2012 — 2013 |
Desantis, Morgan |
F31Activity Code Description: To provide predoctoral individuals with supervised research training in specified health and health-related areas leading toward the research degree (e.g., Ph.D.). |
Optimizing and Defining the Mechanism of Alpha-Synuclein Disaggregation by Hsp104 @ University of Pennsylvania
DESCRIPTION (provided by applicant): Misfolding and aggregation of the protein ?-synuclein (? -syn) is associated with Parkinson's Disease (PD), which is a devastating neurodegenerative movement disorder. In PD, ? -syn misfolds into an aberrant protein conformation, termed amyloid, which is highly stable, possesses a characteristic cross-?? structure, and is largely viewed to be an intractable condition. There is evidence that pre- amyloid oligomers of ? -syn possess greater toxicity than the fibers themselves. Furthermore, certain rare mutations of ? -syn are associated with familial forms of PD and often result in a decreased age of onset and increased severity of symptoms. These mutants have been shown to increase propensity of ? -syn aggregation or to increase the concentration of the pre-amyloid oligomers. A remarkable yeast protein, Hsp104, has been shown to ameliorate symptoms of ? -syn aggregation in a rat model of PD by disaggregating the ? -syn fibers and oligomers. However, high concentrations of Hsp104 were required to observe disaggregation, which reduces the effectiveness of this potential PD therapeutic. Additionally, it is not clear how Hsp104 is able to remodel ? -syn fibers and oligomers, which obscures ways in which this protein may be further developed to treat PD. We have isolated an Hsp104 mutant with even greater potency towards ? -syn fibers, which gives us confidence that Hsp104 will be eventually become a viable PD treatment. The goal of this proposal is to optimize Hsp104 for even higher anti-?? -syn fiber and oligomer activity. We plan on targeting both wild-type and disease associated mutants of ? -syn to ensure that Hsp104 can be used to treat all cases of PD. We also aim to understand the mechanism of Hsp104 disaggregation of ? -syn fibers and oligomers in order to facilitate even further optimization of Hsp104 as a PD therapeutic. PUBLIC HEALTH RELEVANCE: Parkinson's Disease is a devastating neurodegenerative disorder which is characterized by protein misfolding and aggregation in brain tissue. These misfolded proteins, termed amyloid, are very stable and difficult to clear. However, the yeast protein, Hsp104 is able to reverse protein misfolding and clear the amyloid aggregates. We are focusing on two things: First, we will optimize Hsp104 activity so it is more potent against the amyloid aggregates found in Parkinson's patients; and second, we will determine how Hsp104 functions.
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1 |
2018 — 2020 |
Desantis, Morgan |
K99Activity Code Description: To support the initial phase of a Career/Research Transition award program that provides 1-2 years of mentored support for highly motivated, advanced postdoctoral research scientists. R00Activity Code Description: To support the second phase of a Career/Research Transition award program that provides 1 -3 years of independent research support (R00) contingent on securing an independent research position. Award recipients will be expected to compete successfully for independent R01 support from the NIH during the R00 research transition award period. |
Mechanisms of Lis1 and Nude/L Regulation of the Molecular Motor Dynein @ University of California, San Diego
PROJECT SUMMARY/ABSTRACT Microtubule-based transport is required for cell division, cell migration, and for transport of a number of cellular cargoes. A number of neurodevelopmental and neurodegenerative diseases are caused by or associated with impaired microtubule-based transport. Cytoplasmic dynein 1 (dynein) is one of two molecular motor proteins that are responsible for microtubule-based transport. Dynein is a highly regulated motor and interacts with a number of adaptor proteins that modulate its function and activity. Mutations or copy number variations of dynein regulatory proteins also leads to neurodevelopmental diseases. Despite the importance to human health, mechanisms of how dynein is regulated are largely unknown. This proposal for an NIH K99/R00 Pathway to Independence Award seeks to understand how Lis1 and NudE/L, which are two regulators required for nearly every dynein function, modulate dynein activity. Impaired Lis1 and NudE/L function is implicated in a number of human diseases, including microcephaly, lissencephaly, schizophrenia, and autism. In Aim1 during the mentored phase of the award, Dr. DeSantis will determine how Lis1 and NudE/L alter dynein function using a combination of structural biology and pure protein reconstitution experiments. Phosphorylation of dynein, Lis1, and NudE/L alter their activity but the mechanism of how this occurs in unknown. During the independent phase of the award, Dr. DeSantis will also determine how post-translational modifications influence dynein, Lis1, and NudE/L activity. In Aim 2, Dr. DeSantis will identify novel dynein regulatory pathways using a combination of proteomics, cell biology, live cell imaging, and recombinant protein reconstitutions. Dr. DeSantis has already identified novel Lis1 and NudE/L interacting proteins and will elucidate their function and mechanism during the mentored and independent award phase. The results of this work will reveal mechanisms of dynein regulation, which has far reaching implications in human health and disease. Dr. DeSantis will receive training in cryo-electron microscopy in the K99 portion of the award. When combined with her background in biochemistry, cell biology, and live cell imaging, learning cryo-electron microscopy will empower Dr. DeSantis' research about mechanisms of motor protein regulation far beyond the duration of the K99/R00 award.
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0.951 |