Mouse anti-Human/Mouse/Rat sapiens (Human) HEXIM1 Monoclonal Antibody

Function

Transcriptional regulator which functions as a general RNA polymerase II transcription inhibitor (PubMed:14580347, PubMed:15201869, PubMed:15713661). 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 (PubMed:12832472, PubMed:14580347, PubMed:15201869, PubMed:15713661). May also regulate NF-kappa-B, ESR1, NR3C1 and CIITA-dependent transcriptional activity (PubMed:15940264, PubMed:15941832, PubMed:17088550). 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 (PubMed:28712728)

Subcellular Location

Nucleus; Cytoplasm

Tissue Specificity

Ubiquitously expressed with higher expression in placenta. HEXIM1 and HEXIM2 are differentially expressed. Expressed in endocrine tissues

Subunit

Homooligomer and heterooligomer with HEXIM2; probably dimeric (PubMed:15713661, PubMed:15965233, PubMed:16377779). Core component of the 7SK RNP complex, at least composed of 7SK RNA, LARP7, MEPCE, HEXIM1 (or HEXIM2) and P-TEFb (composed of CDK9 and CCNT1/cyclin-T1) (PubMed:12832472, PubMed:15169877, PubMed:15201869, PubMed:15713661, PubMed:15855166, PubMed:16362050, PubMed:16377779, PubMed:17643375, PubMed:17724342, PubMed:30134174). Interacts with the N-CoR complex through NCOR1 (PubMed:17452463). Interacts with ESR1 and NR3C1 (PubMed:15940264, PubMed:15941832). May interact with NF-kappa-B through RELA (PubMed:12581153). Interacts with CCNT2; mediates formation of a tripartite complex with KPNA2 (PubMed:19883659). Part of the HDP-RNP complex composed of at least HEXIM1, PRKDC, XRCC5, XRCC6, paraspeckle proteins (SFPQ, NONO, PSPC1, RBM14, and MATR3) and NEAT1 non-coding RNA (PubMed:28712728)

• Kusuhara M. et al. Cloning of hexamethylene-bis-acetamide-inducible transcript, HEXIM1, in human vascular smooth muscle cells. — Biomed. Res. (1999)
• Ota T. et al. Complete sequencing and characterization of 21,243 full-length human cDNAs. — Nat. Genet. (2004)
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). — Genome Res. (2004)
• Wittmann B.M. et al. Identification of a novel inhibitor of breast cell growth that is down-regulated by estrogens and decreased in breast tumors. — Cancer Res. (2003)
• Ouchida R. et al. Suppression of NF-kappaB-dependent gene expression by a hexamethylene bisacetamide-inducible protein HEXIM1 in human vascular smooth muscle cells. — Genes Cells (2003)
• Yik J.H.N. et al. Inhibition of P-TEFb (CDK9/Cyclin T) kinase and RNA polymerase II transcription by the coordinated actions of HEXIM1 and 7SK snRNA. — Mol. Cell (2003)
• Michels A.A. et al. MAQ1 and 7SK RNA interact with CDK9/cyclin T complexes in a transcription-dependent manner. — Mol. Cell. Biol. (2003)
• Michels A.A. et al. Binding of the 7SK snRNA turns the HEXIM1 protein into a P-TEFb (CDK9/cyclin T) inhibitor. — EMBO J. (2004)