Huntingtin facilitates dynein/dynactin-mediated vesicle transport.
Cytoplasmic dynein is a multisubunit microtubule motor complex that, together with its activator, dynactin, drives vesicular cargo toward the minus ends of microtubules. Huntingtin (Htt) is a vesicle-associated protein found in both neuronal and nonneuronal cells that is thought to be involved in vesicular transport. In this study, we demonstrate through yeast two-hybrid and affinity chromatography assays that Htt and dynein intermediate chain interact directly; endogenous Htt and dynein co-immunoprecipitate from mouse brain cytosol. Htt RNAi in HeLa cells results in Golgi disruption, similar to the effects of compromising dynein/dynactin function. In vitro studies reveal that Htt and dynein are both present on vesicles purified from mouse brain. Antibodies to Htt inhibited vesicular transport along microtubules, suggesting that Htt facilitates dynein-mediated vesicle motility. In vivo inhibition of dynein function results in a significant redistribution of Htt to the cell periphery, suggesting that dynein transports Htt-associated vesicles toward the cell center. Together these findings indicate that Htt binds to dynein and acts in a complex along with dynactin and Htt-associated protein-1 to facilitate vesicular transport.
Caviston
Juliane P
JP
Department of Physiology, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
Ross
Jennifer L
JL
Antony
Sheila M
SM
Tokito
Mariko
M
Holzbaur
Erika L F
EL
D000818:Animals; D001692:Biological Transport; D001923:Brain Chemistry; D002417:Cattle; D002846:Chromatography, Affinity; D022162:Cytoplasmic Vesicles / Q000378:metabolism*; D003600:Cytosol / Q000201:enzymology; D004398:Dyneins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D006056:Golgi Apparatus / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D000071058:Huntingtin Protein; D007150:Immunohistochemistry; D051379:Mice; D008822:Mice, Transgenic; D008870:Microtubules / Q000201:enzymology / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism* / Q000494:pharmacology; D009687:Nuclear Proteins / Q000378:metabolism* / Q000494:pharmacology; D011233:Precipitin Tests; D034622:RNA Interference; D012680:Sensitivity and Specificity; D020798:Two-Hybrid System Techniques
C086055:HTT protein, human; C506812:Htt protein, mouse; D000071058:Huntingtin Protein; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D004398:Dyneins