The CpxA/CpxR two-component system mediates regulation of cold growth.

Introduction: To survive in various hostile environments, two-component system is an adaptive mechanism for diverse bacteria. Activity of the CpxA/CpxR two-component system contributes to coping with different stimuli, such as pH, osmotic and heat stress.

Methods: However, the role of the CpxA/CpxR system in cold resistance is little-known. In this study, we showed that CpxA/CpxRwas critical for growth under cold stress.

Results: -Galactosidaseanalysis showed that CpxA/CpxR positively regulated the predicted cold stress gene . The mutant for cold stress gene was impaired in the optimal growth of under cold stress. Furthermore, electrophoretic mobility shift assays demonstrated that CpxR-P could directly regulate the transcription of the cold stress gene .

Discussion: These results presented in this study illustrated that the CpxA/CpxR system plays an important role in cold resistance by upregulating expression of . The data give new insights into how survives in cold stress.