Classification and interaction modes of 40 rice E2 ubiquitin-conjugating enzymes with 17 rice ARM-U-box E3 ubiquitin ligases.
Rice, a monocot model crop, contains at least 48 putative E2 ubiquitin (Ub)-conjugating enzymes. Based on homology comparisons with 40 Arabidopsis E2 proteins and 35 human E2s, 48 rice E2s were classified into 15 different groups. Yeast two-hybrid analyses using the U-box-domain regions of armadillo (ARM)-U-box E3 Ub-ligases and the Ub-conjugating (UBC) domains of E2s showed that, among 40 rice E2s, 11 E2s accounted for 70% of the interactions with 17 ARM-U-box E3s. Thus, a single E2 could interact with multiple ARM-U-box E3s, suggesting the presence of E2 hubs for E2-E3 interactions in rice. Rice SPL11 ARM-U-box E3 displayed distinct self-ubiquitination patterns, including poly-ubiquitination, mono-ubiquitination, or no ubiquitination, depending on different E2 partners. This suggests that the mode of ubiquitination of SPL11 E3 is critically influenced by individual E2s.
Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea.
Hansol
H
Bae
Department of Systems Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea. Electronic address: wtkim@yonsei.ac.kr.
Woo Taek
WT
Kim
D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D060066:Protein Interaction Maps; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*; D054875:Ubiquitination
D010940:Plant Proteins; D044763:Ubiquitin-Conjugating Enzymes; D044767:Ubiquitin-Protein Ligases
ARM-U-box E3 ubiquitin-ligase; E2 ubiquitin-conjugating enzyme; E2–E3 interaction; Rice (Oryza sativa L.); Ubiquitination