Fig. 6.
Phosphorylation of the ACA8 N-terminus by different isoforms of CDPK. The N-terminus of WT ACA8 (6His-1M-I116) was phosphorylated with Ca2+-independent mutants of A. thaliana CPK1 or CPK16 as described in the Materials and methods. Samples were solubilized and aliquots corresponding to 3 μg of 6His-1M-I116 were subjected to SDS–PAGE, blotting, and autoradiography (lane 1, 6His-1M-I116; lane 2, CPK1; lane 3, 6His-1M-I116 plus CPK1; lane 4, CPK16; lane 5, 6His-1M-I116 plus CPK16). Results are from one experiment representative of four.