Arabidopsis HIPP proteins regulate endoplasmic reticulum-associated degradation of CKX proteins and cytokinin responses

编号 040031104

推送时间 20211004

研究领域 森林培育 

年份 2021 

类型 期刊 

语种 英语

标题 Arabidopsis HIPP proteins regulate endoplasmic reticulum-associated degradation of CKX proteins and cytokinin responses

来源期刊 Molecular Plant

期 第311期

发表时间 20210723

关键词 proteins regulate;  Endoplasmic reticulum (ER);  CKX proteins;  plant development; 

摘要 Eukaryotic organisms are equipped with quality-control mechanisms that survey protein folding in the endoplasmic reticulum (ER) and remove non-native proteins by ER-associated degradation (ERAD). Recent research has shown that cytokinin-degrading CKX proteins are subjected to ERAD during plant development. The mechanisms of plant ERAD, including the export of substrate proteins from the ER, are not fully understood and the molecular components involved in the ERAD of CKX are unknown. We show that heavy metal-associated isoprenylated plant proteins (HIPP) interact specifically with CKX proteins synthesized in the ER and processed by ERAD. CKX-HIPP protein complexes were detected at the ER as well as in the cytosol, suggesting that the complexes involve retrotranslocated CKX protein species. Altered CKX levels in HIPP-overexpressing and higher-order hipp mutant plants suggest that the studied HIPP proteins control the ERAD of CKX. Deregulation of CKX proteins caused corresponding changes in the cytokinin signaling activity and triggered typical morphological cytokinin responses. Notably, transcriptional repression of HIPP genes by cytokinin indicates a feedback regulatory mechanism of cytokinin homeostasis and signaling responses. Moreover, the loss of HIPP genes constitutively activates the unfolded protein response and compromises the ER stress tolerance, supporting the conclusion that HIPPs represent novel functional components of plant ERAD.

服务人员 孙小满

服务院士 尹伟伦

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