Propagation of centromeric chromatin requires exit from mitosis.
J Cell Biol
; 176(6): 795-805, 2007 Mar 12.
Article
em En
| MEDLINE
| ID: mdl-17339380
ABSTRACT
Centromeres direct chromosomal inheritance by nucleating assembly of the kinetochore, a large multiprotein complex required for microtubule attachment during mitosis. Centromere identity in humans is epigenetically determined, with no DNA sequence either necessary or sufficient. A prime candidate for the epigenetic mark is assembly into centromeric chromatin of centromere protein A (CENP-A), a histone H3 variant found only at functional centromeres. A new covalent fluorescent pulse-chase labeling approach using SNAP tagging has now been developed and is used to demonstrate that CENP-A bound to a mature centromere is quantitatively and equally partitioned to sister centromeres generated during S phase, thereby remaining stably associated through multiple cell divisions. Loading of nascent CENP-A on the megabase domains of replicated centromere DNA is shown to require passage through mitosis but not microtubule attachment. Very surprisingly, assembly and stabilization of new CENP-A-containing nucleosomes is restricted exclusively to the subsequent G1 phase, demonstrating direct coupling between progression through mitosis and assembly/maturation of the next generation of centromeres.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Autoantígenos
/
Cromatina
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Proteínas Cromossômicas não Histona
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Centrômero
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Mitose
Limite:
Humans
Idioma:
En
Ano de publicação:
2007
Tipo de documento:
Article