TY - JOUR
T1 - Three Arabidopsis genes encoding proteins with differential activities for cysteine synthase and β-cyanoalanine synthase
AU - Yamaguchi, Yube
AU - Nakamura, Tatsuo
AU - Kusano, Tomonobu
AU - Sano, Hiroshi
N1 - Funding Information:
The authors thank the Arabidopsis Biological Resource Center of Ohio State University for providing the EST clones 120I12T7, 135I12T7 and 166M10T7, Prof. N.M. Kredich (Duke University) and Prof. K. Saito (Chiba University) for providing E.coli NK3, Prof. N.H. Chua (Rockefeller University), Dr. P. Spielhofer (Berne University) and Dr. K. Hiratsuka (NAIST)*for supplying the GFP expression vector and technical advice and Dr. K. Akashi (NAIST) for supplying the AtHRS-GFP vector. This research was supported in part by a Grant-in-Aid for Scientific Research on Priority Areas from the Ministry of Education, Science and Culture, Japan (06271266) and a grant for Research for the Future Program (JSPS-RFTF 1997R16001) from the Japan Society for the Promotion of Science.
PY - 2000
Y1 - 2000
N2 - Three cDNA clones encoding putative cysteine synthases (O-acetylserine (thiol) lyase, EC 4.2.99.8) were isolated from Arabidopsis thaliana and designated AtcysC1, AtcysD1 and AtcysD2, respectively. Southern blot analyses suggested that the corresponding genes were present as a single copy, or at most two copies, in the A. thaliana genome. Escherichia coli complementation analyses confirmed that the cDNAs encode cysteine synthase and the corresponding proteins produced in E. coli clearly showed cysteine synthase activity. In addition, AtcysC1 protein showed β-cyanoalanine synthase (EC 4.4.1.9) activity, but the other two did not. Kinetic analysis suggests that AtcysC1 actually functions as β-cyanoalanine synthase rather than cysteine synthase in vivo. The mRNA accumulation of AtcysC1, AtcysD1 and AtcysD2 differed in various organs, but did not change markedly when A. thaliana seedlings were subjected to various stresses, including nutrient deprivation. In vivo targeting experiments indicated that AtcysD1 and AtcysD2 are cytoplasmic isozymes, and AtcysC1 is a mitochondrial isozyme.
AB - Three cDNA clones encoding putative cysteine synthases (O-acetylserine (thiol) lyase, EC 4.2.99.8) were isolated from Arabidopsis thaliana and designated AtcysC1, AtcysD1 and AtcysD2, respectively. Southern blot analyses suggested that the corresponding genes were present as a single copy, or at most two copies, in the A. thaliana genome. Escherichia coli complementation analyses confirmed that the cDNAs encode cysteine synthase and the corresponding proteins produced in E. coli clearly showed cysteine synthase activity. In addition, AtcysC1 protein showed β-cyanoalanine synthase (EC 4.4.1.9) activity, but the other two did not. Kinetic analysis suggests that AtcysC1 actually functions as β-cyanoalanine synthase rather than cysteine synthase in vivo. The mRNA accumulation of AtcysC1, AtcysD1 and AtcysD2 differed in various organs, but did not change markedly when A. thaliana seedlings were subjected to various stresses, including nutrient deprivation. In vivo targeting experiments indicated that AtcysD1 and AtcysD2 are cytoplasmic isozymes, and AtcysC1 is a mitochondrial isozyme.
KW - Arabidopsis thaliana
KW - Cysteine synthase
KW - Pyridoxal 5'-phosphate
KW - β-cyanoalanine synthase
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U2 - 10.1093/pcp/41.4.465
DO - 10.1093/pcp/41.4.465
M3 - Article
C2 - 10845460
AN - SCOPUS:0034074441
SN - 0032-0781
VL - 41
SP - 465
EP - 476
JO - Plant and Cell Physiology
JF - Plant and Cell Physiology
IS - 4
ER -