FIGURE 3.

Effects of growth phases and global regulatory proteins on the gbpA expression. Upper panel, growth kinetics of V. vulnificus and growth phase-dependent expression of gbpA. A, growth of the wild type culture in LBS was monitored spectrophotometrically at 600 nm (A₆₀₀), and total RNAs were isolated from the cells harvested at different growth phases (from left, at A₆₀₀ of 0.5, 1.0, 1.5, 2.0, and 2.5) as indicated by arrows. B, gbpA mRNA levels were determined by qRT-PCR analyses, and the gbpA mRNA level in the cells grown to an A₆₀₀ of 0.5 was set as 1. Error bars represent the S.D. *, p < 0.05, and **, p < 0.005 relative to the cells grown to an A₆₀₀ of 0.5. Lower panel, expression of gbpA in V. vulnificus with different genetic backgrounds. Samples were harvested from the cultures of the wild type (WT) and isogenic mutants grown aerobically to an A₆₀₀ of 0.5 and analyzed to determine the gbpA mRNA and GbpA protein levels. C and E, gbpA mRNA levels were determined by qRT-PCR analyses, and the gbpA mRNA level in the wild type was set as 1. **, p < 0.005 relative to the wild type. D and F, protein samples were resolved by SDS-PAGE, and GbpA was detected by Western blotting using the rabbit anti-V. vulnificus GbpA serum. (pJK1113), wild type; iscR (pJK1113), iscR mutant; smcR (pJK1113), smcR mutant; crp (pJK1113), crp mutant; iscR (pKK1403), crp (pKK1404), and smcR (pKK1405), complemented strains.