Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: September 10, 2009
Publication Date: September 11, 2009
Citation: Chen, J. 2009. Dissection of the roles of FtsH protease in chloroplast biogenesis and stability at moderately high temperature: a quantitative proteomics approach[abstract]. Proteomics Workshop and Symposium. August 5-7, 2009, Gainesville, Florida. Technical Abstract: The chloroplast-targeted FtsH11 protease has been identified as essential for Arabidopsis survival at moderately high temperatures. The ftsh11 plants display a host of dramatic changes in photosynthetic parameters, cessation of growth and development, and eventual death if temperature exceeds 30ºC at any developmental stage. The etiolated cotyledons of ftsh11 are unable to turn green and develop typical thylakoid membranes if they are exposed to light at 30ºC and the thylakoids of mature chloroplasts in rosette leaves disintegrate after 4 to 5 d at 30ºC, suggesting a critical role for FtsH11 protease in chloroplast biogenesis and in maintaining stability of chloroplasts as growth temperatures increase above optimal. The unique contribution of FtsH11 to thermotolerance sets it apart from all other previously characterized Arabidopsis FtsH proteases which function exclusively to alleviate damage due to high light exposure. However, many basic but critical questions about this protease remain unanswered. Analysis of chloroplast protein complex on 2D BN/SDS-PAGE gel using intact chloroplasts isolated from control and 30C-stressed mutant and wildtype plants provided no clear clue to the specific impacts of FtsH11 protease on chloroplast proteins. High resolution techniques are needed to identify the specific proteins that are affected by FtsH11 protease. Identification of FtsH11 substrates, additional components in FtsH11 regulatory network and their dynamic changes in response to temperature increases will help us to decipher the role of FtsH11 in chloroplast biogenesis and thylakoid membrane stability at moderately elevated temperatures.