TY - JOUR
T1 - In vitro and in vivo interaction of AtRma2 E3 ubiquitin ligase and auxin binding protein 1
AU - Son, Ora
AU - Cho, Seok Keun
AU - Kim, Soo Jin
AU - Kim, Woo Taek
PY - 2010/3/12
Y1 - 2010/3/12
N2 - E3 ubiquitin (Ub) ligases play diverse roles in cellular regulation in eukaryotes. Three homologous AtRmas (AtRma1, AtRma2, and AtRma3) were recently identified as ER-localized Arabidopsis homologs of human RING membrane-anchor E3 Ub ligase. Here, auxin binding protein 1 (ABP1), one of the auxin receptors in Arabidopsis, was identified as a potential substrate of AtRma2 through a yeast two-hybrid assay. An in vitro pull-down assay confirmed the interaction of full-length AtRma2 with ABP1. AtRma2 was transiently expressed in tobacco (Nicotiana benthamiana) plants through an Agrobacterium-mediated infiltration method and bound ABP1 in vivo. In vitro ubiquitination assays revealed that bacterially-expressed AtRma2 ubiquitinated ABP1. ABP1 was poly-ubiquitinated in tobacco cells and its stability was significantly increased in the presence of MG132, a 26S proteasome inhibitor. This suggests that ABP1 is controlled by the Ub/26S proteasome system. Therefore, AtRma2 is likely involved in the cellular regulation of ABP1 expression levels.
AB - E3 ubiquitin (Ub) ligases play diverse roles in cellular regulation in eukaryotes. Three homologous AtRmas (AtRma1, AtRma2, and AtRma3) were recently identified as ER-localized Arabidopsis homologs of human RING membrane-anchor E3 Ub ligase. Here, auxin binding protein 1 (ABP1), one of the auxin receptors in Arabidopsis, was identified as a potential substrate of AtRma2 through a yeast two-hybrid assay. An in vitro pull-down assay confirmed the interaction of full-length AtRma2 with ABP1. AtRma2 was transiently expressed in tobacco (Nicotiana benthamiana) plants through an Agrobacterium-mediated infiltration method and bound ABP1 in vivo. In vitro ubiquitination assays revealed that bacterially-expressed AtRma2 ubiquitinated ABP1. ABP1 was poly-ubiquitinated in tobacco cells and its stability was significantly increased in the presence of MG132, a 26S proteasome inhibitor. This suggests that ABP1 is controlled by the Ub/26S proteasome system. Therefore, AtRma2 is likely involved in the cellular regulation of ABP1 expression levels.
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U2 - 10.1016/j.bbrc.2010.02.032
DO - 10.1016/j.bbrc.2010.02.032
M3 - Article
C2 - 20152813
AN - SCOPUS:77949264238
SN - 0006-291X
VL - 393
SP - 492
EP - 497
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 3
ER -