High-level expression of human superoxide dismutase in the cyanobacterium Anacystis nidulans 6301.

Abstract

A chemically synthesized gene encoding human CuZn superoxide disute (hSOD) was loned into the shuttle vector pBAX18R and expressed in Anacysts ins 6301 (Synechococcus sp. strain PCC 6301) under the control of a ribulose-1,5-bisphosphate carboxylase/oxygenase gene (rbc) promoter derived from A. nidulans 6301. The sequences immediately upstream from the hSOD coding region and the distances between the ribosomal binding site and ATG initiation codon strongly affected the expression of the hSOD gene in A. nidulans cells. Optimal expression of hSOD was obtained with the expression vector pBAXSOD8-I, which contained a GGAGAG sequence. In defined conditions, irradiation with light increased hSOD enzyme activity in the transformants >18-fold and the level of the hSOD protein reached a value of about 3% of the total soluble protein. The trnsformants that expressed hSOD acquired the ability to extenuate photooxidative damage induced by methyl viologen.

Nitrogen status dependent oxidative stress tolerance conferred by overexpression of MnSOD and FeSOD proteins in Anabaena sp. strain PCC7120

“…5). The requirement of SOD for oxidative stress tolerance has earlier been demonstrated for the adiazotrophic cyanobacterium, Anacystis nidulans, by overexpressing heterologous SOD proteins (Gruber et al 1990;Takeshima et al 1994). In Anabaena 7120, the protection against oxidative stress conferred by the individual sod genes was strictly dependent on the nitrogen status of the cells.…”

“…strain PCC7942, sodB mutation resulted in damage to the photosynthetic machinery at PS I in the presence of methyl viologen (MV, 50 lM) (Herbert et al 1992), somewhat unexpected for a cytosolic enzyme, and a much higher sensitivity to MV (0.5 lM) induced oxidative stress (Thomas et al 1998). The oxidative stress tolerance of another adiazotrophic cyanobacterium, Anacystis nidulans was found to be enhanced upon overexpression of E. coli MnSOD (Gruber et al 1990) or human Cu/Zn-SOD (Takeshima et al 1994). An increase in sodB transcript has been observed during nitrogen-deficiency in Anabaena 7120 (Liu et al 2000), suggesting its possible involvement in protection of nitrogenase.…”

Discovery of a super-strong promoter enables efficient production of heterologous proteins in cyanobacteria

“…The human CuZn superoxide dismutase was expressed at a level of 3% of total soluble protein in the cyanobacterium Anacystis nidulans 63016. This expression level was achieved by using a native strong promoter, P rbc343 , and an optimized SD sequence.…”

Plant Responses to Metal Stress

“…One class of SOD can complement the deletion mutations of other classes of SODs within and between species, families, and even kingdoms (Purdy and Park, 1994;Takeshima et al, 1994;Myouga et al, 2008). One class of SOD can complement the deletion mutations of other classes of SODs within and between species, families, and even kingdoms (Purdy and Park, 1994;Takeshima et al, 1994;Myouga et al, 2008).…”