Transient increase of Ca2+ uptake as a signal for mating pheromone-induced differentiation in the heterobasidiomycetous yeast Rhodosporidium toruloides

Abstract

The role of Ca2+ for the signaling of rhodotorucine A, a mating pheromone of Rhodosporidium toruloides, was investigated. The efficiency with which the target cells responded to the mating pheromone was dependent on the Ca2+ concentration in the medium. The pheromone induced a very rapid and transient increase of Ca2+ uptake in the recipient cell. We concluded that the transient increase in the intracellular Ca2+ concentration could play an essential role in the control of differentiation by the pheromone.

Inhibition of membrane Ca2+-ATPase of Saccharomyces cerevisiae by mating pheromone α-factor in vitro

“…We have previously demonstrated that one of the earliest physiological effects of the mating pheromones, in both Rhodosporidium toruloides and S. cerevisiae , is a very rapid and transient uptake of Ca 2+ from the medium. The change appears to be involved in mating pheromone signal transduction (Miyakawa et al ., 1985, 1986; Tachikawa et al ., 1987).…”

“…Also, from the studies with pheromone analogues, it was found that the inhibition correlated highly with the biological activity of the mating pheromone (Miyakawa et al ., 1987). The inhibition of Ca 2+ -ATPase could be responsible for the pheromone-induced intracellular Ca 2+ increase (Miyakawa et al ., 1985, 1986). In the present study, we report the effect of mating pheromone α-factor on the membrane Ca 2+ -ATPase of S. cerevisiae .…”

Superoxide dismutase activity and glutathione concentration during the calcium‐induced differentiation of Physarum polycephalum microplasmodia

“…The molecular mechanisms involved in calcium-regulated cell state transitions remains to be elucidated. Calcium can alter some cell surface properties and can modulate the activity of calcium requiring enzymes in the plasma membrane (Miyakawa et al, 1985;Tupper et al, 1978). The intracellular effects of calcium may be direct interaction between Ca2+ ions and enzymes or may result indirectly via a calcium-calmodulin complex which activates enzyme systems (Cheung et al, 1978).…”

Fungal lipopeptide mating pheromones: a model system for the study of protein prenylation.

“…In addition to the previously described intracellular protease involved in CAAX processing, degradative activities have been identified in R. toruloides and S. cerevisiae that specifically act upon the farnesylated peptides of these fungi and affect their bioactivity. Endoproteolytic cleavage of rhodotorucine A by an R. toruloides a-mating-type-specific peptidase appears to be involved in signal transmission and is possibly associated with the stimulation of a membrane-bound calcium ATPase (116,117). In contrast, the a-factorase of S. cerevisiae appears to cleave the farnesylated a-factor pheromone, rendering it inactive, thus allowing for cellular recovery from pheromone arrest (106).…”