Diseases involving disruptions in proper protein folding are termed """"""""conformational diseases."""""""" Proteins undergo misfolding due to mutation, stress or stochastic events. Misfolded proteins form aggregates and impact native (bystander) protein form and function. These disruptions to protein homeostasis are well known to be associated with neurological and prion diseases. Less known, however is the association between protein misfolding and certain diabetic phenotypes. The mechanisms of the impact of protein misfolding and aggregation on native protein formation and production are not well understood. One often observed occurrence in conformational diseases is a threshold phenomenon. Cellular aggregate levels are somehow driven across a threshold from nontoxic to toxic. Our long range goal is to elucidate the mechanism(s) of the impact of aggregate prone misfolded protein on bystander protein development. Our immediate goal is to further describe the conditions necessary for the threshold phenomenon observed in conformational diseases. Here, we present preliminary data of a general mathematical model describing the impact of misfolded protein on bystander protein production and the conditions for existence of a threshold phenomenon.
Two aims will examine how the threshold phenomenon manifests in conformational diseases:
Specific Aim 1 : Identify the key reaction motifs responsible for the manifestation of threshold phenomena in conformational diseases.
Specific Aim 2 : Evaluate the effects of protein fluxes on the dynamical behavior of native protein disappearance in conformational diseases.

Public Health Relevance

A disruption in cellular quality control processes can lead to the mismanagement of misfolded proteins, resulting in toxic protein aggregation and disease. Elevated levels of misfolded protein and associated aggregation are implicated in a variety of diseases such as Alzheimer's, Charcot-Marie-Tooth and diabetes mellitus. Understanding the detailed mechanisms behind protein misfolding and aggregation will lend insight into cellular quality control as well as into potential treatments for patients with protein misfolding diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
5F31GM096728-02
Application #
8265827
Study Section
Special Emphasis Panel (ZRG1-F04B-B (20))
Program Officer
Hagan, Ann A
Project Start
2011-04-01
Project End
2012-05-31
Budget Start
2012-04-01
Budget End
2012-05-31
Support Year
2
Fiscal Year
2012
Total Cost
$13,564
Indirect Cost
Name
University of Michigan Ann Arbor
Department
Physiology
Type
Schools of Medicine
DUNS #
073133571
City
Ann Arbor
State
MI
Country
United States
Zip Code
48109
Sandefur, Conner I; Mincheva, Maya; Schnell, Santiago (2013) Network representations and methods for the analysis of chemical and biochemical pathways. Mol Biosyst 9:2189-200
Sandefur, Conner I; Schnell, Santiago (2011) A model of threshold behavior reveals rescue mechanisms of bystander proteins in conformational diseases. Biophys J 100:1864-73