Preparing your results

Our searching services are busy right now. Your search will reload in five seconds.

X
Forgot Password

If you have forgotten your password you can enter your email here and get a temporary password sent to your email.

Huntingtin facilitates polycomb repressive complex 2.

Human molecular genetics | Feb 15, 2010

http://www.ncbi.nlm.nih.gov/pubmed/19933700

Huntington's disease (HD) is caused by expansion of the polymorphic polyglutamine segment in the huntingtin protein. Full-length huntingtin is thought to be a predominant HEAT repeat alpha-solenoid, implying a role as a facilitator of macromolecular complexes. Here we have investigated huntingtin's domain structure and potential intersection with epigenetic silencer polycomb repressive complex 2 (PRC2), suggested by shared embryonic deficiency phenotypes. Analysis of a set of full-length recombinant huntingtins, with different polyglutamine regions, demonstrated dramatic conformational flexibility, with an accessible hinge separating two large alpha-helical domains. Moreover, embryos lacking huntingtin exhibited impaired PRC2 regulation of Hox gene expression, trophoblast giant cell differentiation, paternal X chromosome inactivation and histone H3K27 tri-methylation, while full-length endogenous nuclear huntingtin in wild-type embryoid bodies (EBs) was associated with PRC2 subunits and was detected with trimethylated histone H3K27 at Hoxb9. Supporting a direct stimulatory role, full-length recombinant huntingtin significantly increased the histone H3K27 tri-methylase activity of reconstituted PRC2 in vitro, and structure-function analysis demonstrated that the polyglutamine region augmented full-length huntingtin PRC2 stimulation, both in Hdh(Q111) EBs and in vitro, with reconstituted PRC2. Knowledge of full-length huntingtin's alpha-helical organization and role as a facilitator of the multi-subunit PRC2 complex provides a novel starting point for studying PRC2 regulation, implicates this chromatin repressive complex in a neurodegenerative disorder and sets the stage for further study of huntingtin's molecular function and the impact of its modulatory polyglutamine region.

Pubmed ID: 19933700 RIS Download

Mesh terms: Animals | Disease Models, Animal | Female | Histones | Humans | Huntington Disease | Male | Mice | Mice, Knockout | Molecular Sequence Data | Nerve Tissue Proteins | Nuclear Proteins | Polycomb-Group Proteins | Protein Binding | Repressor Proteins | Sequence Homology, Amino Acid

Research resources used in this publication

None found

Research tools detected in this publication

Data used in this publication

None found

Associated grants

  • Agency: NIGMS NIH HHS, Id: GM62580
  • Agency: NINDS NIH HHS, Id: R01 NS049206

Publication data is provided by the National Library of Medicine ® and PubMed ®. Data is retrieved from PubMed ® on a weekly schedule. For terms and conditions see the National Library of Medicine Terms and Conditions.