Our results provide clear evidence that encystation stimuli alter plasma membrane lipid ordering, activate AC2-dependent intracellular cAMP elevation accompanied with dissociation of PKAr and PKAc, and this increase of intracellular cAMP upregulates MYB2, CWPs, and four enzymes in the GalNAc pathway to enable successful cyst production. Here, ADCY2 is linked to cyst.