Figure 4.
PAPK Displays Substrate Specificity for Viral and Endogenous Non-Cell-Autonomous Proteins.
Substrate specificity of PAPK tested using two plant NCAPs, KN1 and LFY, and two viral MPs, BC1 and BV1. TMV MP and TMV MPΔC11 were included as controls. Each in vitro phosphorylation assay contained 5 μL of heparin column-purified PAPK fraction and 1 μg of substrate protein in a 50-μL reaction volume. Note that LFY, TMV MP, and BC1 served as specific substrates for PAPK, whereas KN1 and BV1 were not phosphorylated.