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Mass Spectrometry Analysis to Identify Ubiquitylation of EYFP-tagged CENP-A (EYFP-CENP-A)
Published on: June 10, 2020
Nap1 regulates proper CENP-B binding to nucleosomes
Hiroaki Tachiwana1, Yuta Miya, Nobuaki Shono
1Laboratory of Structural Biology, Graduate School of Advanced Science and Engineering, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo 162-8480, Japan.
Nucleic Acids Research
|January 18, 2013
Summary
Human Nap1, a histone chaperone, was found to regulate CENP-B binding. Nap1 inhibits non-specific binding and promotes specific binding to CENP-B boxes, facilitating CENP-B eviction from chromosomes.
Area of Science:
- Epigenetics and Chromatin Biology
- Molecular Cell Biology
- Genetics
Background:
- CENP-B is a conserved centromeric protein crucial for centromere assembly and epigenetic regulation.
- Improper CENP-B binding can lead to harmful effects, but its eviction mechanism remains unknown.
- CENP-B binds to specific DNA sequences (CENP-B boxes) within centromeric satellite DNA.
Purpose of the Study:
- To investigate the mechanism of CENP-B eviction from chromosomes.
- To identify factors that regulate CENP-B binding to centromeric DNA.
- To explore the role of histone chaperones in CENP-B regulation.
Main Methods:
- In vitro binding assays using nucleosomes and purified proteins.
- In vivo experiments using human cells with artificial chromosomes and ectopic loci.
- Utilizing tethering assays to assess the effect of Nap1 on CENP-B binding.
Main Results:
- Human Nap1, an acidic histone chaperone, inhibits non-specific CENP-B binding to nucleosomes.
- Nap1 stimulates specific CENP-B binding to CENP-B box DNA within nucleosomes.
- Nap1 demonstrated CENP-B eviction activity in vivo, reducing CENP-B binding to human artificial chromosomes and ectopic loci.
Conclusions:
- Nap1 plays a novel role in regulating CENP-B binding and eviction.
- Nap1's activity contrasts with that of sNASP, another histone chaperone.
- This study proposes a new mechanism for controlling CENP-B localization and function through histone chaperone interaction.
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