ATP synthases in chloroplasts （cpATPase） and mitochondria （mtATPase） are responsible for ATP production during photosynthesis and oxidative phosphorylation, respectively. Both enzymes consist of two multi- subunit...ATP synthases in chloroplasts （cpATPase） and mitochondria （mtATPase） are responsible for ATP production during photosynthesis and oxidative phosphorylation, respectively. Both enzymes consist of two multi- subunit complexes, the membrane-bound coupling factor O and the soluble coupling factor 1. During cpATPase biosynthesis, several accessory factors facilitate subunit production and orchestrate complex assembly. Here, we describe a new auxiliary protein in Arabidopsis thaliana, which is required for cpATPase accumulation. AtCGLD11 （CONSERVED IN THE GREEN LINEAGE AND DIATOMS 11） is a protein without any known functional domain and shows dual localization to chloroplasts and mitochondria. Loss of AtCGLDll function results in reduced levels of cpATPase and impaired photosynthetic performance with lower rates of ATP synthesis. In yeast two-hybrid experiments, AtCGLD11 interacts with the 13 subunits of the cpATPase and mtATPase. Our results suggest that AtCGLD11 functions in F1 assembly during cpATPase biogenesis, while its role in mtATPase biosynthesis may not, or not yet, be essential.展开更多
The subunit Ⅱ of chloroplast ATP synthase is one of the two peripheral stalks, which associates the catalytic CF1 with mem-brane-spanning CFo . Although the structural and functional roles of chloroplast ATP synthase...The subunit Ⅱ of chloroplast ATP synthase is one of the two peripheral stalks, which associates the catalytic CF1 with mem-brane-spanning CFo . Although the structural and functional roles of chloroplast ATP synthase have been extensively examined, the physiological significance of subunit Ⅱ in vivo is still unclear. In this work, we identified one Arabidopsis T-DNA insertion mutant of atpG gene encoding the subunit Ⅱ of chloroplast ATP synthase. The atpg null mutant displayed an albino lethal pheno-type, as it could not grow photoautotrophically. Transmission electron microscopy analysis showed that chloroplasts of atpg lacked the organized thylakoid membranes. Loss of subunit Ⅱ affected the accumulation of CF1-CFo complex, however, it did not seem to have an effect on the CF1 assembly. The light induced ATP formation of atpg was significantly reduced compared with the wild type. Based on these results, we suggested that ATPG was essential for the accumulation and function of chloroplast ATP synthase.展开更多
文摘ATP synthases in chloroplasts （cpATPase） and mitochondria （mtATPase） are responsible for ATP production during photosynthesis and oxidative phosphorylation, respectively. Both enzymes consist of two multi- subunit complexes, the membrane-bound coupling factor O and the soluble coupling factor 1. During cpATPase biosynthesis, several accessory factors facilitate subunit production and orchestrate complex assembly. Here, we describe a new auxiliary protein in Arabidopsis thaliana, which is required for cpATPase accumulation. AtCGLD11 （CONSERVED IN THE GREEN LINEAGE AND DIATOMS 11） is a protein without any known functional domain and shows dual localization to chloroplasts and mitochondria. Loss of AtCGLDll function results in reduced levels of cpATPase and impaired photosynthetic performance with lower rates of ATP synthesis. In yeast two-hybrid experiments, AtCGLD11 interacts with the 13 subunits of the cpATPase and mtATPase. Our results suggest that AtCGLD11 functions in F1 assembly during cpATPase biogenesis, while its role in mtATPase biosynthesis may not, or not yet, be essential.
基金supported by the National Natural Science Foundation of China (31070215 and 31100181)the State Key Basic Research and Development Program of China (2009CB118504)
文摘The subunit Ⅱ of chloroplast ATP synthase is one of the two peripheral stalks, which associates the catalytic CF1 with mem-brane-spanning CFo . Although the structural and functional roles of chloroplast ATP synthase have been extensively examined, the physiological significance of subunit Ⅱ in vivo is still unclear. In this work, we identified one Arabidopsis T-DNA insertion mutant of atpG gene encoding the subunit Ⅱ of chloroplast ATP synthase. The atpg null mutant displayed an albino lethal pheno-type, as it could not grow photoautotrophically. Transmission electron microscopy analysis showed that chloroplasts of atpg lacked the organized thylakoid membranes. Loss of subunit Ⅱ affected the accumulation of CF1-CFo complex, however, it did not seem to have an effect on the CF1 assembly. The light induced ATP formation of atpg was significantly reduced compared with the wild type. Based on these results, we suggested that ATPG was essential for the accumulation and function of chloroplast ATP synthase.
