Prion-like RNA binding protein that modulates mRNA stability; regulates sister chromatid cohesion, stress-response genes, critical cell size and ploidy; controls CLN3 mRNA stability and translational efficiency; colocalizes with P-bodies/stress granules to regulate target mRNAs; Whi3p condensates and P-bodies regulate cell fate, promoting senescence; self-templating mnemon that forms inactive super-assemblies, preventing G1 arrest in mother cells after unsuccessful mating and causing sterility