Autoregulation of RNA helicase operon expression

  • Author / Creator
    Rosana, Albert Remus Romero
  • The cyanobacterium Synechocystis sp. PCC 6803 encodes for an RNA helicase, crhR, whose expression is regulated by the redox status of the electron transport chain and further enhanced by temperature downshift. In this study, the effect of crhR inactivation was investigated in response to temperature alteration. The inactivation of CrhR has drastic morphological and physiological effects particularly under cold stress, including a rapid cessation of photosynthesis, impaired cell growth, decrease in viability, cell size and DNA content and accumulation of structural abnormalities. Extensive transcript and protein analyses between wild type and mutant cells revealed that CrhR activity is linked to its autoregulation of expression involving complex network acting at the transcriptional and post-transcriptional levels. Furthermore, autoregulation is extended to the rimO-crhR operon where processing and degradation contributes to differential accumulation of the cistrons. Lastly, the potential association of CrhR in a degradosome-polysome complex in the thylakoid membrane is proposed.

  • Subjects / Keywords
  • Graduation date
    Fall 2013
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.