H2A.X N-terminal acetylation is a newly identified NAA40-mediated modification that is responsive to UV irradiation
Abstract Background N-terminal acetylation (Nt-Ac), mediated by N-terminal acetyltransferases (NATs) is one of the most abundant protein modifications occurring approximately in 80% of all eukaryotic proteins. In contrast to the broad spectrum NATs, the human N-alpha-acetyltransferase 40 (NAA40) is...
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| Format: | Article |
| Language: | English |
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BMC
2025-07-01
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| Series: | Epigenetics & Chromatin |
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| Online Access: | https://doi.org/10.1186/s13072-025-00608-3 |
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| author | Ariel Klavaris Costas Koufaris Roberta Noberini Maria Kouma Christina Demetriadou Alessandro Ghiringhelli Nikolas Dietis Tiziana Bonaldi Antonis Kirmizis |
| author_facet | Ariel Klavaris Costas Koufaris Roberta Noberini Maria Kouma Christina Demetriadou Alessandro Ghiringhelli Nikolas Dietis Tiziana Bonaldi Antonis Kirmizis |
| author_sort | Ariel Klavaris |
| collection | DOAJ |
| description | Abstract Background N-terminal acetylation (Nt-Ac), mediated by N-terminal acetyltransferases (NATs) is one of the most abundant protein modifications occurring approximately in 80% of all eukaryotic proteins. In contrast to the broad spectrum NATs, the human N-alpha-acetyltransferase 40 (NAA40) is highly specific, currently known to Nt-acetylate only the two histone proteins H4 and H2A, which share an Ser(1)-Gly(2)-Arg(3)-Gly(4) N-terminal sequence. Previous work from our lab and others has highlighted the biological and clinical relevance of this NAA40-mediated modification. Results In this study, by performing in silico analysis of protein sequences combined with biochemical assays we identify the histone variants H2A.X and H2A.J and the chromatin remodeler SMARCD2 as new potential substrates of human NAA40. Subsequently, focusing on H2A.X, we show for the first time by mass spectrometry analysis that H2A.X is N-terminally acetylated (Nt-acH2A.X) within human cells. Next, we demonstrate that NAA40 specifically interacts and N-terminally acetylates histone H2A.X, in vitro and within cells. Finally, we provide evidence that H2A.X N-terminal acetylation is responsive to Ultraviolet B (UVB)-induced DNA damage and its associated enzyme NAA40 affects the survival of cells exposed to UVB irradiation. Conclusion Our findings identify H2A.X as a novel bona fide substrate of NAA40. Moreover, the responsiveness of H2A.X N-terminal acetylation to UV-induced DNA damage indicates that this is a dynamic modification with potential biological functions. |
| format | Article |
| id | doaj-art-11199ee00e5241d7bb86bb5881f1d45e |
| institution | Kabale University |
| issn | 1756-8935 |
| language | English |
| publishDate | 2025-07-01 |
| publisher | BMC |
| record_format | Article |
| series | Epigenetics & Chromatin |
| spelling | doaj-art-11199ee00e5241d7bb86bb5881f1d45e2025-08-20T03:46:15ZengBMCEpigenetics & Chromatin1756-89352025-07-0118111710.1186/s13072-025-00608-3H2A.X N-terminal acetylation is a newly identified NAA40-mediated modification that is responsive to UV irradiationAriel Klavaris0Costas Koufaris1Roberta Noberini2Maria Kouma3Christina Demetriadou4Alessandro Ghiringhelli5Nikolas Dietis6Tiziana Bonaldi7Antonis Kirmizis8Department of Biological Sciences, University of CyprusDepartment of Biological Sciences, University of CyprusDepartment of Experimental Oncology, IEO, European Institute of Oncology IRCCSDepartment of Biological Sciences, University of CyprusDepartment of Biological Sciences, University of CyprusDepartment of Experimental Oncology, IEO, European Institute of Oncology IRCCSExperimental Pharmacology Laboratory, Medical School, University of CyprusDepartment of Experimental Oncology, IEO, European Institute of Oncology IRCCSDepartment of Biological Sciences, University of CyprusAbstract Background N-terminal acetylation (Nt-Ac), mediated by N-terminal acetyltransferases (NATs) is one of the most abundant protein modifications occurring approximately in 80% of all eukaryotic proteins. In contrast to the broad spectrum NATs, the human N-alpha-acetyltransferase 40 (NAA40) is highly specific, currently known to Nt-acetylate only the two histone proteins H4 and H2A, which share an Ser(1)-Gly(2)-Arg(3)-Gly(4) N-terminal sequence. Previous work from our lab and others has highlighted the biological and clinical relevance of this NAA40-mediated modification. Results In this study, by performing in silico analysis of protein sequences combined with biochemical assays we identify the histone variants H2A.X and H2A.J and the chromatin remodeler SMARCD2 as new potential substrates of human NAA40. Subsequently, focusing on H2A.X, we show for the first time by mass spectrometry analysis that H2A.X is N-terminally acetylated (Nt-acH2A.X) within human cells. Next, we demonstrate that NAA40 specifically interacts and N-terminally acetylates histone H2A.X, in vitro and within cells. Finally, we provide evidence that H2A.X N-terminal acetylation is responsive to Ultraviolet B (UVB)-induced DNA damage and its associated enzyme NAA40 affects the survival of cells exposed to UVB irradiation. Conclusion Our findings identify H2A.X as a novel bona fide substrate of NAA40. Moreover, the responsiveness of H2A.X N-terminal acetylation to UV-induced DNA damage indicates that this is a dynamic modification with potential biological functions.https://doi.org/10.1186/s13072-025-00608-3NAA40H2A.XAcetylationChromatinEpigeneticsHistone |
| spellingShingle | Ariel Klavaris Costas Koufaris Roberta Noberini Maria Kouma Christina Demetriadou Alessandro Ghiringhelli Nikolas Dietis Tiziana Bonaldi Antonis Kirmizis H2A.X N-terminal acetylation is a newly identified NAA40-mediated modification that is responsive to UV irradiation Epigenetics & Chromatin NAA40 H2A.X Acetylation Chromatin Epigenetics Histone |
| title | H2A.X N-terminal acetylation is a newly identified NAA40-mediated modification that is responsive to UV irradiation |
| title_full | H2A.X N-terminal acetylation is a newly identified NAA40-mediated modification that is responsive to UV irradiation |
| title_fullStr | H2A.X N-terminal acetylation is a newly identified NAA40-mediated modification that is responsive to UV irradiation |
| title_full_unstemmed | H2A.X N-terminal acetylation is a newly identified NAA40-mediated modification that is responsive to UV irradiation |
| title_short | H2A.X N-terminal acetylation is a newly identified NAA40-mediated modification that is responsive to UV irradiation |
| title_sort | h2a x n terminal acetylation is a newly identified naa40 mediated modification that is responsive to uv irradiation |
| topic | NAA40 H2A.X Acetylation Chromatin Epigenetics Histone |
| url | https://doi.org/10.1186/s13072-025-00608-3 |
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