Isolation of a 40-kDa Huntingtin-associated Protein

Matthew F. Peters, Christopher A. Ross

Research output: Contribution to journalArticlepeer-review

47 Scopus citations


Huntington's disease is caused by an expanded CAG trinucleotide repeat coding for a polyglutamine stretch within the huntingtin protein. Currently, the function of normal huntingtin and the mechanism by which expanded huntingtin causes selective neurotoxicity remain unknown. Clues may come from the identification of huntingtin-associated proteins (HAPs). Here, we show that huntingtin copurifies with a single novel 40-kDa protein termed HAP40. HAP40 is encoded by the open reading frame factor VIII-associated gene A (F8A) located within intron 22 of the factor VIII gene. In transfected cell extracts, HAP40 coimmunoprecipitates with full-length huntingtin but not with an N-terminal huntingtin fragment. Recombinant HAP40 is cytoplasmic in the presence of huntingtin but is actively targeted to the nucleus in the absence of huntingtin. These data indicate that HAP40 is likely to contribute to the function of normal huntingtin and is a candidate for involvement in the aberrant nuclear localization of mutant huntingtin found in degenerating neurons in Huntington's disease.

Original languageEnglish (US)
Pages (from-to)3188-3194
Number of pages7
JournalJournal of Biological Chemistry
Issue number5
StatePublished - Feb 2 2001

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


Dive into the research topics of 'Isolation of a 40-kDa Huntingtin-associated Protein'. Together they form a unique fingerprint.

Cite this