Fig. 7.

A, B Involvement of the cAMP pathway in osmotic stress response. A The cAMP pathway is required for viability of S. pombe cells in high osmolarity medium. Wild-type, cyr1Δ, gpa2Δ, git3Δ, pka1Δ, and cgs1Δ cells were streaked onto YEAU (left) or YEAU containing 1.2 M KCl (right) and incubated at 30°C for 2 and 4 days, respectively, prior to photographing the plates. Wild-type and cgs1Δ cells grew on YEAU+KCl, whereas the other strains were either inviable (cyr1Δ, gpa2Δ, and pka1Δ) or strongly growth impaired (git3Δ) on the same medium. B Adenylate cyclase is required for full induction of gpd1 expression in response to osmotic stress. Wild-type and cyr1Δ S. pombe cultures were grown in EMM to mid-log phase, then mixed with equal volumes of either EMM or EMM containing 3 M KCl (for a final concentration of 1.5 M KCl) and incubated for 90 min, prior to isolation of RNA and subsequent Northern blot analyses for expression of gpd1. Membranes were stripped and reprobed with the leu1 gene as a standard for RNA loading