Nanoscale dynamics of centromere nucleosomes and the critical roles of CENP-A.
Nucleic Acids Res
; 46(1): 94-103, 2018 01 09.
Article
em En
| MEDLINE
| ID: mdl-29040671
ABSTRACT
In the absence of a functioning centromere, chromosome segregation becomes aberrant, leading to an increased rate of aneuploidy. The highly specific recognition of centromeres by kinetochores suggests that specific structural characteristics define this region, however, the structural details and mechanism underlying this recognition remains a matter of intense investigation. To address this, high-speed atomic force microscopy was used for direct visualization of the spontaneous dynamics of CENP-A nucleosomes at the sub-second time scale. We report that CENP-A nucleosomes change conformation spontaneously and reversibly, utilizing two major pathways unwrapping, and looping of the DNA; enabling core transfer between neighboring DNA substrates. Along with these nucleosome dynamics we observed that CENP-A stabilizes the histone core against dissociating to histone subunits upon unwrapping DNA, unique from H3 cores which are only capable of such plasticity in the presence of remodeling factors. These findings have implications for the dynamics and integrity of nucleosomes at the centromere.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Nucleossomos
/
Centrômero
/
Cinetocoros
/
Proteína Centromérica A
Limite:
Humans
Idioma:
En
Ano de publicação:
2018
Tipo de documento:
Article