转录的启动部分受称为预启动复合物的大型蛋白质装配的控制。 这种预启动复合体的一个组成部分是一个称为Mediator的1.2 MDa蛋白聚集体。 该介体组分与包含该基因编码的蛋白质，介体复合物亚基12（MED12）以及MED13，CDK8激酶和细胞周期蛋白C的CDK8亚复合体结合。 和重新激发率。 MED12蛋白对于激活CDK8激酶至关重要。 该基因的缺陷会导致X连锁的Opitz-Kaveggia综合征（也称为FG综合征）和Lujan-Fryns综合征。 [由RefSeq提供，2009年8月]
The initiation of transcription is controlled in part by a large protein assembly known as the preinitiation complex. A component of this preinitiation complex is a 1.2 MDa protein aggregate called Mediator. This Mediator component binds with a CDK8 subcomplex which contains the protein encoded by this gene, mediator complex subunit 12 (MED12), along with MED13, CDK8 kinase, and cyclin C. The CDK8 subcomplex modulates Mediator-polymerase II interactions and thereby regulates transcription initiation and reinitation rates. The MED12 protein is essential for activating CDK8 kinase. Defects in this gene cause X-linked Opitz-Kaveggia syndrome, also known as FG syndrome, and Lujan-Fryns syndrome. [provided by RefSeq, Aug 2009]