Evidence map›Paper›PMID 40140990›Full record

ArticleEpigenetics & chromatin2025

Function of HP1BP3 as a linker histone is regulated by linker histone chaperones, NPM1 and TAF-I.

Miharu Hisaoka, Tetsuro Komatsu, Takuma Hashimoto, Jianhuang Lin, Yasuyuki Ohkawa, Mitsuru Okuwaki

Abstract read
In one paragraph

Article in Epigenetics & chromatin, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

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1citing papers in PubMed
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1 · What the graph read from it

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3 · Its place in the literature

Who cites it

1 citing paper in PubMed.

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4 · The record

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5 · Who and what money

Authors and funding

6 authors.

Miharu HisaokaGraduate School of Comprehensive Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305- 8575, Japan.
Tetsuro KomatsuLaboratory of Epigenetics and Metabolism, Institute for Molecular and Cellular Regulation, Gunma University, Gunma, 371-8512, Japan.
Takuma HashimotoLaboratory of Biochemistry, School of Pharmacy and Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-Ku, Tokyo, 108-8641, Japan.
Jianhuang LinGraduate School of Comprehensive Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, 305- 8575, Japan.
Yasuyuki OhkawaDivision of Transcriptomics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi, 812-0054, Fukuoka, Japan.
Mitsuru OkuwakiLaboratory of Biochemistry, School of Pharmacy and Graduate School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-Ku, Tokyo, 108-8641, Japan. okuwakim@pharm.kitasato-u.ac.jp.

Funding

Gunma University 22010Japan Society for the Promotion of Science 17K07300Japan Society for the Promotion of Science,Japan 23K07983Japan Society for the Promotion of Science,Japan 26440021Ministry of Education, Culture, Sports, Science and Technology,Japan JPMXP1323015486
6 · The paper itself

Abstract

backgroundLinker histones constitute a class of proteins that are responsible for the formation of higher-order chromatin structures. Core histones are integral components of nucleosome core particles (NCPs), whereas linker histones bind to linker DNA between NCPs. Heterochromatin protein 1 binding protein 3 (HP1BP3) displays sequence similarity to linker histones, with the exception of the presence of three globular domains in its central region. However, the function of HP1BP3 as a linker histone has not been analyzed previously. The present study aimed to elucidate the function of full-length HP1BP3 as a linker histone variant.

resultsThe results of biochemical analyses demonstrate that HP1BP3 efficiently binds to NCPs with similar efficiency as linker histones, thereby forming a chromatosome. Notwithstanding the presence of three globular domains, the results suggest that a single HP1BP3 binds to a single NCP under our biochemical assay condition. Moreover, our findings revealed that the NCP binding activity of HP1BP3 is regulated by linker histone chaperones, nucleophosmin (NPM1) and template activating factor-I (TAF-I). The globular domains and the C-terminal disordered region of HP1BP3 are responsible for binding to histone chaperones. Chromatin immunoprecipitation-sequence analyses demonstrated that HP1BP3 exhibited weak preferences for the genomic loci where histone H3 active modification marks were enriched, whereas a linker histone variant, H1.2, showed weak preferences for the genomic loci where histone H3 inactive modification marks were enriched. It is noteworthy that the preferential binding tendencies of HP1BP3 and H1.2 to active and inactive genomic loci, respectively, are diminished upon the knockdown of either NPM1 or TAF-I.

conclusionsOur findings indicate that HP1BP3 functions as a linker histone variant and that the chromatin binding preference of linker histones, including HP1BP3, is regulated by linker histone chaperones.

Indexed as

Chromosomal Proteins, Non-HistoneHistone ChaperonesHistonesNuclear ProteinsTATA-Binding Protein Associated FactorsHeLa CellsHistone AcetyltransferasesHumansNucleophosminNucleosomesProtein BindingProtein DomainsTranscription Factor TFIIDChromosomal Proteins, Non-HistoneHistone AcetyltransferasesHistone ChaperonesHistonesNPM1 protein, humanNuclear ProteinsNucleophosminNucleosomesTATA-binding protein associated factor 250 kDaTATA-Binding Protein Associated FactorsTranscription Factor TFIID

Identifiers

PMID40140990
PMCPMC11948679

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.