Yeast decide to enter the cell cycle based on the history of pheromone exposure
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Compartmentalization enables transmission of memory from mother to daughter
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Intergenerational memory of pheromone exposure is stored as cytoplasmic Far1
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Anchoring of cytoplasmic Far1 by Cdc24 is required for intergenerational memory
Summary
Cells make accurate decisions in the face of molecular noise and environmental fluctuations by relying not only on present pathway activity, but also on their memory of past signaling dynamics. Once a decision is made, cellular transitions are often rapid and switch-like due to positive feedback loops in the regulatory network. While positive feedback loops are good at promoting switch-like transitions, they are not expected to retain information to inform subsequent decisions. However, this expectation is based on our current understanding of network motifs that accounts for temporal, but not spatial, dynamics. Here, we show how spatial organization of the feedback-driven yeast G1/S switch enables the transmission of memory of past pheromone exposure across this transition. We expect this to be one of many examples where the exquisite spatial organization of the eukaryotic cell enables previously well-characterized network motifs to perform new and unexpected signal processing functions.
