Analysis of random PCR-originated mutants of the yeast Ste2 and Ste3 receptors.

The G protein-coupled receptors Ste2 and Ste3 bind α- and a-factor, respectively, in Saccharomyces cerevisiae. These receptors share a similar conformation, with seven transmembrane segments, three intracellular loops, a C-terminus tail, and three extracellular loops. However, the amino acid sequences of these two receptors bear no resemblance to each other.

Yeast pheromone receptor genes STE2 and STE3 are differently regulated at the transcription and polyadenylation level.

The orderly expression of specific genes is the basis for cell differentiation. Saccharomyces cerevisiae has two haploid mating types, a and α cells, in which the mating-specific genes are differentially expressed. When a and α cells are committed to mate, their growth is arrested.

Cis- and trans-splicing of mRNAs mediated by tRNA sequences in eukaryotic cells.

The formation of chimeric mRNAs is a strategy used by human cells to increase the complexity of their proteome, as revealed by the ENCODE project. Here, we use Saccharomyces cerevisiae to show a way by which trans-spliced mRNAs can be generated. We demonstrate that a pretRNA inserted into a premRNA context directs the splicing reaction precisely to the sites of the tRNA intron.

A pre-tRNA carrying intron features typical of Archaea is spliced in yeast.

Archaeal pre-tRNAs are characterized by the presence of the bulge-helix-bulge (BHB) structure in the intron stem-and-loop region. A chimeric pre-tRNA was constructed bearing an intron of the archaeal type and the mature domain of the Saccharomyces cerevisiae suppressor SUP4 tRNA(Tyr). This pre-tRNA(ArchEuka) is correctly cleaved in several cell-free extracts and by purified splicing endonucleases.