FIGURE 2: Crosstalk between cAMP-PKA and CWI pathway in response to heat stress. (A) Damage in the cell wall is sensed via Wsc1-3, Mtl1 and Mid2 sensors that trigger the CWI cascade conformed by Bck1, Mkk1/Mkk2, and Slt2 through Rho1 and the activation of Pkc1. (B) Upon heat stress, CWI pathway is activated by a different mechanism, regulating the kinases Mkk1,2 and Stl2 rather than Rho1 or Pkc1. Heat stress would be acting as a lateral input rather than operating in a linear “top-down” manner. (C) Tpk1 expression regulation during heat stress. Tpk1 upregulation depends on the Wsc3 membrane sensor Mkk1 and the transcription factor Swi4.