Abstract Detail

Biotic and abiotic stress

Whitman, Brendan [1], Diep, Raymond [1], Whitford, Denise S. [1], Fahlman, Richard P. [2], Owttrim, George W. [1].

Stress induced regulation of gene expression by RNA helicase-dependent conditional proteolysis.

Cyanobacteria represent an ancient, diverse and ecologically significant phylum of bacteria. Their evolutionary success suggests an ability to adapt and flourish under changing environmental conditions. RNA helicases are highly conserved enzymes from bacteria to humans that play a role in all aspects of RNA metabolism, yet their potentially broad physiological functions in the cell both under ideal growth conditions and during stress have not been characterized. We have previously shown that the abundance of the cyanobacterial RNA helicase, CrhR, rapidly decreases in response to a temperature upshift from 20 to 30°C in the cyanobacterium Synechocystis sp. PCC 6803. Here we utilized a combination of whole cell proteomic analysis and a Western detection approach to track proteome changes in Synechocystis during a temperature upshift in both wild-type cells and a crhR mutant. The results identified a limited number of proteins whose abundance decreased and also a subset that increased in response to temperature stress. These gene expression changes were only observed in the biochemically active crhR wild-type strain, linking them with RNA helicase-mediated alteration of RNA secondary structure. Protein-protein associations within the dataset indicate clusters of proteins involved in translation and energy metabolism. Overall the data suggest that CrhR is intimately tied to temperature specific physiological changes in Synechocystis cells that target these two crucial processes. These findings help bridge the gap between known RNA helicase alterations to RNA secondary structure and thermotolerance pathways in cyanobacteria.

1 - University of Alberta, Department of Biological Sciences, CW 405, Biological Sciences Bldg, University of Alberta, Edmonton, AB, T6G 2E9 , Canada
2 - University of Alberta, Department of Biochemistry, 474 Medical Sciences Bldg, University of Alberta, Edmonton, AB, T6G 2H7, Canada

Keywords:
temperature stress
RNA Helicase
cyanobacteria
Proteolysis.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PBA008
Abstract ID:911
Candidate for Awards:CSPB President's Award for Best Student Presentation