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Koike M, Yamashita H, Yutoku Y, Koike A. Molecular cloning, subcellular localization, and rapid recruitment to DNA damage sites of chicken Ku70. Sci Rep 2024; 14:1188. [PMID: 38216643 PMCID: PMC10786929 DOI: 10.1038/s41598-024-51501-0] [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: 09/04/2023] [Accepted: 01/05/2024] [Indexed: 01/14/2024] Open
Abstract
Ku70 is a multifunctional protein with pivotal roles in DNA repair via non-homologous end-joining, V(D)J recombination, telomere maintenance, and neuronal apoptosis control. Nonetheless, its regulatory mechanisms remain elusive. Chicken Ku70 (GdKu70) cDNA has been previously cloned, and DT40 cells expressing it have significantly contributed to critical biological discoveries. GdKu70 features an additional 18 amino acids at its N-terminus compared to mammalian Ku70, the biological significance of which remains uncertain. Here, we show that the 5' flanking sequence of GdKu70 cDNA is not nearly encoded in the chicken genome. Notably, these 18 amino acids result from fusion events involving the NFE2L1 gene on chromosome 27 and the Ku70 gene on chromosome 1. Through experiments using newly cloned chicken Ku70 cDNA and specific antibodies, we demonstrated that Ku70 localizes within the cell nucleus as a heterodimer with Ku80 and promptly accumulates at DNA damage sites following injury. This suggests that the functions and spatiotemporal regulatory mechanisms of Ku70 in chickens closely resemble those in mammals. The insights and resources acquired will contribute to elucidate the various mechanisms by which Ku functions. Meanwhile, caution is advised when interpreting the previous numerous key studies that relied on GdKu70 cDNA and its expressing cells.
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Affiliation(s)
- Manabu Koike
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan.
- Life Science Course, Graduate School of Science and Engineering, Saitama University, 255 Shimo-Okubo, Sakura-ku, Saitama, Saitama, 338-8570, Japan.
| | - Hideji Yamashita
- Department of Food and Life Sciences, School of Agriculture, Tokai University, 9-1-1 Toroku, Higashi-ku, Kumamoto, 862-8652, Japan
| | - Yasutomo Yutoku
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Aki Koike
- Institute for Quantum Medical Science, National Institutes for Quantum Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
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Huang YH, Hsieh DK, Sung HM. Influence of gene position on the expression divergence of oxidative response genes in intraspecific yeast. J Evol Biol 2020; 33:505-511. [PMID: 31919900 DOI: 10.1111/jeb.13584] [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: 09/17/2019] [Revised: 12/10/2019] [Accepted: 12/29/2019] [Indexed: 11/28/2022]
Abstract
Phenotypic variation can arise from differences in the protein coding sequence and in the regulatory elements. However, little is known about the contribution of regulatory difference to the expression divergence, especially the cis and trans regulatory variation to the expression divergence in intraspecific populations. In this study, we used two different yeast strains, BY4743 and RM11-1a/α, to study the regulatory variation to the expression divergence between BY and RM under oxidative stress condition. Our results indicated that the expression divergence of BY and RM is mainly due to trans regulatory variations under both normal and oxidative stress conditions. However, cis regulatory variation seems to play a very important role in oxidative stress response in yeast because 36% of genes showed an increase in cis regulatory variation effect compared with 13% of genes that showed an increase in trans regulatory variation effect after oxidative stress. Our data also indicated that genes located on the longer arm of the chromosomes are more susceptible to cis variation effect under oxidative stress than genes on the shorter arm of the chromosomes.
