Related Experiment Video
Updated: Jun 2, 2025
05:35
Immunofluorescence Analysis of Endogenous and Exogenous Centromere-kinetochore Proteins
Published on: March 3, 2016
15.2K
Non-nucleosomal (CENP-A/H4)2 - DNA complexes as a possible platform for centromere organization
Ahmad Ali-Ahmad1, Mira Mors2, Manuel Carrer2
1Centre for Molecular Medicine Norway (NCMM), Nordic EMBL Partnership, Faculty of Medicine, University of Oslo, Oslo 0318, Norway.
Biorxiv : the Preprint Server for Biology
|January 13, 2025
Summary
The centromere
Area of Science:
- Cell Biology
- Epigenetics
- Structural Biology
Background:
- The centromere is epigenetically marked by CENP-A (centromere protein A), a histone H3 variant, essential for chromosome segregation.
- CENP-A nucleosomes recruit the centromere-associated network of proteins (CCAN) to form the kinetochore.
- Previous structures showed limited interaction between CENP-A and CCAN, leaving its organization mechanism unclear.
Purpose of the Study:
- To elucidate the structural basis of CENP-A nucleosome organization and its role in CCAN recruitment.
- To investigate the structure of CENP-A/H4 tetramers and di-tetramers assembled on DNA.
Main Methods:
- Cryo-electron microscopy (cryoEM) was used to determine the structure of CENP-A/H4 tetramers and di-tetramers.
- Nucleosomes were assembled on DNA in the absence of H2A/H2B histone dimers.
Main Results:
- The cryoEM structure of 2x(CENP-A/H4)2-di-tetramers assembled on DNA was determined.
- This structure reveals the organization of CENP-A/H4 tetramers and di-tetramers.
Conclusions:
- The (CENP-A/H4)2-tetramers and -di-tetramers provide a structural platform for CCAN organization.
- This finding offers insights into the assembly and function of centromeres during cell division.
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