Transcriptional regulator which functions as a general RNA polymerase II transcription inhibitor ( ). Core component of the 7SK RNP complex: in cooperation with 7SK snRNA sequesters P-TEFb in a large inactive 7SK snRNP complex preventing RNA polymerase II phosphorylation and subsequent transcriptional elongation ( , ). May also regulate NF-kappa-B, ESR1, NR3C1 and CIITA-dependent transcriptional activity ( ). Plays a role in the regulation of DNA virus-mediated innate immune response by assembling into the HDP-RNP complex, a complex that serves as a platform for IRF3 phosphorylation and subsequent innate immune response activation through the cGAS-STING pathway .
Subcellular locations: Nucleus, Cytoplasm
Binds alpha-importin and is mostly nuclear .
Ubiquitously expressed with higher expression in placenta. HEXIM1 and HEXIM2 are differentially expressed. Expressed in endocrine tissues.