Cell Signaling Technology

Product Pathways - Chromatin Regulation / Epigenetics

HEXIM1 Antibody #9064

Applications Reactivity Sensitivity MW (kDa) Source
W IP H Mk (B) (Dg) (Hr) Endogenous 60 Rabbit

Applications Key:  W=Western Blotting  IP=Immunoprecipitation
Reactivity Key:  H=Human  Mk=Monkey  B=Bovine  Dg=Dog  Hr=Horse
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

HEXIM1 Antibody recognizes endogenous levels of total HEXIM1 protein.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic peptide corresponding to residues near the amino terminus of human HEXIM1 protein. Antibodies are purified by protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts from various cell lines using HEXIM1 Antibody.

Background

Hexamethylene bis-acetamide-inducible protein 1 (HEXIM1) was originally identified in vascular smooth muscle cells as a protein that is upregulated upon treatment with the differentiating agent hexamethylene bisacetamide (1). HEXIM1 binds 7SK RNA, a highly abundant non-coding RNA, and together they act as a potent inhibitor of positive transcription elongation factor b (P-TEFb) (2,3). P-TEFb phosphorylates the C-terminal domain of the largest subunit of RNA polymerase II and is an important regulator of transcription elongation (4-8). 7SK RNA-bound HEXIM1 interacts with the cyclin T1 subunit of P-TEFb, sequestering P-TEFb in an inactive form leading to transcription inhibition (2,3). The regulation of the relative ratio of inactive to active P-TEFb in the cell by HEXIM1/7SK RNA is thought to play a critical role in regulation of a wide range of cellular gene expression programs such as estrogen and glucocorticoid receptor regulated genes (9-12).

  1. Ouchida, R. et al. (2003) Genes Cells 8, 95-107.
  2. Michels, A.A. et al. (2004) EMBO J 23, 2608-19.
  3. Yik, J.H. et al. (2003) Mol Cell 12, 971-82.
  4. Buratowski, S. (2009) Mol Cell 36, 541-6.
  5. Lenasi, T. and Barboric, M. RNA Biol 7, 145-50.
  6. Pirngruber, J. et al. (2009) Cell Cycle 8, 3636-42.
  7. Wada, T. et al. (1998) EMBO J 17, 7395-403.
  8. Yamada, T. et al. (2006) Mol Cell 21, 227-37.
  9. Peterlin, B.M. et al. (2012) Wiley Interdiscip Rev RNA 3, 92-103.
  10. Ketchart, W. et al. (2011) Oncogene 30, 3563-9.
  11. Ogba, N. et al. (2008) Cancer Res 68, 7015-24.
  12. Shimizu, N. et al. (2005) Proc Natl Acad Sci U S A 102, 8555-60.

Application References

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Companion Products

For Research Use Only. Not For Use In Diagnostic Procedures.

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