Conjugation in the fission yeast Schizosaccharomyces pombe is controlled by the action of mating pheromones. Here I describe the isolation and characterization of M‐factor, the pheromone released by M‐type cells. M‐factor is a nanopeptide in which the carboxy‐terminal cysteine residue is carboxy‐methylated and S‐alkylated, probably with a farnesyl residue: Tyr‐Thr‐Pro‐Lys‐Val‐Pro‐Tyr‐Met‐Cys(S‐farnesyl)‐OCH3. Evidence for this structure was obtained by amino acid analysis, mass spectrometry and tandem mass spectrometry of the native M‐factor. Two genes encoding the M‐factor were also identified and characterized. It appears that M‐factor is synthesized as a larger precursor which is post‐translationally cleaved and modified to yield the active pheromone. The proposed modifications are consistent with mechanisms known to exist in other yeast and higher eukaryotes.

Authors and Affiliations

1. School of Biochemistry, University of Birmingham, UK

   J. Davey

Copyright: European Molecular Biology Organization

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