Expression of mutant huntingtin blocks exocytosis in PC12 cells by depletion of complexin II.
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by an expanded CAG repeat in the HD gene. We reported recently that complexin II, a protein involved in neurotransmitter release, is depleted from both the brains of mice carrying the HD mutation and from the striatum of post mortem HD brains. Here we show that this loss of complexin II is recapitulated in PC12 cells expressing the HD mutation and is accompanied by a dramatic decline in Ca2+-triggered exocytosis of neurotransmitter. Overexpression of complexin II (but not complexin I) rescued exocytosis, demonstrating that the decline in neurotransmitter release is a direct consequence of complexin II depletion. Complexin II depletion in the brain may account for some of the abnormalities in neurotransmission associated with HD.
Edwardson
J Michael
JM
Department of Pharmacology, Tennis Court Road, Cambridge CB2 1PD, United Kingdom.
Wang
Chih-Tien
CT
Gong
Belvin
B
Wyttenbach
Andreas
A
Bai
Jihong
J
Jackson
Meyer B
MB
Chapman
Edwin R
ER
Morton
A Jennifer
AJ
D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D002118:Calcium / Q000378:metabolism; D005089:Exocytosis / Q000502:physiology*; D006801:Humans; D000071058:Huntingtin Protein; D051379:Mice; D008822:Mice, Transgenic; D009419:Nerve Tissue Proteins / Q000235:genetics* / Q000378:metabolism*; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D018377:Neurotransmitter Agents / Q000378:metabolism; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism*; D016716:PC12 Cells; D051381:Rats
D033942:Adaptor Proteins, Vesicular Transport; C086055:HTT protein, human; C506812:Htt protein, mouse; C499524:Htt protein, rat; D000071058:Huntingtin Protein; D009419:Nerve Tissue Proteins; D018377:Neurotransmitter Agents; D009687:Nuclear Proteins; C095993:complexin II; D002118:Calcium