Abstract Detail

Biotic and abiotic stress

Whitford, Denise S. [1], Rosana, Albert Remus R. [1], Owttrim, George W. [1].

Association of an abiotic stress-induced RNA helicase with the thylakoid membrane.

Understanding the regulation of cyanobacterial genetics and metabolism are important for the development of “green” technologies, including bioremediation and bioproduction of fuels and plastics. The model cyanobacterium, Synechocystis sp. PCC 6803, encodes a single DEAD-box RNA helicase in its genome, CrhR. RNA helicases function in all aspects of RNA metabolism, regulating a diverse range of cellular processes by rearranging RNA secondary structures by unwinding and, more rarely, annealing RNA duplexes, as well as by mediating RNA-protein interactions. Although many prokaryotic RNA helicases have recently been shown to function as part of multi-subunit protein complexes, with roles in translation initiation, ribosome biogenesis or assembly and the RNA degradosome, the cellular role of CrhR is unknown. CrhR is expressed at a basal level during normal cell growth and at an enhanced level when exposed to abiotic stresses, such as low temperature. Recent evidence suggests that CrhR may have multiple cellular roles, as it self-regulates its expression at a number of levels (Rosana et al., 2012, Tarrasova et al., 2014). Here we report that CrhR localizes to different cellular compartments with soluble and membrane-associated forms existing at all temperatures. The soluble form of CrhR co-sediments with two large protein complexes essential in RNA metabolism, the polysome and the RNA degradosome. The membrane form of CrhR localizes specifically to the region of the thylakoid membrane. This implies that CrhR alteration of RNA structure is required for thylakoid membrane function. Developing a greater understanding of the localization of CrhR to these intracellular structures will advance our understanding of how helicase alteration of RNA secondary structure functions in the stress regulation of gene expression.

Rosana et al., 2012. PLoS One. 7:e48683. Tarrasova et al., 2014. J Bacteriol. 196:1560-1568.

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

Keywords:
temperature stress
RNA Helicase
cyanobacteria
Thylakoid Membrane
Polysome
RNA Degradosome.

Presentation Type: Oral Paper:Papers for Topics
Session: 7
Location: Salon 13/14/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 10:45 AM
Number: 7011
Abstract ID:901
Candidate for Awards:CSPB President's Award for Best Student Presentation