FIG 3.

Trypanosomal adenylate cyclases are catalytically active. A temperature-sensitive Saccharomyces cerevisiae adenylate cyclase mutant (cyr1-2) was transformed with a yeast expression vector containing either the S. cerevisiae wild-type adenylate cyclase (CYR1) or the gene for T. brucei ACP1, ACP2, ACP4, or ACP5 (TbACP1, TbACP2, TbACP4, and TbACP5, respectively). An empty vector was transformed as a control, and yeast viability was assessed at the permissive (22°C) and restrictive (35°C) temperatures.