| Structural highlights
Function
H2B2E_HUMAN Core component of nucleosome. Nucleosomes wrap and compact DNA into chromatin, limiting DNA accessibility to the cellular machineries which require DNA as a template. Histones thereby play a central role in transcription regulation, DNA repair, DNA replication and chromosomal stability. DNA accessibility is regulated via a complex set of post-translational modifications of histones, also called histone code, and nucleosome remodeling.[1] [2] [3] Has broad antibacterial activity. May contribute to the formation of the functional antimicrobial barrier of the colonic epithelium, and to the bactericidal activity of amniotic fluid.[4] [5] [6]
Publication Abstract from PubMed
Pioneer transcription factors are essential for cell fate changes by targeting closed chromatin. OCT4 is a crucial pioneer factor that can induce cell reprogramming. However, the structural basis of how pioneer factors recognize the in vivo nucleosomal DNA targets is unknown. Here, we determine the high-resolution structures of the nucleosome containing human LIN28B DNA and its complexes with the OCT4 DNA binding region. Three OCT4s bind the pre-positioned nucleosome by recognizing non-canonical DNA sequences. Two use their POUS domains while the other uses the POUS-loop-POUHD region; POUHD serves as a wedge to unwrap approximately 25 base pair DNA. Our analysis of previous genomic data and determination of the ESRRB-nucleosome-OCT4 structure confirmed the generality of these structural features. Moreover, biochemical studies suggest that multiple OCT4s cooperatively open the H1-condensed nucleosome array containing the LIN28B nucleosome. Thus, our study suggests a mechanism of how OCT4 can target the nucleosome and open closed chromatin.
Structural mechanism of LIN28B nucleosome targeting by OCT4.,Guan R, Lian T, Zhou BR, Wheeler D, Bai Y Mol Cell. 2023 Jun 15;83(12):1970-1982.e6. doi: 10.1016/j.molcel.2023.05.030. PMID:37327775[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Kim HS, Cho JH, Park HW, Yoon H, Kim MS, Kim SC. Endotoxin-neutralizing antimicrobial proteins of the human placenta. J Immunol. 2002 Mar 1;168(5):2356-64. PMID:11859126
- ↑ Tollin M, Bergman P, Svenberg T, Jornvall H, Gudmundsson GH, Agerberth B. Antimicrobial peptides in the first line defence of human colon mucosa. Peptides. 2003 Apr;24(4):523-30. PMID:12860195
- ↑ Howell SJ, Wilk D, Yadav SP, Bevins CL. Antimicrobial polypeptides of the human colonic epithelium. Peptides. 2003 Nov;24(11):1763-70. PMID:15019208 doi:10.1016/j.peptides.2003.07.028
- ↑ Kim HS, Cho JH, Park HW, Yoon H, Kim MS, Kim SC. Endotoxin-neutralizing antimicrobial proteins of the human placenta. J Immunol. 2002 Mar 1;168(5):2356-64. PMID:11859126
- ↑ Tollin M, Bergman P, Svenberg T, Jornvall H, Gudmundsson GH, Agerberth B. Antimicrobial peptides in the first line defence of human colon mucosa. Peptides. 2003 Apr;24(4):523-30. PMID:12860195
- ↑ Howell SJ, Wilk D, Yadav SP, Bevins CL. Antimicrobial polypeptides of the human colonic epithelium. Peptides. 2003 Nov;24(11):1763-70. PMID:15019208 doi:10.1016/j.peptides.2003.07.028
- ↑ Guan R, Lian T, Zhou BR, Wheeler D, Bai Y. Structural mechanism of LIN28B nucleosome targeting by OCT4. Mol Cell. 2023 Jun 15;83(12):1970-1982.e6. PMID:37327775 doi:10.1016/j.molcel.2023.05.030
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