N-terminal acetylation stabilizes SIGMA FACTOR BINDING PROTEIN 1 involved in salicylic acid-primed cell death

编号 040023902

推送时间 20200518

研究领域 森林培育 

年份 2020 

类型 期刊 

语种 英语

标题 N-terminal acetylation stabilizes SIGMA FACTOR BINDING PROTEIN 1 involved in salicylic acid-primed cell death

来源期刊 Plant Physiology

期 第239期

发表时间 20200305

关键词 N-terminal acetylation;  SIB1 protein stability;  salicylic acid-primed;  cell death; 

摘要 N-terminal (Nt) acetylation (NTA) is an ample and irreversible co-translational protein modification catalyzed by ribosome-associated Nt-acetyltransferases (NATs). NTA on specific proteins can act as a degradation signal (called an Ac/N-degron) for proteolysis in yeast and mammals. However, in plants, the biological relevance of NTA remains largely unexplored. In this study, we reveal that Arabidopsis thaliana SIGMA FACTOR-BINDING PROTEIN 1 (SIB1), a transcription co-regulator and a positive regulator of salicylic acid-primed cell death, undergoes an absolute NTA on the initiator methionine; Nt-acetyltransferase B (NatB) partly contributes to this modification. While NTA results in destabilization of certain target proteins, our genetic and biochemical analyses revealed that plant NatB-involved NTA instead renders SIB1 more stable. Given that the ubiquitin/proteasome system stimulates SIB1 degradation, it seems that the NTA-conferred stability ensures the timely expression of SIB1-dependent genes, mostly related to immune responses. Taking our findings together, here we report a non-canonical NTA-driven protein stabilization in land plants.

服务人员 孙小满

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