Figure 5.

Association of MPK4 with the MT Surface.

Analysis of MT pellets from Arabidopsis extracts supplemented with exogenous bovine brain MTs (10 μM tubulin). Lane 1 shows the occurrence of MPK4 in the original supernatant (see Methods). Lanes 2 and 3 show the occurrence of MPK4 in the final MT pellets following the last glycerol cushion precipitation. In lane 3, the reaction mixture was supplemented with 10 μM 6×His-tagged MAP65-1. No significant difference can be detected in the efficiency of MPK4 coprecipitation in the presence or absence of MAP65-1. The bottom two rows show the same experiment in the absence of the glycerol cushion, which greatly enriches the amount of tubulin (bottom panel).