Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


case1264276011.pdf (4.05 MB)

ETD Abstract Container

Abstract Header

CIRCADIAN PROTEOME CHANGES IN PHOTORECEPTOR OUTER SEGMENTS

Leary, Dagmar Hajkova
http://rave.ohiolink.edu/etdc/view?acc_num=case1264276011

Abstract Details

2010, Doctor of Philosophy, Case Western Reserve University, Pharmacology.
The goal of this study was to better understand the molecular mechanisms of lightinduced photoreceptor cell death. Apoptotic photoreceptor cell death is the cause of several common retinal diseases (e.g. age related macular degeneration, retinitis pigmentosa). Light-induced photoreceptor cell degeneration in laboratory animals is one of the experimental models for studying such human retinal diseases. It begins with the absorption of light by rhodopsin in the photoreceptor outer segments (OS) which eventually leads to apoptotic photoreceptor cell death but the exact molecular mechanisms are yet to be elucidated. To gain insight into these mechanisms we investigated the light-induced and circadian changes in the OS proteome using a quantitative proteomic method called proteolytic 18O labeling. The first study investigated the changes of OS proteome upon intense light exposure. Rapigest, acid cleavable detergent, was used to solubilize OS proteins for tryptic digestion and 18O 16 labeling. The quantities of 11 proteins were found to differ by more than 2-fold upon light exposure. Eight proteins were phototransduction proteins and seven of these were altered to reduce efficiency or quench phototransduction during light exposure. In contrast, the amount of rhodopsin kinase was reduced by 2-fold after light exposure, suggesting attenuation in the mechanism of quenching phototransduction. Our findings suggest that this reduction may be a contributing factor to light-induced photoreceptor cell death. The second study investigated OS proteome differences between midnight and noon. This study was designed to elucidate the mechanisms of circadian dependent susceptibility to light induced damage, since the susceptibility is greater at night than daytime. OS proteins were fractionated by 1D-SDS-PAGE prior to 18O labeling. Most OS protein amounts remained unchanged at night versus daytime. The most notable difference was the lower amount of anti-stress proteins (crystallin αB, and peroxiredoxin 1) at midnight, suggesting the link with the greater nighttime OS susceptibility to light. Our studies create a foundation for understanding the mechanisms of light-induced photoreceptor cell death.
Masaru Miyagi, PhD. (Advisor)
Charles Hoppel, PhD. (Committee Chair)
Michael Maguire, PhD. (Committee Member)
Rob Ewing, PhD (Committee Member)
172 p.
Biomedical Research; Ophthalmology
18 O labeling; photoreceptor; outer segments; membrane proteins; proteomics; light induced apoptosis; cirdadian changes

Recommended Citations

Citations

  • Leary, D. H. (2010). CIRCADIAN PROTEOME CHANGES IN PHOTORECEPTOR OUTER SEGMENTS [Doctoral dissertation, Case Western Reserve University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=case1264276011

    APA Style (7th edition)

  • Leary, Dagmar. CIRCADIAN PROTEOME CHANGES IN PHOTORECEPTOR OUTER SEGMENTS. 2010. Case Western Reserve University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=case1264276011.

    MLA Style (8th edition)

  • Leary, Dagmar. "CIRCADIAN PROTEOME CHANGES IN PHOTORECEPTOR OUTER SEGMENTS." Doctoral dissertation, Case Western Reserve University, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1264276011

    Chicago Manual of Style (17th edition)

case1264276011
730
© 2010, all rights reserved.
This open access ETD is published by Case Western Reserve University School of Graduate Studies and OhioLINK.