The whiA (NCgl1527) gene from Corynebacterium glutamicum plays a crucial role during cell growth, and WhiA is recognized as the transcription factor for genes involved in cell division. In this study, we assessed the regulatory role of the gene in cell physiology. Transcription of the gene was specifically downregulated by the thiol-specific oxidant, diamide, and by heat stress. Cells exposed to diamide showed decreased transcription of genes involved in cell division and these effects were more profound in ΔwhiA cells. In addition, the ΔwhiA cells showed sensitivity to thiol-specific oxidants, DNA-damaging agents, and high temperature. Further, downregulation of sigH (NCgl0733), the central regulator in stress responses, along with master regulatory genes in cell metabolism, was observed in the ΔwhiA strain. Moreover, the amount of cAMP in the ΔwhiA cells in the early stationary phase was only at 30% level of that for the wild-type strain. Collectively, our data indicate that the role of whiA is to downregulate genes associated with cell division in response to heat or thiol-specific oxidative stress, and may suggest a role for the gene in downshifting cell metabolism by downregulating global regulatory genes when growth condition is not optimal for cells.

谷氨酸棒杆菌的whiA（NCgl1527）基因在细胞生长过程中起着至关重要的作用，WhiA被认为是参与细胞分裂的基因的转录因子。在这项研究中，我们评估了该基因在细胞生理中的调控作用。该基因的转录被巯基特异性氧化剂二酰胺和热应激特异性下调。暴露于二酰胺的细胞显示参与细胞分裂的基因转录降低，这些作用在ΔwhiA细胞中更为明显。另外，ΔwhiA细胞显示出对硫醇特异性氧化剂，DNA损伤剂和高温的敏感性。此外，sigH的下调（NCgl0733）是在ΔwhiA菌株中观察到了应激反应的中央调控因子，以及细胞代谢中的主要调控基因。而且，在早期静止期的ΔwhiA细胞中cAMP的量仅为野生型菌株的cAMP量的30％。总体而言，我们的数据表明，whiA的作用是下调与细胞分裂相关的基因以响应热或硫醇特异性氧化应激，并可能通过在生长条件良好时下调全局调节基因来暗示该基因在下调细胞代谢中的作用。对于细胞而言并非最佳。