Journal
PLANT JOURNAL
Volume 60, Issue 1, Pages 68-78Publisher
WILEY
DOI: 10.1111/j.1365-313X.2009.03932.x
Keywords
26S proteasome; endoreduplication; cell size; 19S RP; leaf size; ploidy
Categories
Funding
- 21st century COE Hokkaido University
- Akiyama Foundation
- Japan Society for the Promotion of Science for Young Scientists
- [19657013]
- [19039001]
Ask authors/readers for more resources
The ubiquitin/26S proteasome pathway plays a central role in the degradation of short-lived regulatory proteins, to control many cellular events. To further understand this pathway, we focused on the RPT2 subunit of the 26S proteasome regulatory particle. The Arabidopsis genome contains two genes, AtRPT2a and AtRPT2b, which encode paralog molecules of the RPT2 subunit, with a difference of only three amino acids in the protein sequences. Both genes showed similar mRNA accumulation patterns. However, the rpt2a mutant showed a specific phenotype of enlarged leaves caused by increased cell size, in correlation with increased ploidy. Detailed analyses revealed that cell expansion is increased in the rpt2a mutant by extended endoreduplication early in leaf development. The transcription of genes encoding cell cycle-related components, for DNA replication licensing and the G2/M phase, was also promoted in the rpt2a mutant, suggesting that extended endoreduplication was caused by increased DNA replication, and disrupted regulation of the G2/M checkpoint, at the proliferation stage of leaf development.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available