Degradation of a-factor by a Saccharomyces cerevisiae alpha-mating-type-specific endopeptidase: evidence for a role in recovery of cells from G1 arrest.
Mating response between opposite mating types of Saccharomyces cerevisiae is dependent upon alpha factor, a tridecapeptide, and a-factor, an isoprenylated, methyl esterified dodecapeptide whose interaction with the alpha target cell has not been characterized. We report on the first biochemical and physiological evidence of an alpha-mating-type-specific a-factor-degrading activity. Radioiodinated a-factor was used to identify the a-factor-degrading activity, which is cell associated, endoproteolytic, and not required for response to pheromone. a-factor degradation was not energy dependent, nor did it require pheromone internalization or interaction with its receptor. Phenylmethylsulfonyl fluoride and tosyl-L-arginyl-methyl ester inhibited degradation of a-factor and increased the time required by alpha cells to recover from a-factor-induced growth arrest and morphological alteration, providing evidence that a-factor degradation plays a role in the recovery of alpha cells from the pheromone response.
Marcus
S
S
Department of Microbiology, University of Tennessee, Knoxville 37996.
Xue
C B
CB
Naider
F
F
Becker
J M
JM
D000595:Amino Acid Sequence; D010450:Endopeptidases / Q000378:metabolism*; D016193:G1 Phase; D007700:Kinetics; D000072235:Mating Factor; D008969:Molecular Sequence Data; D010455:Peptides / Q000302:isolation & purification / Q000378:metabolism*; D010675:Pheromones / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
D010455:Peptides; D010675:Pheromones; D000072235:Mating Factor; D010450:Endopeptidases