» Articles » PMID: 39848706

High-resolution Analysis of Human Centromeric Chromatin

Overview
Date 2025 Jan 23
PMID 39848706
Authors
Affiliations
Soon will be listed here.
Abstract

Centromeres are marked by the centromere-specific histone H3 variant CENP-A/CENH3. Throughout the cell cycle, the constitutive centromere-associated network is bound to CENP-A chromatin, but how this protein network modifies CENP-A nucleosome conformations in vivo is unknown. Here, we purify endogenous centromeric chromatin associated with the CENP-C complex across the cell cycle and analyze the structures by single-molecule imaging and biochemical assays. CENP-C complex-bound chromatin was refractory to MNase digestion. The CENP-C complex increased in height throughout the cell cycle culminating in mitosis, and the smaller CENP-C complex corresponds to the dimensions of in vitro reconstituted constitutive centromere-associated network. In addition, we found two distinct CENP-A nucleosomal configurations; the taller variant was associated with the CENP-C complex. Finally, CENP-A mutants partially corrected CENP-C overexpression-induced centromeric transcription and mitotic defects. In all, our data support a working model in which CENP-C is critical in regulating centromere homeostasis by supporting a unique higher order structure of centromeric chromatin and altering the accessibility of the centromeric chromatin fiber for transcriptional machinery.

References
1.
Cheeseman I . The kinetochore. Cold Spring Harb Perspect Biol. 2014; 6(7):a015826. PMC: 4067989. DOI: 10.1101/cshperspect.a015826. View

2.
Pesenti M, Prumbaum D, Auckland P, Smith C, Faesen A, Petrovic A . Reconstitution of a 26-Subunit Human Kinetochore Reveals Cooperative Microtubule Binding by CENP-OPQUR and NDC80. Mol Cell. 2018; 71(6):923-939.e10. PMC: 6162344. DOI: 10.1016/j.molcel.2018.07.038. View

3.
Yoda K, Nakamura T, Masumoto H, Suzuki N, Kitagawa K, Nakano M . Centromere protein B of African green monkey cells: gene structure, cellular expression, and centromeric localization. Mol Cell Biol. 1996; 16(9):5169-77. PMC: 231517. DOI: 10.1128/MCB.16.9.5169. View

4.
Hasson D, Panchenko T, Salimian K, Salman M, Sekulic N, Alonso A . The octamer is the major form of CENP-A nucleosomes at human centromeres. Nat Struct Mol Biol. 2013; 20(6):687-95. PMC: 3760417. DOI: 10.1038/nsmb.2562. View

5.
Guo L, Allu P, Zandarashvili L, McKinley K, Sekulic N, Dawicki-McKenna J . Centromeres are maintained by fastening CENP-A to DNA and directing an arginine anchor-dependent nucleosome transition. Nat Commun. 2017; 8:15775. PMC: 5472775. DOI: 10.1038/ncomms15775. View