... Lett. 11 7, 12 1 13 0.3. Stark, M.J. (19 96) Yeast protein serine/threonine phosphatases:multiple roles and diverse regulation. Yeast 12 , 16 47 16 75.4. Posas, F., Casamayor, A., Morral, N. & Arin˜o, ... 0 819 3, Ba rcelona, Spain.E-mail: Joaquin.Arino@uab.esAbbreviations: MAP kinase, mitogen activated protein kinase; TOR,target of rapamycin; PP1, type 1 protein phosphatase; PP2A, type 2A protein ... Erez,O.&Kahana,C.(20 01) Screeningformodulatorsofsper-mine t olerance identifies S ky1, the SR protein kinase of Saccharo-myces cerevisiae, as a regulator of p olyamine transport and ionhomeostasis. Mol. Cell. Biol. 21, 17 5 18 4. 16 . Ferrando,...