actin-bundling proteins associate with F-actin in the CR, their individual roles in the CR have not yet been elucidated in detail. Ain1 is the sole α-actinin homologue in the fission yeast Schizosaccharomyces pombe and specifically localizes to the CR with a high turnover rate. S. pombe cells lacking the ain1+ gene show defects in cytokinesis under stress conditions. We herein investigated the biochemical activity and cellular localization mechanisms of Ain1. Ain1 showed weaker affinity to F-actin in vitro than other actin-bundling proteins in S. pombe. We identified a mutation that presumably loosened the interaction between two calponin-homology domains constituting the single actin-binding domain (ABD) of Ain1, which strengthened the actin-binding activity of Ain1. This mutant protein induced a deformation in the ring shape of the CR. Neither a truncated protein consisting only of an N-terminal ABD nor a truncated protein lacking a C-terminal region containing an EF-hand motif localized to the CR, whereas the latter was involved in the bundling of F-actin in vitro. We herein propose detailed mechanisms for how each part of the molecule is involved in the proper cellular localization and function of Ain1.
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Affiliation(s)
- Rikuri Morita
- Department of Biological Sciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennohdai, Tsukuba, Ibaraki 305-8572, Japan
| | - Masak Takaine
- Department of Biological Sciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennohdai, Tsukuba, Ibaraki 305-8572, Japan
| | - Osamu Numata
- Department of Biological Sciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennohdai, Tsukuba, Ibaraki 305-8572, Japan
| | - Kentaro Nakano
- Department of Biological Sciences, Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennohdai, Tsukuba, Ibaraki 305-8572, Japan
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