Group 3 sigma factor gene, sigJ, a key regulator of desiccation tolerance, regulates the synthesis of extracellular polysaccharide in cyanobacterium Anabaena sp. strain PCC 7120.
The changes in the expression of sigma factor genes during dehydration in terrestrial Nostoc HK-01 and aquatic Anabaena PCC 7120 were determined. The expression of the sigJ gene in terrestrial Nostoc HK-01, which is homologous to sigJ (alr0277) in aquatic Anabaena PCC 7120, was significantly induced in the mid-stage of dehydration. We constructed a higher-expressing transformant of the sigJ gene (HE0277) in Anabaena PCC 7120, and the transformant acquired desiccation tolerance. The results of Anabaena oligonucleotide microarray experiments showed that a comparatively large number of genes relating to polysaccharide biosynthesis were upregulated in the HE0277 cells. The extracellular polysaccharide released into the culture medium of the HE0277 cells was as much as 3.2-fold more than that released by the control cells. This strongly suggests that the group 3 sigma factor gene sigJ is fundamental and conducive to desiccation tolerance in these cyanobacteria.
Yoshimura
Hidehisa
H
Center of Systems Biology and Ecology, Faculty of Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 274-8510, Japan. h-yoshimura@sci.toho-u.ac.jp
Okamoto
Shinobu
S
Tsumuraya
Yoichi
Y
Ohmori
Masayuki
M
D000064:Acclimatization / Q000235:genetics; D017033:Anabaena / Q000235:genetics* / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D004190:Disasters; D017753:Ecosystem; D005798:Genes, Bacterial; D046937:Nostoc / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D011135:Polysaccharides, Bacterial / Q000096:biosynthesis*; D012808:Sigma Factor / Q000235:genetics*; D014867:Water / Q000378:metabolism
D001426:Bacterial Proteins; D017931:DNA Primers; D004269:DNA, Bacterial; D011135:Polysaccharides, Bacterial; D012808:Sigma Factor; D014867:Water