Revision 1

#2600Store at -20C

Cell Signaling Technology

Orders: 877-616-CELL (2355) [email protected]

Support: 877-678-TECH (8324)

Web: [email protected] cellsignal.com

3 Trask LaneDanversMassachusetts01923USA
For Research Use Only. Not for Use in Diagnostic Procedures.
Applications:

WB, IP, IF-IC

REACTIVITY:

H M R Mk

SENSITIVITY:

Endogenous

MW (kDa):

22

SOURCE:

Rabbit

UniProt ID:

#Q13185

Entrez-Gene Id:

11335

Product Information

Product Usage Information

Application Dilution
Western Blotting 1:1000
Immunoprecipitation 1:25
Immunofluorescence (Immunocytochemistry) 1:200

Storage

Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA and 50% glycerol. Store at –20°C. Do not aliquot the antibody.

Specificity / Sensitivity

Phospho-HP1γ (Ser83) Antibody detects endogenous levels of HP1γ protein only when phosphorylated on Ser83 (also referred to as Ser93 of the unprocessed form of HP1γ). This antibody does not cross-react with HP1α or HP1β proteins.

Species Reactivity:

Human, Mouse, Rat, Monkey

Species predicted to react based on 100% sequence homology

D. melanogaster, Bovine, Horse

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide corresponding to amino acids surrounding Ser83 of human HP1γ. Antibodies are purified by affinity chromatography.

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).
HP1γ is phosphorylated on Ser83 by protein kinase A (PKA) in vitro, and activation of PKA by forskolin and IBMX treatment leads to increased phosphorylation in vivo (14). Phosphorylation of HP1γ on Ser83 also increases during mitosis as demonstrated by the Phospho-HP1γ (Ser83) Antibody, which shows increased immunofluorescent staining in untreated mitotic cells and increased Western blot signal in lysates from cells arrested in mitosis by treatment with paclitaxel. Phosphorylation of Ser83 only occurs on a subpopulation of HP1γ found associated with euchromatin, specifically HP1γ bound to coding regions of active genes (14). 
This phosphorylation impairs the ability of HP1γ to silence transcription and may be a marker for transcription elongation (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.

Species Reactivity

Species reactivity is determined by testing in at least one approved application (e.g., western blot).

Western Blot Buffer

IMPORTANT: For western blots, incubate membrane with diluted primary antibody in 5% w/v BSA, 1X TBS, 0.1% Tween® 20 at 4°C with gentle shaking, overnight.

Applications Key

WB: Western Blotting IP: Immunoprecipitation IF-IC: Immunofluorescence (Immunocytochemistry)

Cross-Reactivity Key

H: human M: mouse R: rat Hm: hamster Mk: monkey Vir: virus Mi: mink C: chicken Dm: D. melanogaster X: Xenopus Z: zebrafish B: bovine Dg: dog Pg: pig Sc: S. cerevisiae Ce: C. elegans Hr: horse GP: Guinea Pig Rab: rabbit All: all species expected

Trademarks and Patents

Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc.
Alexa Fluor is a registered trademark of Life Technologies Corporation.
All other trademarks are the property of their respective owners. Visit cellsignal.com/trademarks for more information.

Limited Uses

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Products are labeled with For Research Use Only or a similar labeling statement and have not been approved, cleared, or licensed by the FDA or other regulatory foreign or domestic entity, for any purpose. Customer shall not use any Product for any diagnostic or therapeutic purpose, or otherwise in any manner that conflicts with its labeling statement. Products sold or licensed by CST are provided for Customer as the end-user and solely for research and development uses. Any use of Product for diagnostic, prophylactic or therapeutic purposes, or any purchase of Product for resale (alone or as a component) or other commercial purpose, requires a separate license from CST. Customer shall (a) not sell, license, loan, donate or otherwise transfer or make available any Product to any third party, whether alone or in combination with other materials, or use the Products to manufacture any commercial products, (b) not copy, modify, reverse engineer, decompile, disassemble or otherwise attempt to discover the underlying structure or technology of the Products, or use the Products for the purpose of developing any products or services that would compete with CST products or services, (c) not alter or remove from the Products any trademarks, trade names, logos, patent or copyright notices or markings, (d) use the Products solely in accordance with CST Product Terms of Sale and any applicable documentation, and (e) comply with any license, terms of service or similar agreement with respect to any third party products or services used by Customer in connection with the Products.

Revision 1
#2600

Phospho-HP1γ (Ser83) Antibody

Western Blotting Image 1: Phospho-HP1γ (Ser83) Antibody Expand Image
Western blot analysis of whole cell extracts from HeLa cells, untreated (lanes 1 and 4), treated for 1 h with Forskolin (30 μM) and IBMX (0.5 mM) (lanes 2 and 3), or treated for 16 h with paclitaxel (500 nM) (lanes 5 and 6), using Phospho-HP1γ (Ser83) Antibody (upper panel) or HP1γ Antibody #2619 (lower panel).
No image available
Immunofluorescence Image 1: Phospho-HP1γ (Ser83) Antibody Expand Image
Confocal immunofluorescent analysis of HeLa cells, untreated (left), forskolin- and IBMX-treated (center) or λ phosphatase-treated (right), using Phospho-HP1γ (Ser83) Antibody (green). Actin filaments have been labeled with Alexa Fluor® 555 phalloidin (red).