Downregulation of Rubisco Activity by Non-enzymatic Acetylation of RbcL.
Atmospheric carbon dioxide (CO2) is assimilated by the most abundant but sluggish enzyme, ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco). Here we show that acetylation of lysine residues of the Rubisco large subunit (RbcL), including Lys201 and Lys334 in the active sites, may be an important mechanism in the regulation of Rubisco activities. It is well known that Lys201 reacts with CO2 for carbamylation, a prerequisite for both carboxylase and oxygenase activities of Rubisco, and Lys334 contacts with ribulose-1,5-bisphosphate (RuBP). The acetylation level of RbcL in plants is lower during the day and higher at night, inversely correlating with the Rubisco carboxylation activity. A search of the chloroplast proteome database did not reveal a canonical acetyltransferase; instead, we found that a plant-derived metabolite, 7-acetoxy-4-methylcoumarin (AMC), can non-enzymatically acetylate both native Rubisco and synthesized RbcL peptides spanning Lys334 or Lys201. Furthermore, lysine residues were modified by synthesized 4-methylumbelliferone esters with different electro- and stereo-substitutes, resulting in varied Rubisco activities. 1-Chloroethyl 4-methylcoumarin-7-yl carbonate (ClMC) could transfer the chloroethyl carbamate group to lysine residues of RbcL and completely inactivate Rubisco, whereas bis(4-methylcoumarin-7-yl) carbonate (BMC) improved Rubisco activity through increasing the level of Lys201 carbamylation. Our findings indicate that RbcL acetylation negatively regulates Rubisco activity, and metabolic derivatives can be designed to dissect and improve CO2 fixation efficiency of plants through lysine modification.
State Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, 200032 Shanghai, China; University of Chinese Academy of Sciences, 200032 Shanghai, China.
Xiang
X
Gao
State Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, 200032 Shanghai, China; University of Chinese Academy of Sciences, 200032 Shanghai, China.
Hui
H
Hong
CAS Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, 200032 Shanghai, China; University of Chinese Academy of Sciences, 200032 Shanghai, China.
Wei-Chao
WC
Li
Laboratory of Photosynthesis and Environmental Biology, Shanghai Institute for Biological Sciences, 200032 Shanghai, China; University of Chinese Academy of Sciences, 200032 Shanghai, China.
Lili
L
Yang
State Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, 200032 Shanghai, China; Laboratory of Photosynthesis and Environmental Biology, Shanghai Institute for Biological Sciences, 200032 Shanghai, China.
Jirong
J
Huang
CAS Laboratory of Synthetic Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, 200032 Shanghai, China.
You-Li
YL
Xiao
State Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, 200032 Shanghai, China. Electronic address: xychen@sibs.ac.cn.
Xiao-Ya
XY
Chen
Laboratory of Photosynthesis and Environmental Biology, Shanghai Institute for Biological Sciences, 200032 Shanghai, China. Electronic address: chenggy@sibs.ac.cn.
Gen-Yun
GY
Chen
D000107:Acetylation; D017033:Anabaena / Q000235:genetics / Q000378:metabolism; D012275:Oryza / Q000235:genetics / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D012273:Ribulose-Bisphosphate Carboxylase / Q000378:metabolism*; D018724:Spinacia oleracea / Q000235:genetics / Q000378:metabolism; D046939:Synechocystis / Q000235:genetics / Q000378:metabolism; D053719:Tandem Mass Spectrometry; D003313:Zea mays / Q000235:genetics / Q000378:metabolism
D010940:Plant Proteins; D012273:Ribulose-Bisphosphate Carboxylase
4-methylumbelliferone esters; Lys201; Lys334; lysine acetylation; rubisco