Figure 4.

Characterization of the membrane-bound CDPK by immunoblot and in-gel kinase assay. Partially purified CDPK prepared from shoots from control (27°C) and cold-treated (12°C) plants was analyzed by immunostaining (A) and in-gel kinase activity (B). A, Samples were electrophoresed in 8% (w/v) SDS-polyacrylamide gels, electroblotted to nitrocellulose, and probed with a polyclonal antibody against the calmodulin-like domain of soybean CDPK. B, Samples were electrophoresed in 8% (w/v) SDS-polyacrilamide gel containing Histone III-S and incubated with [³²P]ATP as described in “Materials and Methods.” The prestained molecular mass markers used were: myosin (202 kD), β-galactosidase (133 kD), bovine serum albumin (71 kD), carbonic anhydrase (41.8 kD), soybean trypsin inhibitor (30.6 kD), lysozyme (17.8 kD), and aprotinin (6.9 kD)