WSTF-ISWI chromatin remodeling complex targets heterochromatic replication foci.
The Williams Syndrome Transcription Factor (WSTF), the product of the WBSCR9 gene, is invariably deleted in the haploinsufficiency Williams-Beuren Syndrome. Along with the nucleosome-dependent ATPase ISWI, WSTF forms a novel chromatin remodeling complex, WICH (WSTF-ISWI chromatin remodeling complex), which is conserved in vertebrates. The WICH complex was purified to homogeneity from Xenopus egg extract and was found to contain only WSTF and ISWI. In mouse cells, WSTF interacts with the SNF2H isoform of ISWI. WSTF accumulates in pericentric heterochromatin coincident with the replication of these structures, suggesting a role for WSTF in the replication of heterochromatin. Such a role is supported by the in vitro activity of both the mouse and frog WICH complexes: they are involved in the assembly of regular spaced nucleosomal arrays. In contrast to the related ISWI-interacting protein ACF1/WCRF180, WSTF binds stably to mitotic chromosomes. As dysfunction of other chromatin remodeling factors often has severe effects on development, haploinsufficiency of WSTF may explain some of the phenotypes associated with this disease.
Bozhenok
Ludmila
L
Marie Curie Research Institute, Oxted, Surrey RH8 0TL, UK.
Wade
Paul A
PA
Varga-Weisz
Patrick
P
D000251:Adenosine Triphosphatases / Q000502:physiology*; D000818:Animals; D005260:Female; D017353:Gene Deletion; D006367:HeLa Cells; D006570:Heterochromatin / Q000502:physiology*; D006801:Humans; D046911:Macromolecular Substances; D051379:Mice; D009707:Nucleosomes / Q000502:physiology; D009865:Oocytes / Q000502:physiology; D018741:Replication Origin / Q000502:physiology*; D013234:Stem Cells / Q000502:physiology; D014157:Transcription Factors / Q000502:physiology*; D018980:Williams Syndrome / Q000235:genetics; D014981:Xenopus / Q000502:physiology; D000092468:Bromodomain Containing Proteins
D000251:Adenosine Triphosphatases; D006570:Heterochromatin; D046911:Macromolecular Substances; D009707:Nucleosomes; D014157:Transcription Factors; C116750:BAZ1B protein, human; D000092468:Bromodomain Containing Proteins; C485505:Baz1b protein, mouse; C086468:ISWI protein