Novel Mechanism of Post-transcriptional Regulation in Nutritional Response

2014 Fiscal Year Final Research Report

• Project Area: Integrated analysis of strategies for plant survival and growth in response to global environmental changes
• Project/Area Number: 22119006
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Biological Sciences
• Research Institution: Hokkaido University
• Principal Investigator: NAITO Satoshi 北海道大学, (連合)農学研究科(研究院), 教授 (20164105)
• Project Period (FY): 2010-04-01 – 2015-03-31
• Keywords: mRNA分解 / リボソーム / 翻訳停止 / 試験管内翻訳系 / シロイヌナズナ

Outline of Final Research Achievements

Cystathionine γ-synthase (CGS) catalyzes the first committed step of methionine biosynthesis in plants. Expression of CGS1 gene that encodes CGS is feedback-regulated, in response to S-adenosyl-L-methonine (SAM), by translation arrest at Ser-94 codon followed by mRNA degradation. Studies using in vitro translation system revealed that nascent peptide of CGS1 takes compact conformation upon translation arrest, and conformation of 28S rRNA and/or interaction between the nascent peptide and rRNA changes. Upon translation arrest, ribosomes are stacked behind the initially arrested ribosome at Ser-94. We revealed that the stacked ribosomes are arranged at nine codon intervals.
During general mRNA degradation, poly(A) shortening is the first and usually the rate-limiting step. In SAM-induced CGS1 mRNA degradation, however, the poly(A) shortening was not observed.

Free Research Field

分子遺伝学