Mutations within the first LSGGQ motif of Ste6p cause defects in a-factor transport and mating in Saccharomyces cerevisiae.

摘要: Mating between the two haploid cell types (a and alpha) of yeast Saccharomyces cerevisiae depends upon efficient secretion delivery a- alpha-factor pheromones to their respective target cells. However, a quantitative correlation level transported a-factor mating efficiency has never been determined. a-Factor is by Ste6p, member ATP-binding cassette (ABC) family transporter proteins. In this study, several missense mutations were introduced in or near conserved LSGGQ motif within first nucleotide-binding domain Ste6p. Quantitation extracellular levels indicated that these caused broad range transport defects, those directly most severe defects. Overall, we observed strong strains, consistent with role Ste6p as transporter. The did not cause either significant alteration steady-state detectable change its subcellular localization. Thus, it appears interfere ability out MATa cell. possible involvement function conservation sequence throughout ABC superfamily.