Figure 5.

The CT region of BoBAK1 is a positive regulator and AtBAK1 is a negative regulator of recombinant BAK1 transphosphorylation activity. (A) Kinase activity of wild-type and CT region-deletion BAK1 from B. oleracea, A. thaliana, and R. sativus. Immunoblots were probed with pY or pThr, and anti-FLAG tag antibodies; (B) Alignment of amino acid sequences of BAK1 CT regions from four plant species (R. sativus, Brassica rapa, B. oleracea, and A. thaliana); the sequences from the first three species are very similar and differ greatly from AtBAK1; (C) Schematic representation of the Flag-BoBAK1 truncated CD used in these experiments. Residue numbers at the domain interfaces are shown. Phospho-amino acid signals are normalized against the amount of recombinant protein, determined by cross-reaction with anti-FLAG antibodies. JM: juxtamembrane domain; KD: kinase domain.