Cells of S. cerevisiae (Saccharomyces cerevisiae) produce one of two Mating pheromones, A-Factor and MF-Alpha (Mating Factor-Alpha). Mating pheromones bind to their receptors like Ste2 (Sterile/Alpha-Factor Pheromone Receptor) and Ste3 (Pheromone A-Factor Receptor), which leads to G-protein activation and induces the dissociation of the heterotrimeric G-protein subunits designated Gpa1 (Alpha-subunit), Ste4 (Beta-subunit), and Ste18 (Gamma-subunit). These pheromones prepare cells for mating by inducing cell cycle arrest in G1 and also raises the levels of intracellular Ca2+ (Calcium) and induce activation of Calcineurin Complex (or Calcium-Dependent Protein Serine/Threonine Phosphatase Complex). The S. cerevisiae Calcineurin Complex consists of four proteins: Two Calcineurin-A subunits, CNA1 (Calcineurin Subunit-A/Type-2B protein Serine/Threonine Phosphatase Catalytic Subunit-A1) and CNA2 (Calcineurin Subunit-A/Type-2B Protein Serine/Threonine Phosphatase); a Calcineurin Regulatory B-subunit [...]