Functional characterization of DEAD-box RNA helicase 7, AtRH7, in Arabidopsis

• Main Authors: Yu-lien Shen, 沈育年
• Other Authors: Chung-an Lu
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/7254cn

碩士 === 國立中央大學 === 生命科學系 === 102 === DEAD box RNA helicases belong to a protein family that plays specific roles in various RNA metabolism processes, including ribosome biogenesis, mRNA splicing, RNA export, mRNA translation, and RNA decay. This study investigated a DEAD box RNA helicase, AtRH7/PRH75, in Arabidopsis. The AtRH7/PRH75 expression was ubiquitous, was activated in the cell-dividing region, and was induced by cold stress. The phenotypes of 2 allelic AtRH7/PRH75-knockout mutants, atrh7-2 and atrh7-3, resembled the auxin-related developmental defects exhibited in several ribosomal protein mutants and were more severe under cold stress. The atrh7 mutants exhibited decreased CBF1, CBF2, and CBF3 expression, which could be responsible for the subsequent cold intolerance; they also exhibited unprocessed 18S pre-rRNA accumulation. By a circular RT-PCR analysis displayed the accumulated 18S pre-rRNA, indicating that rRNA processing ceased at the A2 site. The atrh7 mutants were hyposensitive to the antibiotics that target to ribosomal small subunits, suggesting that AtRH7 was also involved in ribosome assembly. Taken together, our studies indicate that the AtRH7 participates in A2 site processing of rRNA biogenesis and ribosome assembling, and involves in plant development and cold stress tolerance in Arabidopsis.