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Affiliation(s)
- Yi-Hsuan Huang
- Department of Life Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Dai-Keng Hsieh
- Department of Life Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Huang-Mo Sung
- Department of Life Sciences, National Cheng Kung University, Tainan, Taiwan
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Koike M, Yutoku Y, Koike A. Nuclear localization of mouse Ku70 in interphase cells and focus formation of mouse Ku70 at DNA damage sites immediately after irradiation. J Vet Med Sci 2015; 77:1137-42. [PMID: 25947323 PMCID: PMC4591156 DOI: 10.1292/jvms.14-0651] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
To elucidate the mechanisms of DNA repair pathway is critical for developing next-generation radiotherapies and chemotherapeutic drugs for cancer. Ionizing radiation and many chemotherapeutic drugs kill tumor cells mainly by inducing DNA double-strand breaks (DSBs). The classical nonhomologous DNA-end joining (NHEJ) (C-NHEJ) pathway repairs a predominant fraction of DSBs in mammalian cells. The C-NHEJ pathway appears to start with the binding of Ku (heterodimer of Ku70 and Ku80) to DNA break ends. Therefore, recruitment of Ku to DSB sites might play a critical role in regulating NHEJ activity. Indeed, human Ku70 and Ku80 localize in the nuclei and accumulate at microirradiated DSB sites. However, the localization and regulation mechanisms of Ku70 and Ku80 homologues in animal models, such as mice and other species, have not been elucidated in detail, particularly in cells immediately after microirradiation. Here, we show that EYFP-tagged mouse Ku70 localizes in the interphase nuclei of mouse fibroblasts and epithelial cells. Furthermore, our findings indicate that EYFP-mouse Ku70 accumulates with its heterodimeric partner Ku80 immediately at laser-microirradiated DSB sites. We also confirmed that the structure of Ku70 nuclear localization signal (NLS) is highly conserved among various rodent species, such as the mouse, rat, degu and ground squirrel, supporting the idea that NLS is important for the regulation of rodent Ku70 function. Collectively, these results suggest that the mechanisms of regulating the localization and accumulation of Ku70 at DSBs might be well conserved between the mouse and human species.
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Affiliation(s)
- Manabu Koike
- Research Center for Charged Particle Therapy, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan
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KOIKE M, NINOMIYA Y, KOIKE A. Characterization of Ninjurin and TSC22 induction after X-irradiation of normal human skin cells. J Dermatol 2007. [DOI: 10.1111/j.1346-8138.2007.00404.x-i1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Abstract
Chinese hamster ovary (CHO) cells are a prevalent tool in biological research and are among the most widely used host cell lines for production of recombinant therapeutic proteins. While research in other organisms has been revolutionized through the development of DNA sequence-based tools, the lack of comparable genomic resources for the Chinese hamster has impeded similar work in CHO cell lines. A comparative genomics approach, based upon the completely sequenced mouse genome, can facilitate genomic work in this important organism. Using chromosome synteny to define regions of conserved linkage between Chinese hamster and mouse chromosomes, a working scaffold for the Chinese hamster genome has been developed. Mapping CHO and Chinese hamster sequences to the mouse genome creates direct access to relevant information in public databases. Additionally, mapping gene expression data onto a chromosome scaffold affords the ability to interpret information in a genomic context, potentially revealing important structural and regulatory features in the Chinese hamster genome. Further development of this genomic scaffold will provide opportunities to use biomolecular tools for research in CHO cell lines today and will be an asset to future efforts to sequence the Chinese hamster genome.
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Affiliation(s)
- Katie F Wlaschin
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, Minnesota 55455-0132, USA
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Koike M, Sugasawa J, Koike A, Kohno Y. p53 phosphorylation in mouse skin and in vitro human skin model by high-dose-radiation exposure. JOURNAL OF RADIATION RESEARCH 2005; 46:461-8. [PMID: 16394637 DOI: 10.1269/jrr.46.461] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The skin is an external organ that is most frequently exposed to radiation. High-dose radiation initiates and promotes acute radiation injury. Thus, it is important to investigate the influence of high-dose radiation exposure on the skin at the molecular level. The post-translational modification of p53 plays a central role in radiation responses, including apoptosis and cell growth arrest. Although it is well known that ataxia telangiectasia mutated (ATM) kinase and DNA-dependent protein kinase (DNA-PK) can phosphorylate Ser15/Ser18 of p53 in vitro, the post-translational modification pattern and the modifier of p53 in the skin after exposure to high-dose X-rays are not yet well understood. Here we show that the phosphorylation of p53 on Ser15/Ser18, as well as the phosphorylation of histone H2AX on Ser139, was detected in the keratinocytes of the mouse skin and human skin models after high-dose X-ray irradiation. Following high-dose X-ray irradiation, both proteins were also phosphorylated in the skin keratinocytes of both ATM gene knockout mice and DNA-PK-deficient SCID mice.
