During the mating process of yeast cells, two Ca2+ influx pathways become activated. The resulting elevation of cytosolic free Ca2+ activates downstream signaling factors that promote long term survival of unmated cells. Fig1 is a regulator of the low affinity Ca2+ influx system (LACS) [1], and is also required for efficient membrane fusion during yeast mating [2].

1: Fig1p facilitates Ca2+ influx and cell fusion during mating of Saccharomyces cerevisiae. Muller EM, Mackin NA, Erdman SE, Cunningham KW; J Biol Chem. 2003;278:38461-38469. PMID:12878605

2: The plasma membrane proteins Prm1 and Fig1 ascertain fidelity of membrane fusion during yeast mating. Aguilar PS, Engel A, Walter P; Mol Biol Cell. 2007;18:547-556. PMID:17151357