The histone H3/H4 chaperone CHAF1B prevents the mislocalization of CENP-A for chromosomal stability.
J Cell Sci
; 136(10)2023 05 15.
Article
in En
| MEDLINE
| ID: mdl-37129573
ABSTRACT
Restricting the localization of the evolutionarily conserved centromeric histone H3 variant CENP-A to centromeres prevents chromosomal instability (CIN). The mislocalization of CENP-A to non-centromeric regions contributes to CIN in yeasts, flies and human cells. Even though overexpression and mislocalization of CENP-A have been reported in cancers, the mechanisms responsible for its mislocalization remain poorly understood. Here, we used an imaging-based high-throughput RNAi screen to identify factors that prevent mislocalization of overexpressed YFP-tagged CENP-A (YFP-CENP-A) in HeLa cells. Among the top five candidates in the screen - the depletion of which showed increased nuclear YFP-CENP-A fluorescence - were the histone chaperones CHAF1B (or p60) and CHAF1A (or p150). Follow-up validation and characterization experiments showed that CHAF1B-depleted cells exhibited CENP-A mislocalization, CIN phenotypes and increased enrichment of CENP-A in chromatin fractions. The depletion of DAXX, a histone H3.3 chaperone, suppressed CENP-A mislocalization and CIN in CHAF1B-depleted cells. We propose that in CHAF1B-depleted cells, DAXX promotes mislocalization of the overexpressed CENP-A to non-centromeric regions, resulting in CIN. In summary, we identified regulators of CENP-A localization and defined a role for CHAF1B in preventing DAXX-dependent CENP-A mislocalization and CIN.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Chromosomal Proteins, Non-Histone
/
Histones
Type of study:
Prognostic_studies
Limits:
Humans
Language:
En
Journal:
J Cell Sci
Year:
2023
Document type:
Article
Affiliation country:
United States