Mitotic inactivation of a human SWI/SNF chromatin remodeling complex
AUTOR(ES)
Sif, Saïd
FONTE
Cold Spring Harbor Laboratory Press
RESUMO
During mitosis, chromatin is condensed into mitotic chromosomes and transcription is inhibited, processes that might be opposed by the chromatin remodeling activity of the SWI/SNF complexes. Brg1 and hBrm, which are components of human SWI/SNF (hSWI/SNF) complexes, were recently shown to be phosphorylated during mitosis. This suggested that phosphorylation might be used as a switch to modulate SWI/SNF activity. Using an epitope-tag strategy, we have purified hSWI/SNF complexes at different stages of the cell cycle, and found that hSWI/SNF was inactive in cells blocked in G2–M. Mitotic hSWI/SNF contained Brg1 but not hBrm, and was phosphorylated on at least two subunits, hSWI3 and Brg1. In vitro, active hSWI/SNF from asynchronous cells can be phosphorylated and inactivated by ERK1, and reactivated by dephosphorylation. hSWI/SNF isolated as cells traversed mitosis regained activity when its subunits were dephosphorylated either in vitro or in vivo. We propose that this transitional inactivation and reactivation of hSWI/SNF is required for formation of a repressed chromatin structure during mitosis and reformation of an active chromatin structure as cells leave mitosis.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=317164Documentos Relacionados
- Recruitment of the SWI/SNF chromatin remodeling complex by transcriptional activators
- A Specificity and Targeting Subunit of a Human SWI/SNF Family-Related Chromatin-Remodeling Complex
- Modulation of Nucleotide Excision Repair by Mammalian SWI/SNF Chromatin-remodeling Complex*
- Effect of Damage Type on Stimulation of Human Excision Nuclease by SWI/SNF Chromatin Remodeling Factor
- Novel SWI/SNF Chromatin-Remodeling Complexes Contain a Mixed-Lineage Leukemia Chromosomal Translocation Partner