The zinc-finger protein CLAMP promotes gypsy chromatin insulator function in Drosophila.

Autor: Bag, Indira, Dale, Ryan K., Palmer, Cameron, Lei, Elissa P.
Předmět:
Zdroj: Journal of Cell Science; Feb2019, Vol. 132 Issue 3, p1-59, 59p
Abstrakt: Chromatin insulators are DNA-protein complexes that establish independent higher order DNA domains to influence transcription. Insulators are functionally defined by two different properties: they can block communication between an enhancer and a promoter and also act as a barrier between heterochromatin and euchromatin. In Drosophila, the gypsy insulator complex contains three core components; Su(Hw), CP190 and Mod(mdg4)67.2. Here, we identify a novel role for Chromatin-linked adaptor for MSL proteins (CLAMP) in promoting gypsy chromatin insulator function. When clamp is depleted, gypsy-dependent enhancer blocking and barrier activities are strongly reduced. CLAMP associates physically with the core gypsy insulator complex, and ChIP-seq analysis reveals extensive overlap particularly with promoter-bound CP190 on chromatin. Depletion of CLAMP disrupts CP190 binding at a minority of shared sites, but depletion of CP190 results in extensive loss of CLAMP chromatin association. Finally, reduction of CLAMP disrupts CP190 localization within the nucleus. Our results support a positive functional relationship between CLAMP and CP190 to promote gypsy chromatin insulator activity. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index