TY - JOUR
T1 - PUB22 and PUB23 U-BOX E3 ligases directly ubiquitinate RPN6, a 26S proteasome lid subunit, for subsequent degradation in Arabidopsis thaliana
AU - Cho, Seok Keun
AU - Bae, Hansol
AU - Ryu, Moonyoung
AU - Yang, Seong Wook
AU - Kim, Woo Taek
PY - 2015/9/4
Y1 - 2015/9/4
N2 - Drought stress strongly affects plant growth and development, directly connected with crop yields, accordingly. However, related to the function of U-BOX E3 ligases, the underlying molecular mechanisms of desiccation stress response in plants are still largely unknown. Here we report that PUB22 and PUB23, two U-box E3 ligase homologs, tether ubiquitins to 19S proteasome regulatory particle (RP) subunit RPN6, leading to its degradation. RPN6 was identified as an interacting substrate of PUB22 by yeast two-hybrid screening, and in vitro pull-down assay confirmed that RPN6 interacts not only with PUB22, but also with PUB23. Both PUB22 and PUB23 were able to conjugate ubiquitins on RPN6 in vitro. Furthermore, RPN6 showed a shorter protein half-life in PUB22 overexpressing plants than in wild-type, besides RPN6 was significantly stabilized in pub22pub23 double knockout plants. Taken together, these results solidify a notion that PUB22 and PUB23 can alter the activity of 26S proteasome in response to drought stress.
AB - Drought stress strongly affects plant growth and development, directly connected with crop yields, accordingly. However, related to the function of U-BOX E3 ligases, the underlying molecular mechanisms of desiccation stress response in plants are still largely unknown. Here we report that PUB22 and PUB23, two U-box E3 ligase homologs, tether ubiquitins to 19S proteasome regulatory particle (RP) subunit RPN6, leading to its degradation. RPN6 was identified as an interacting substrate of PUB22 by yeast two-hybrid screening, and in vitro pull-down assay confirmed that RPN6 interacts not only with PUB22, but also with PUB23. Both PUB22 and PUB23 were able to conjugate ubiquitins on RPN6 in vitro. Furthermore, RPN6 showed a shorter protein half-life in PUB22 overexpressing plants than in wild-type, besides RPN6 was significantly stabilized in pub22pub23 double knockout plants. Taken together, these results solidify a notion that PUB22 and PUB23 can alter the activity of 26S proteasome in response to drought stress.
KW - 26S proteasome lid complex
KW - Drought stress
KW - RPN6
KW - U-BOX E3 ligase
KW - Ubiquitin-proteasome system
U2 - 10.1016/j.bbrc.2015.07.030
DO - 10.1016/j.bbrc.2015.07.030
M3 - Journal article
C2 - 26188517
AN - SCOPUS:84940459541
SN - 0006-291X
VL - 464
SP - 994
EP - 999
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 4
ER -