Intermediate Filaments (IFs) are one of three major classes of cytoskeleton found in every cell, and one of the more abundant cellular proteins. Mutations in IF proteins are responsible for at least 85 different human diseases, including many protein aggregation diseases. However, the unusual physical properties of these proteins have precluded determination of crystal structure. Because of this we have no in-depth mechanistic understanding of normal IF function, nor how mutations are pathogenic. In this proposal we will use biophysical approaches to define IF structure with a goal of elucidating IF function, and the degree to which IF structure is conserved across IF classes. This in turn will open the door to understanding pathogenesis among IF proteins, particularly those with protein aggregation phenotypes. We have assembled a team of several technologies: CW SDSL EPR, Pulsed Field SDSL EPR, Computational Modeling, High resolution TEM (Cryo- and STEM) and X Ray Crystallography.

Public Health Relevance

Intermediate Filaments (IFs) are a major component of every vertebrate cell. IFs help cells resist mechanical and metabolic stresses, and have been implicated in more than 85 human diseases. However, we have no mechanistic understanding of IF biology because we lack structure for IFs. Moreover the same properties that make IFs stable, also contribute to their potential to cause proteins aggregation diseases. We will solve normal IF structure, so that we can understand the mechanisms of normal IF function, thus laying the groundwork for understanding how specific mutations are pathogenic.

National Institute of Health (NIH)
National Eye Institute (NEI)
Research Project (R01)
Project #
Application #
Study Section
Macromolecular Structure and Function C Study Section (MSFC)
Program Officer
Araj, Houmam H
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
University of California Davis
Anatomy/Cell Biology
Schools of Medicine
United States
Zip Code
Budamagunta, M S; Guo, F; Sun, N et al. (2018) Production of recombinant human tektin 1, 2, and 4 and in vitro assembly of human tektin 1. Cytoskeleton (Hoboken) 75:3-11
Liu, Lishan; Hess, John; Sahu, Indra D et al. (2016) Probing the Local Secondary Structure of Human Vimentin with Electron Spin Echo Envelope Modulation (ESEEM) Spectroscopy. J Phys Chem B 120:12321-12326
Hess, John F; Budamagunta, Madhu S; Aziz, Atya et al. (2013) Electron paramagnetic resonance analysis of the vimentin tail domain reveals points of order in a largely disordered region and conformational adaptation upon filament assembly. Protein Sci 22:47-55
Aziz, Atya; Hess, John F; Budamagunta, Madhu S et al. (2012) The structure of vimentin linker 1 and rod 1B domains characterized by site-directed spin-labeling electron paramagnetic resonance (SDSL-EPR) and X-ray crystallography. J Biol Chem 287:28349-61
Yoon, Kyoung-hye; FitzGerald, Paul G (2009) Periplakin interactions with lens intermediate and beaded filaments. Invest Ophthalmol Vis Sci 50:1283-9
Pittenger, Josh T; Hess, John F; Budamagunta, Madhu S et al. (2008) Identification of phosphorylation-induced changes in vimentin intermediate filaments by site-directed spin labeling and electron paramagnetic resonance. Biochemistry 47:10863-70
Pittenger, Joshua T; Hess, John F; Fitzgerald, Paul G (2007) Identifying the role of specific motifs in the lens fiber cell specific intermediate filament phakosin. Invest Ophthalmol Vis Sci 48:5132-41
Hess, John F; Budamagunta, Madhu S; Shipman, Rebecca L et al. (2006) Characterization of the linker 2 region in human vimentin using site-directed spin labeling and electron paramagnetic resonance. Biochemistry 45:11737-43