Classification, Expression Pattern, and E3 Ligase Activity Assay of Rice U-Box-Containing Proteins
a Department of Plant Pathology, Plant Molecular Biology and Biotechnology Program, The Ohio State University, 2021 Coffey Rd, 201 Kottman Hall, Columbus, OH 43210, USA
b Present address: Boyce Thompson Institute for Plant Research, Tower Rd, Ithaca, NY 14853, USA
c Department of Computer Science, University of Bristol, Woodland Rd, Bristol BS8 1UB, UK
d Crop Gene Engineering Key Laboratory of Hunan Province, Hunan Agricultural University, Changsha, Hunan 410128, China
1 To whom correspondence should be addressed. E-mail wang.620{at}osu.edu, fax 614 292 4455, tel. 614 292 9280.
Ubiquitin ligases play a central role in determining the specificity of the ubiquitination system by selecting a myriad of appropriate candidate proteins for modification. The U-box is a recently identified, ubiquitin ligase activity-related protein domain that shows greater presence in plants than in other organisms. In this study, we identified 77 putative U-box proteins from the rice genome using a battery of whole genome analysis algorithms. Most of the U-box protein genes are expressed, as supported by the identification of their corresponding expressed sequence tags (ESTs), full-length cDNAs, or massively parallel signature sequencing (MPSS) tags. Using the same algorithms, we identified 61 U-box proteins from the Arabidopsis genome. The rice and Arabidopsis U-box proteins were classified into nine major classes based on their domain compositions. Comparison between rice and Arabidopsis U-box proteins indicates that the majority of rice and Arabidopsis U-box proteins have the same domain organizations. The inferred phylogeny established the homology between rice and Arabidopsis U-box/ARM proteins. Cell death assay using the rice protoplast system suggests that one rice U-box gene, OsPUB51, might act as a negative regulator of cell death signaling. In addition, the selected U-box proteins were found to be functional E3 ubiquitin ligases. The identification and analysis of rice U-box proteins hereby at the genomic level will help functionally characterize this class of E3 ubiquitin ligase in the future.
2 These authors contributed equally to the project.
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  D. Yee and D. R. Goring The diversity of plant U-box E3 ubiquitin ligases: from upstream activators to downstream target substrates J. Exp. Bot., March 1, 2009; 60(4): 1109 - 1121. [Abstract] [Full Text] [PDF]
|
|