Effect of calpain on tau polymerization in vitro
Dr. Aida Abraha

Dr. Aida Abraha
Department of Chemistry and Physics

Tau is a microtubule-associated protein (MAP) that is predominantly found in the central nervous system (CNS). Tau is involved in promoting microtubule assembly and microtubule stabilization, in vivo. Microtubules are involved in maintaining the cell shape and serve as tracks for axonal transport. Post-translational modifications such as hyperphosphorylation and truncation are known causes of tau protein aggregating into intraneuronal filamentous inclusions in a number of neurodegenerative diseases including Alzheimer's disease (AD). Alzheimer's disease is a progressive dementing disorder that leads to severe memory loss and other behavioral abnormalities. It is the leading cause of dementia in the western world. In AD, these filamentous inclusions are known as neurofibrillary tangles (NFTs). NFTs are comprised of paired helical filaments (PHFs) and straight filaments (SFs). Numerous studies have investigated the relationship between the build up of NFTs and tau proteolysis via different proteases. Studies that investigated tau truncation by calpains have reported differential degradation of different forms of tau protein. Though it is known that calpains do cleave tau proteins in vitro, it has not been reported if these cleavages affect tau self-assembly. Hence, this project will investigate the biochemical changes in tau polymerization resulting from proteolysis by calpains 1 and 2 in vitro.

Dr. Abraha with her students and technician Doris Gana

Dr. Abraha (far right) with (from the left) technician Doris Gana and RISE interthur Thomas and Danielle Johnson.

Recent Publications & Presentations

Publications

 Berry, R. W.; Abraha, A.; Lagalwar, S.; LaPointe, N.; Gamblin, T. C.; Cryns, V. L.; Binder, L. I.    Department of Cell and Molecular Biology, Cognitive Neurology and Alzheimer's Disease Center and Division of Endocrinology Metabolism and Molecular Medicine, Feinberg School of Medicine,  Northwestern University,  Chicago,  IL,  USA.  Inhibition of Tau Polymerization by Its Carboxy-Terminal Caspase Cleavage Fragment.    Biochemistry  (2003),  42(27),  8325-8331. 

Presentations

Aida Abraha. Effect of calpain on tau polymerization in vitro and in Alzheimer’s disease. Society for Neuroscience Chicago Chapter, Chicago, IL, March 3, 2006.

Danielle Johnson, Arthur, Thomas, Acho Gana and Aida Abraha. Effect of calpain on tau polymerization in vitro and in Alzheimer’s disease.  Minority Trainee Research Forum (MTRF); Ft. Lauderdale, FL; Sept 7-11, 2005.

Danielle Johnson, Artur Thomas, Acho Gana and Aida Abraha. The effect of truncation on tau polymerization in vitro an in Alzheimer’s disease.  8th Annual Illinois LS-AMP Student Research Symposium; March 18-19, 2005; Oakbrook, IL.

 Abraha, A. was an invited discussion leader at the 8th Annual Joint IMGIP/ICEOP Conference, November 4-7 2004; Lincolnshire, IL.

Abraha, A., Carrington, J., Thomas, A., AThe Effect of Truncation on Tau Polymerization in Vitro and in Alzheimer's Disease, The National Institute of Health Midwest Regional Bridges Conference; October 1-2, 2004; Oakbrook, IL.

Abraha, A., Carrington, J., Thomas, A., AThe Effect of Truncation on Tau Polymerization in Vitro and in Alzheimer's Disease, 15th Annual Illinois Student Research Conference, Northeastern Illinois, 2004.

Carrington, J., and Abraha, A., AThe Effect of Truncation on Tau Polymerization in Vitro and in Alzheimer's Disease, 7th Annual LSAMP Student Research Symposium, Oakbrook IL, 2004.

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