Since presenting our findings that disease-reversal could be observed in a conditional mouse model of Huntington's Disease, we have sought the key cellular events that led to this observation. Our current working hypothesis is that the elimination of accumulated protein is this key event. In the past funding period, we proposed that in order to test this hypothesis in vivo, first we had to use cell biology and biochemistry to identify the degradation pathway responsible, as well as to find a molecular regulator that would permit us to exert experimental control. As such, we have identified a selective form of macroautophagy that eliminates accumulating expanded polyglutamine proteins. Moreover, we determined that the protein Alfy was a key regulator of this pathway. For the next funding period, we propose to test our initial hypothesis by ascertaining the function of Alfy in the brain, and how altering its levels impacts reversal in our conditional model of HD. Further, we would like to broaden our findings by understanding how Alfy impacts the elimination of accumulating nuclear proteins, focusing on ataxin-1, and by determining if our working hypothesis is relevant in a true HD model which expresses the full length huntingtin protein.

Public Health Relevance

Our goal is to determine the key neuronal events that can lead to the amelioration of polyglutamine expansion disorders such as Huntington's disease (HD). We have identified a pathway that eliminates the accumulated protein in neurons and we will test whether this can have a beneficial effect on mouse models of HD.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS050199-07
Application #
7935486
Study Section
Cell Death in Neurodegeneration Study Section (CDIN)
Program Officer
Sutherland, Margaret L
Project Start
2004-09-20
Project End
2011-08-31
Budget Start
2010-09-01
Budget End
2011-08-31
Support Year
7
Fiscal Year
2010
Total Cost
$630,498
Indirect Cost
Name
Columbia University (N.Y.)
Department
Neurology
Type
Schools of Medicine
DUNS #
621889815
City
New York
State
NY
Country
United States
Zip Code
10032
Dragich, Joanna M; Kuwajima, Takaaki; Hirose-Ikeda, Megumi et al. (2016) Autophagy linked FYVE (Alfy/WDFY3) is required for establishing neuronal connectivity in the mammalian brain. Elife 5:
Shoji-Kawata, Sanae; Sumpter, Rhea; Leveno, Matthew et al. (2013) Identification of a candidate therapeutic autophagy-inducing peptide. Nature 494:201-6
Yamamoto, Ai; Simonsen, Anne (2011) The elimination of accumulated and aggregated proteins: a role for aggrephagy in neurodegeneration. Neurobiol Dis 43:17-28
Cremona, M Laura; Matthies, Heinrich J G; Pau, Kelvin et al. (2011) Flotillin-1 is essential for PKC-triggered endocytosis and membrane microdomain localization of DAT. Nat Neurosci 14:469-77
Yamamoto, Ai; Simonsen, Anne (2011) Alfy-dependent elimination of aggregated proteins by macroautophagy: can there be too much of a good thing? Autophagy 7:346-50
Filimonenko, Maria; Isakson, Pauline; Finley, Kim D et al. (2010) The selective macroautophagic degradation of aggregated proteins requires the PI3P-binding protein Alfy. Mol Cell 38:265-79
Varma, Hemant; Yamamoto, Ai; Sarantos, Melissa R et al. (2010) Mutant huntingtin alters cell fate in response to microtubule depolymerization via the GEF-H1-RhoA-ERK pathway. J Biol Chem 285:37445-57
Liu, Wencheng; Vives-Bauza, Cristofol; Acin-Perez-, Rebeca et al. (2009) PINK1 defect causes mitochondrial dysfunction, proteasomal deficit and alpha-synuclein aggregation in cell culture models of Parkinson's disease. PLoS One 4:e4597
Jeong, Hyunkyung; Then, Florian; Melia Jr, Thomas J et al. (2009) Acetylation targets mutant huntingtin to autophagosomes for degradation. Cell 137:60-72