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Affiliation(s)
- Manabu Koike
- Radiation Hazards Research Group, National Institute of Radiological Sciences, Japan.
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Koike M, Shiomi T, Koike A. Identification of Skin injury-related genes induced by ionizing radiation in human keratinocytes using cDNA microarray. JOURNAL OF RADIATION RESEARCH 2005; 46:173-84. [PMID: 15988135 DOI: 10.1269/jrr.46.173] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
The skin is an external organ that is most frequently exposed to radiation. High-dose radiation initiates and promotes skin cancer and acute radiation injury. It is important to investigate the influence of high-dose radiation exposure on the skin at the molecular level to understand acute radiation injury. To identify genes that are associated with injury caused by high-dose radiation exposure of the skin, we used microarray technology to examine the effect of irradiation on approximately 1000 genes in normal human epidermal keratinocytes at 3 h postirradiation with a cytotoxic dose of X-ray (5 Gy). We found that 16 and 59 genes were up- and down-regulated respectively in the keratinocytes. Several apoptosis-related genes, for example, BAK and TSC-22, and anti-proliferative genes, for example, BTG-1 and BTG-3, were up-regulated. We focused on ATF3 because ATF3 is induced most strongly by X-irradiation, and its function in keratinocytes is unknown. The induction of the ATF3 mRNA and protein in keratinocytes following X-ray was confirmed by RT-PCR and western blot analysis. ATF3 was also induced and accumulated within the nuclei of keratinocytes after X-ray irradiation in vivo and in vitro. Exogenous EYFP-ATF3 also accumulated within the nuclei of keratinocytes. In the transient expression assay, EYFP-ATF3, but not EYFP, induced apoptosis in keratinocytes. Taken together, these results suggest that ATF3 plays a role in apoptosis in keratinocytes and is associated with skin injury caused by ionizing radiation.
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Affiliation(s)
- Manabu Koike
- Radiation Hazards Research Group, National Institute of Radiological Sciences, Chiba, Japan.
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Koike M. Dimerization, translocation and localization of Ku70 and Ku80 proteins. JOURNAL OF RADIATION RESEARCH 2002; 43:223-236. [PMID: 12518983 DOI: 10.1269/jrr.43.223] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The Ku protein is a complex of two subunits, Ku70 and Ku80, and was originally identified as an autoantigen recognized by the sera of patients with autoimmune diseases. The Ku protein plays a key role in multiple nuclear processes, e.g., DNA repair, chromosome maintenance, transcription regulation, and V(D)J recombination. The mechanism underlying the regulation of all the diverse functions of Ku is still unclear, although it seems that Ku is a multifunctional protein that works in nuclei. On the other hand, several studies have reported cytoplasmic or cell surface localization of Ku in various cell types. To clarify the fundamental characteristics of Ku, we have examined the expression, heterodimerization, subcellular localization, chromosome location, and molecular mechanisms of the nuclear transport of Ku70 and Ku80. The mechanism that regulates for nuclear localization of Ku70 and Ku80 appears to play, at least in part, a key role in regulating the physiological function of Ku in vivo.
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Affiliation(s)
- Manabu Koike
- Radiation Hazards Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
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Kuroiwa A, Tsuchiya K, Matsubara K, Namikawa T, Matsuda Y. Construction of comparative cytogenetic maps of the Chinese hamster to mouse, rat and human. Chromosome Res 2002; 9:641-8. [PMID: 11778687 DOI: 10.1023/a:1012952223509] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We constructed comparative cytogenetic maps of the Chinese hamster to mouse, rat and human by fluorescence in-situ hybridization using 36 cDNA clones of mouse, rat, Syrian hamster, Chinese hamster and human functional genes. In this study, 30 out of the 36 genes were newly mapped to Chinese hamster chromosomes. The chromosomal homology of the Chinese hamster was identified and arranged in 19, 19 and 18 segments of conserved synteny in mouse, rat and human, respectively. Additionally, two of the 19 segments homologous to mouse chromosomes were initially identified in this study.
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Affiliation(s)
- A Kuroiwa
- Division of Bioscience, Graduate School of Environmental Earth Science, Hokkaido University, Sapporo, Japan
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