Gene Expression Enhancement due to Plasmid Maintenance

DÍAZ RICCI, JUAN C.; BODE, J.; RHEE, J.L.; SCHÜGERL, K

JOURNAL OF BACTERIOLOGY

AMER SOC MICROBIOLOGY

Lugar: Washington; Año: 1995 vol. 177 p. 6684 - 6687

0021-9193

Analysis of the chromosomic b-galactosidase activity in strains of Escherichia coli with and without plasmids indicated that plasmid maintenanceenhances gene expression. Cyclic AMP (cAMP) determinations confirmed that the gene enhancement observedin strains carrying plasmids was due to a small increase in the intracellular concentrationof cAMP. Also, cells carrying plasmids displayed higher specific glucose uptakerates than did cells without plasmids. The increases in the expression of b-galactosidase and the glucoseuptake rate suggest a cAMP-mediated release of the glucose effect due toplasmid maintenance. Our results suggested that this effect is independent ofthe host and type and number of plasmids.