The mechanism regulating proteasomal activity under proteotoxic stress conditions remains unclear.Here,we showed that arsenite-induced proteotoxic stress resulted in upregulation of Arabidopsis homologous PUB22 and PU...The mechanism regulating proteasomal activity under proteotoxic stress conditions remains unclear.Here,we showed that arsenite-induced proteotoxic stress resulted in upregulation of Arabidopsis homologous PUB22 and PUB23 U-boxE3 ubiquitin ligases and that pub22 pub23 double mutants displayed arsenite-insensitive seed germination and root growth phenotypes.PUB22/PUB23 downregulated 26 S proteasome activity by promoting the dissociation of the 19 S regulatory particle from the holo-proteasome complex,resulting in intracellular accumulation of UbG76 VGFP,an artificial substrate of the proteasome complex,and insoluble poly-ubiquitinated proteins.These results suggest that PUB22/PUB23 play a critical role in arsenite-induced proteotoxic stress response via negative regulation of 26 S proteasome integrity.展开更多
Drought stress has detrimental effects on plants.Although the abscisic acid(ABA)-mediated drought response is well established,defensive mechanisms to cope with dehydration-induced proteotoxicity have been rarely stud...Drought stress has detrimental effects on plants.Although the abscisic acid(ABA)-mediated drought response is well established,defensive mechanisms to cope with dehydration-induced proteotoxicity have been rarely studied.DRR1 was identified as an Arabidopsis drought-induced gene encoding an ER-localized RING-type E3 Ub ligase.Suppression of DRR1 markedly reduced tolerance to drought and proteotoxic stress without altering ABA-mediated germination and stomatal movement.Proteotoxicityand dehydration-induced insoluble ubiquitinated protein accumulation was more obvious in DRR1 loss-of-function plants than in wild-type plants.These results suggest that DRR1 is involved in an ABA-independent drought stress response possibly through the mitigation of dehydration-induced proteotoxic stress.展开更多
It is a challenge to confirm chronic mesenteric ischemia(CMI) as a cause of gastrointestinal(GI) symptoms such as postprandial epigastric bloating,anorexia,and debilitating weight loss.Endovascular intervention for CM...It is a challenge to confirm chronic mesenteric ischemia(CMI) as a cause of gastrointestinal(GI) symptoms such as postprandial epigastric bloating,anorexia,and debilitating weight loss.Endovascular intervention for CMI has been gaining popularity because of the high morbidity associated with surgical revascularization.However,in EVI for superior mesenteric artery(SMA) occlusion,the transfemoral approach is limited by difficulty in coaxial alignment of the guiding catheter,which leads to insufficient back-up support.Herein,we report on a 58-year-old male patient with chronic total occlusion of the SMA,which was successfully revascularized by endovascular intervention via the left radial artery.Transradial endovascular therapy may be another treatment option for the treatment of CMI.展开更多
基金supported by grants from the National Research Foundation(Mid-Career Researcher Program Project No.2017R1A2B2006750 and Basic Science Research Program Project No.2018R1A6A1A03025607),Republic of Korea,to Woo T.Kim。
文摘The mechanism regulating proteasomal activity under proteotoxic stress conditions remains unclear.Here,we showed that arsenite-induced proteotoxic stress resulted in upregulation of Arabidopsis homologous PUB22 and PUB23 U-boxE3 ubiquitin ligases and that pub22 pub23 double mutants displayed arsenite-insensitive seed germination and root growth phenotypes.PUB22/PUB23 downregulated 26 S proteasome activity by promoting the dissociation of the 19 S regulatory particle from the holo-proteasome complex,resulting in intracellular accumulation of UbG76 VGFP,an artificial substrate of the proteasome complex,and insoluble poly-ubiquitinated proteins.These results suggest that PUB22/PUB23 play a critical role in arsenite-induced proteotoxic stress response via negative regulation of 26 S proteasome integrity.
基金supported by grants from the National Research Foundation(Mid-Career Researcher Program 2020R1A2B5B02001590 and Basic Science Research Program 2018R1A6A1A03025607,Republic of Korea)a Hyundai Motor Chung Mong-Koo Foundation Scholarship。
文摘Drought stress has detrimental effects on plants.Although the abscisic acid(ABA)-mediated drought response is well established,defensive mechanisms to cope with dehydration-induced proteotoxicity have been rarely studied.DRR1 was identified as an Arabidopsis drought-induced gene encoding an ER-localized RING-type E3 Ub ligase.Suppression of DRR1 markedly reduced tolerance to drought and proteotoxic stress without altering ABA-mediated germination and stomatal movement.Proteotoxicityand dehydration-induced insoluble ubiquitinated protein accumulation was more obvious in DRR1 loss-of-function plants than in wild-type plants.These results suggest that DRR1 is involved in an ABA-independent drought stress response possibly through the mitigation of dehydration-induced proteotoxic stress.
文摘It is a challenge to confirm chronic mesenteric ischemia(CMI) as a cause of gastrointestinal(GI) symptoms such as postprandial epigastric bloating,anorexia,and debilitating weight loss.Endovascular intervention for CMI has been gaining popularity because of the high morbidity associated with surgical revascularization.However,in EVI for superior mesenteric artery(SMA) occlusion,the transfemoral approach is limited by difficulty in coaxial alignment of the guiding catheter,which leads to insufficient back-up support.Herein,we report on a 58-year-old male patient with chronic total occlusion of the SMA,which was successfully revascularized by endovascular intervention via the left radial artery.Transradial endovascular therapy may be another treatment option for the treatment of CMI.
