Cell Signaling Technology

Product Pathways - Chromatin Regulation / Epigenetics

HP1α/β (C7F11) Rabbit mAb #2623

Applications Reactivity Sensitivity MW (kDa) Isotype
W IP IHC-P IF-IC H M R Mk Endogenous 25 Rabbit IgG

Applications Key:  W=Western Blotting  IP=Immunoprecipitation  IHC-P=Immunohistochemistry (Paraffin)  IF-IC=Immunofluorescence (Immunocytochemistry)
Reactivity Key:  H=Human  M=Mouse  R=Rat  Mk=Monkey
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

HP1α/β (C7F11) Rabbit mAb detects endogenous levels of total HP1 α and HP1 β protein. The antibody does not cross-react with HP1 γ proteins.

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic peptide corresponding to the carboxy terminus of human HP1 α.

Western Blotting

Western Blotting

Western blot analysis of lysates from HeLa, NIH/3T3, C6 and COS cells using HP1 α (C7F11) Rabbit mAb.

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human lung carcinoma, showing nuclear localization using HP1 α (C7F11) Rabbit mAb.

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human breast carcinoma using HP1 α (C7F11) Rabbit mAb in the presence of control peptide (left) or HP1 alpha blocking peptide #1004 (right).


IF-IC

IF-IC

Confocal immunofluorescent analysis of HeLa cells using HP1α (C7F11) Rabbit mAb (green). Actin filaments have been labeled with Alexa Fluor® 555 phalloidin (red).

Background

Heterochromatin protein 1 (HP1) is a family of heterochromatic adaptor molecules involved in both gene silencing and higher order chromatin structure (1). All three HP1 family members (α, β, and γ) are primarily associated with centromeric heterochromatin; however, HP1β and γ also localize to euchromatic sites in the genome (2,3). HP1 proteins are approximately 25 kDa in size and contain a conserved amino-terminal chromodomain, followed by a variable hinge region and a conserved carboxy-terminal chromoshadow domain. The chromodomain facilitates binding to histone H3 tri-methylated at Lys9, a histone "mark" closely associated with centromeric heterochromatin (4,5). The variable hinge region binds both RNA and DNA in a sequence-independent manner (6). The chromoshadow domain mediates the dimerization of HP1 proteins, in addition to binding multiple proteins implicated in gene silencing and heterochromatin formation, including the SUV39H histone methyltransferase, the DNMT1 and DNMT3a DNA methyltransferases, and the p150 subunit of chromatin-assembly factor-1 (CAF1) (7-9). In addition to contributing to heterochromatin formation and propagation, HP1 and SUV39H are also found complexed with retinoblastoma (Rb) and E2F6 proteins, both of which function to repress euchromatic gene transcription in quiescent cells (10,11). HP1 proteins are subject to multiple types of post-translational modifications, including phosphorylation, acetylation, methylation, ubiquitination, and sumoylation, suggesting multiple means of regulation (12-14).

  1. Maison, C. and Almouzni, G. (2004) Nat. Rev. Mol. Cell Biol. 5, 296-304.
  2. Minc, E. et al. (2000) Cytogenet. Cell Genet. 90, 279-284.
  3. Nielsen, A.L. et al. (2001) Mol. Cell 7, 729-739.
  4. Lachner, M. et al. (2001) Nature 410, 116-120.
  5. Bannister, A.J. et al. (2001) Nature 410, 120-124.
  6. Muchardt, C. et al. (2002) EMBO Rep. 3, 975-981.
  7. Yamamoto, K. and Sonoda, M. (2003) Biochem. Biophys. Res. Commun. 301, 287-292.
  8. Fuks, F. et al. (2003) Nucleic Acids Res. 31, 2305-2312.
  9. Murzina, N. et al. (1999) Mol. Cell 4, 529-540.
  10. Nielsen, S.J. et al. (2001) Nature 412, 561-565.
  11. Ogawa, H. et al. (2002) Science 296, 1132-1136.
  12. Minc, E. et al. (1999) Chromosoma 108, 220-234.
  13. Zhao, T. et al. (2001) J. Biol. Chem. 276, 9512-9518.
  14. Lomberk, G. et al. (2006) Nat. Cell Biol. 8, 407-415.

Application References

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

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