The hbrm and BRG-1 proteins, components of the human SNF/SWI complex, are phosphorylated and excluded from the condensed chromosomes during mitosis.

AUTOR(ES)

Muchardt, C

RESUMO

In yeast, the SNF/SWI complex is believed to regulate transcription by locally altering the chromatin structure. At the present time, three human homologues of yeast SNF/SWI proteins have been characterized: hbrm and BRG-1, homologues of SNF2/SWI2, and hSNF5, a homologue of SNF5. We show here that, during mitosis, hbrm and BRG-1 are phosphorylated and excluded from the condensed chromosomes. In this phase of the cell cycle, the level of hbrm protein is also strongly reduced, whereas the level of BRG-1 remains constant. The mitotic phosphorylation of hbrm and BRG-1 is found not to disrupt the association of these proteins with hSNF5 but correlates with a decreased affinity for the nuclear structure in early M phase. We suggest that chromosomal exclusion of the human SNF/SWI complex at the G2-M transition could be part of the mechanism leading to transcriptional arrest during mitosis.

Documentos Relacionados

• Essential Functional Interactions of Saga, a Saccharomyces Cerevisiae Complex of Spt, Ada, and Gcn5 Proteins, with the Snf/Swi and Srb/Mediator Complexes
• Cyclin E Associates with BAF155 and BRG1, Components of the Mammalian SWI-SNF Complex, and Alters the Ability of BRG1 To Induce Growth Arrest
• Whole-genome expression analysis of snf/swi mutants of Saccharomyces cerevisiae
• Epstein-Barr virus nuclear protein 2 (EBNA2) binds to a component of the human SNF-SWI complex, hSNF5/Ini1.
• The Drosophila snr1 and brm proteins are related to yeast SWI/SNF proteins and are components of a large protein complex.