Chromatin and IP

A number of large, multisubunit complexes have been identified by their ability to remodel chromatin. In the November 14 Sciencexpress, two reports describe an unexpected link between inositol phosphates and the activity of chromatin remodeling complexes.

Xuetong Shen and colleagues show that inositol hexakiphosphate (IP₆) can inhibit nucleosome mobilization by the NURF, ISW2 and INO80 remodeling complexes in an in vitro assay (Sciencexpress, DOI:10.1126/science.1078068, 14 November 2002). They also show that IP₄ and IP₅ stimulate the remodeling activity of the yeast SWI/SNF complex and that transcription was impaired in yeast strains lacking the enzymes required to generate these IP molecules.

In the second paper, David Steger and colleagues report that inositol polyphosphates are important for recruitment of remodeling complexes and chromatin changes at the promoter of the PHO5 phosphate-responsive gene in budding yeast (Sciencexpress, DOI:10.1126/science.1078062, 14 November 2002).