protein HEXIM1 (hexamethylene bis-acetamide-inducible protein 1, cardiac lineage protein 1, estrogen down-regulated gene 1 protein, Menage a quatre protein 1, HEXIM1, CLP1, EDG1, HIS1, MAQ1)

Function: - transcriptional regulator - functions as a general RNA polymerase 2 transcription inhibitor - in cooperation with 7SK snRNA sequesters P-TEFb in a large inactive 7SK snRNP complex preventing RNA polymerase 2 phosphorylation & subsequent transcriptional elongation - may also regulate NF-kappa-B, ESR1, NR3C1 & CIITA-dependent transcriptional activity - homooligomer & heterooligomer with HEXIM2, probably dimeric - component of the 7SK snRNP complex - interacts with the N-CoR complex through NCOR1 - interacts with ESR1 & NR3C1 - mayinteract with NF-kappa-B through RELA Structure: - coiled-coil domain mediates oligomerization - belongs to the HEXIM family Compartment: - nucleus, cytoplasm - binds alpha-importin & is mostly nuclear Expression: - ubiquitously expressed - higher expression in placenta - HEXIM1 & HEXIM2 are differentially expressed - expressed in endocrine tissues - up-regulated by HMBA (hexamethylene bisacetamide) (at protein level) - down-regulated by estrogen Pathology: - inhibits Tat activity which is required for HIV-1 transcription

General

nuclear protein phosphoprotein

Properties

SIZE: entity length = 359 aa MW = 41 kD COMPARTMENT: cell nucleus MOTIF: Ser phosphorylation site {S97} Ser phosphorylation site {S98} basic region {150-177} P-TEFb interaction {202-205} basic region {210-250} coiled coil {283-349} MOTIF: mediates interaction with CCNT1 {286-314} ESR1 inhibition {310-355}

Database Correlations

OMIM 607328 UniProt O94992

References

UniProt :accession O94992