VENOSA4, a human dNTPase SAMHD1 homolog, contributes to chloroplast development and abiotic stress tolerance

编号 040022301

推送时间 20200127

研究领域 森林培育 

年份 2020 

类型 期刊 

语种 英语

标题 VENOSA4, a human dNTPase SAMHD1 homolog, contributes to chloroplast development and abiotic stress tolerance

来源期刊 Plant Physiology

期 第223期

发表时间 20191202

关键词 VENOSA4;  chloroplast;  abiotic stress tolerance;  dNTP; 

摘要 Chloroplast biogenesis depends on an extensive interplay between the nucleus, cytosol and chloroplasts, involving regulatory nucleus-encoded chloroplast proteins, as well as nucleocytosolic photoreceptors such as phytochromes (phys) and other extrachloroplastic factors. However, this whole process is only partially understood. Here, we describe the role of VENOSA4 (VEN4) in chloroplast development and acclimation to adverse growth conditions. A 35S:VEN4-eGFP fusion protein localizes to the nucleus in Arabidopsis protoplasts, and VEN4 homologues are present in a wide range of eukaryotes including humans, where the corresponding homolog (SAMHD1) cleaves dNTPs. Defective photosynthesis in ven4 seedlings results from reduced accumulation of photosynthetic proteins and appears to be caused by a reduction in the translational capacity of chloroplasts. The negative effect of the ven4 mutation on photosynthesis can be phenotypically suppressed by germinating seeds in the presence of excess dCTP or a pool of dNTPs, implying that VEN4, like human SAMHD1, is involved in dNTP catabolism. Moreover, VEN4 activity is also required for optimal responses to cold and salt stresses. In conclusion, our work emphasizes the importance of the nucleocytosolic compartment and the fine-tuning of dNTP levels for chloroplast translation and development.

服务人员 孙小满

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