BRG1, a SWI/SNF chromatin remodeling enzyme ATPase, is required for maintenance of nuclear shape and integrity.
We recently reported that reducing the levels of BRG1, the catalytic subunit of mammalian SWI/SNF chromatin remodeling enzymes, induces alterations in nuclear shape in a breast epithelial cell line. Immunostaining the BRG1 knockdown cells with nuclear lamina antibodies revealed a significantly increased frequency of grooves, or invaginations, in the nuclei. Disruption of each of the major cytoplasmic filament systems (actin, tubulin and cytokeratins) had no impact on the BRG1-dependent changes in nuclear shape, indicating that the observed changes in nuclear morphology are unlikely to be a result of alterations in the integrity of the nuclear-cytoplamic contacts in the cell. We propose that the BRG1-dependent nuclear shape changes reflect a role for the chromatin remodeling enzyme in maintaining the structural integrity of the nucleus via global regulation of chromatin structure and dynamics within the nucleus.
Department of Cell and Developmental Biology; University of Massachusetts Medical School; Worcester, MA USA.
Anthony N
AN
Imbalzano
Karen M
KM
Imbalzano
Jeffrey A
JA
Nickerson
BRG1; SWI/SNF; breast epithelia; chromatin; chromatin remodeling; lamina; nuclear shape