Heat shock factor 1 counteracts epigenetic silencing of nuclear transgenes in Chlamydomonas reinhardtii.

ABSTRACT: We found previously that the Chlamydomonas HSP70A promoter counteracts transcriptional silencing of downstream promoters in a transgene setting. To elucidate the underlying mechanisms, we analyzed chromatin state and transgene expression in transformants containing HSP70A-RBCS2-ble (AR-ble) constructs harboring deletions/mutations in the A promoter. We identified histone modifications at transgenic R promoters indicative for repressive chromatin, i.e. low levels of histone H3/4 acetylation and H3-lysine 4 trimethylation and high levels of H3-lysine 9 monomethylation. Transgenic A promoters also harbor lower levels of active chromatin marks than the native A promoter, but levels were higher than those at transgenic R promoters. Strikingly, in AR promoter fusions, the chromatin state at the

SUBMITTER: Strenkert D 

PROVIDER: S-EPMC3664811 | biostudies-literature | 2013 May

REPOSITORIES: biostudies-literature