The estrogen receptor (ER) is a ligand-dependent transcription factor that has two subtypes: ERα and ERβ. ERs regulate transcription of estrogen-responsive genes through interactions with multiple intranuclear components, such as cofactors and the nuclear matrix. Live cell imaging using fluorescent protein-labeled ERs has revealed that ligand-activated ERs are highly mobile in the nucleus, with transient association with the DNA and nuclear matrix. Scaffold attachment factor B (SAFB) 1 and its paralogue, SAFB2, are nuclear matrix-binding proteins that negatively modulate ERα-mediated transcription. Expression of SAFB1 and SAFB2 reduces the mobility of ERα in the presence of ligand. This regulatory machinery is emerging as an epigenetic-like mechanism that alters transcriptional activity through control of intranuclear molecular mobility.

中文翻译：

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雌激素受体的核内移动性：对转录调控的影响。

雌激素受体（ER）是一种依赖配体的转录因子，具有两种亚型：ERα和ERβ。雌激素受体通过与多种核内成分如辅因子和核基质的相互作用来调节雌激素反应性基因的转录。使用荧光蛋白标记的ER进行的活细胞成像显示，配体激活的ER在细胞核中具有很高的移动性，与DNA和核基质具有短暂的缔合。支架附着因子B（SAFB）1及其旁系SAFB2是核基质结合蛋白，可负调节ERα介导的转录。SAFB1和SAFB2的表达降低了配体存在时ERα的迁移率。这种调节机制正在作为一种表观遗传学的机制出现，该机制通过控制核内分子迁移来改变转录活性。