Figure 5.

PKA phosphorylates Nem1 and Spo7 synthetic peptides. PKA activity was measured with a 100 μm concentration of the indicated Nem1 (A) or Spo7 (B) peptides using 100 μm [γ-³²P]ATP. The enzyme reaction was terminated by spotting the mixture onto P81 phosphocellulose paper, which was then washed with 75 mm phosphoric acid and subjected to scintillation counting. The numbers to the left and right of the Nem1 (A) or Spo7 (B) peptides represent the position of the sequence in the respective proteins. The boldface red residues within the Nem1 peptides designate the serine-to-alanine substitutions in the sequence. The boldface red residues within the Spo7 peptide were identified as phosphorylation sites by MS. The data are the averages of three experiments ± S.D. (error bars).