STE11 is a protein kinase required for cell-type-specific transcription and signal transduction in yeast.

The STE11 gene of Saccharomyces cerevisiae is one of several genes required for mating between two haploid cell types of this yeast. Its product is required for response to a signal that causes arrest of the mitotic cell cycle in the G1 phase and induction of mating-type-specific genes. The nucleotide sequence of the STE11 gene was determined. The predicted amino acid sequence shows homology to the protein kinase family. We demonstrate that the STE11 product has kinase catalytic activity and that this activity is required for its in vivo functions.