Interaction of Huntingtin-associated protein with dynactin P150(Glued)

• Type of Material: Article
• Authors: Shihua Li, Emory University; Claire-Anne Gutekunst, Emory University; Steven M Hersch, Emory University; Xiao-Jiang Li, Emory University
• Language: English
• Date: 1998-02-15
• Publisher: Society for Neuroscience
• Publication Version: Final Published Version
• Copyright Statement: © 1998 Society for Neuroscience
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1523/jneurosci.18-04-01261.1998
• Title of Journal or Parent Work: Journal of Neuroscience
• Volume: 18
• Issue: 4
• Start Page: 1261
• End Page: 1269
• Grant/Funding Information: This work was supported by Emory University Research Committee, the Wills Foundation, the Hereditary Disease Foundation (X.-J.L.), the United States Public Health Service (Grant NS01624 to S.M.H.), and the Markey Center for Neurological Sciences (C.-A.G.)
• Keywords: GENE; targeting; IDENTIFICATION; EXPANSION; intracellular transport; microtubule; BRAIN; Life Sciences & Biomedicine; NEURODEGENERATIVE DISEASES; huntingtin; CAG REPEAT; dynactin; FAST AXONAL-TRANSPORT; Science & Technology; CYTOPLASMIC DYNEIN; COMPLEX; Neurosciences & Neurology; Huntington's disease; LOCALIZATION; Neurosciences
• Research Categories: Health Sciences, Medicine and Surgery; Biology, Genetics; Biology, Neuroscience

Abstract

Huntingtin is the protein product of the gene for Huntington's disease (HD) and carries a polyglutamine repeat that is expanded in HD (>36 units). Huntingtin-associated protein (HAP1) is a neuronal protein and binds to huntingtin in association with the polyglutamine repeat. Like huntingtin, HAP1 has been found to be a cytoplasmic protein associated with membranous organelles, suggesting the existence of a protein complex including HAP1, huntingtin, and other proteins. Using the yeast two-hybrid system, we found that HAP1 also binds to dynactin P150(Glued) (P150), an accessory protein for cytoplasmic dynein that participates in microtubule-dependent retrograde transport of membranous organelles. An in vitro binding assay showed that both huntingtin and P150 selectively bound to a glutathione transferase (GST)-HAP1 fusion protein. An immunoprecipitation assay demonstrated that P150 and huntingtin coprecipitated with HAP1 from rat brain cytosol. Western blot analysis revealed that HAP1 was enriched in rat brain microtubules and comigrated with P150 and huntingtin in sucrose gradients. Immunofluorescence showed that transfected HAP1 colocalized with P150 and huntingtin in human embryonic kidney (HEK) 293 cells. We propose that HAP1, P150, and huntingtin are present in a protein complex that may participate in dynein-dynactin- associated intracellular transport.