Adaptor Proteins, Signal Transducing Article Binding Sites CLN1 protein, S cerevisiae CLN2 protein, S cerevisiae Cdc28 Cell Cycle Checkpoints Cell Membrane Cks1 Cln2 Cyclin-Dependent Kinases Cyclins FUS3 protein, S cerevisiae G protein G1 phase cell cycle checkpoint Kinetics MAPK signaling Mitogen-Activated Protein Kinases Phosphorylation Protein Binding STE5 protein, S cerevisiae Saccharomyces cerevisiae Saccharomyces cerevisiae Proteins Saccharomyces cerevisiae protein Signal Transduction Ste4 Substrate Specificity binding site cell cycle S phase cell cycle checkpoint