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Pheromone Response (pheromone + response)
Selected AbstractsPhospholipase D1 is required for efficient mating projection formation in Saccharomyces cerevisiaeFEMS YEAST RESEARCH, Issue 3 2001Michelle L. Hairfield Abstract Phospholipase D1 (PLD1) is an important enzyme involved in lipid signal transduction in eukaryotes. A role for PLD1 in signaling in Saccharomyces cerevisiae was examined. Pheromone response in yeast is controlled by a well-characterized protein kinase cascade. Loss of PLD1 activity was found to impair pheromone-induced changes in cellular morphology that result in formation of mating projections. The rate at which projections appeared following pheromone treatment was delayed, suggesting that PLD1 facilitates the execution of a rate-limiting step in morphogenesis. Mutants were found to be less sensitive to pheromone, again arguing that PLD1 is acting at a rate-limiting step. The fact that morphogenesis is most dramatically affected indicates that PLD1 functions primarily in the morphogenic branch of the pheromone response pathway. [source] The immunosuppressive drug leflunomide affects mating-pheromone response and sporulation by different mechanisms in Saccharomyces cerevisiaeFEMS MICROBIOLOGY LETTERS, Issue 1 2000Hiro-aki Fujimura Abstract Leflunomide (LFM) is a novel anti-inflammatory and immunosuppressive drug, and inhibits the growth of cytokine-stimulated lymphoid cells in vitro. The effect of LFM on haploid and diploid cells of Saccharomyces cerevisiae was investigated to elucidate the molecular mechanism of action of the drug. Using a halo assay, LFM was shown to enhance the cell cycle arrest of haploid cells induced by mating pheromone ,-factor. LFM also inhibited sporulation of diploid cells completely. S. cerevisiae genes which were cloned to suppress the anti-proliferative effect when present in increased copy number were introduced and examined for their activity to suppress the effect of LFM. Out of them, MLF4/SSH4, was found to suppress the sporulation-inhibitory effect of LFM. However, MLF4 failed to suppress the enhancing effect of LFM on pheromone response. Thus, LFM is suggested to act on haploid and diploid cells by different mechanisms. [source] Why does Candida albicans switch?FEMS YEAST RESEARCH, Issue 7 2009David R. Soll Abstract White,opaque switching in Candida albicans was first discovered in 1987. Fifteen years later, and three years after the discovery of the mating system, it was demonstrated that the switch from white to opaque was an essential step in the mating process. But this latter discovery did not reveal why C. albicans had this requirement, when Saccharomyces cerevisiae and other hemiascomycetes did not. The discovery that mating-competent opaque cells signaled mating-incompetent white cells, through the release of pheromones, to become adhesive and form biofilms provided a clue to this fundamental question. Opaque cells appeared to signal white cells to form biofilms that facilitated mating by protecting the fragile gradients of the pheromone that directed chemotropism, a process necessary for fusion. Here, we explore the discoveries and observations that have led to this hypothesis, and the ancillary questions that have risen that are related to the regulation of the unique pheromone response, the evolution of this response and the relationship between pheromone-enhanced white cell biofilms and ,asexual' biofilms formed by a/, cells. This discussion, therefore, focuses on a unique and complex component of the basic biology of C. albicans that relates switching, mating and pathogenesis. [source] Seasonal pheromone response by Ips pini in northern Arizona and western Montana, U.S.A.AGRICULTURAL AND FOREST ENTOMOLOGY, Issue 3 2008Brytten E. Steed Abstract 1,Populations of Ips pini (Say) in northern Arizona and western Montana, U.S.A., were studied to determine regional pheromone response and to evaluate seasonal shifts in that response. A range of enantiomeric blends of the attractant ipsdienol, alone and in the presence of the synergist lanierone, were tested during spring and summer seasons over several years. 2,Both populations were most attracted to high levels of (R)-(,)-ipsdienol, and lanierone was highly synergistic. 3,A significant seasonal shift in pheromone response between spring and summer seasons was found in both regions in both years. Shifts resulted in a more specific preference for the pheromone treatment of 97% (R)-(,)-ipsdienol with lanierone. 4,Several coleopteran insect associates of I. pini also displayed responses to the ipsdienol and lanierone treatments. Temnochila chlorodia (Mannerheim) (Trogositidae), Enoclerus sphegeus (F.) (Cleridae) and, to a limited extent, Lasconotus laqueatus (LeConte) (Colydiidae) were attracted to higher proportions of (R)-(,)-ipsdienol with no apparent reaction to the presence of lanierone. Orthotomicus latidens (LeConte) (Curculionidae: Scolytinae) was strongly attracted to (S)-(+)-ipsdienol with Enoclerus lecontei (Wolcott) (Cleridae), Pityogenes carinulatus (LeConte) (Curculionidae: Scolytinae) and Hylurgops porosus (LeConte) (Curculionidae: Scolytinae) demonstrating some preferences for the (S)-(+)-enantiomer. However, lanierone was synergistic for E. lecontei and P. carinulatus, inhibitory for O. latidens, and produced no significant reaction for H. porosus. Elacatis sp. (Salpingidae, previously Othniidae) was attracted to the presence of ipsdienol but displayed no preference to the enantiomeric ratios of ipsdienol or the presence of lanierone. [source] | ||||||||||