HOG on the promoter: regulation of the osmotic stress response.

Members of the mitogen-activated protein (MAP) kinase family regulate transcription through phosphorylation of specific transcription factors. New studies indicate that this process may be more complex than previously anticipated. The yeast Hog1 protein kinase (a homolog of the mammalian p38 MAP kinase) interacts with transcription factors and perhaps with the general transcription machinery at target promoters. Chellappan discusses the recent results and their implications for understanding control of transcription by stress-activated MAP kinases.