Figure 5.

Effect of heat shock and canavanine treatments on PR500 accumulation. Gel filtrations were conducted as in Figure 4 and selected fractions were analyzed. (A) Gel filtration profiles of Rpn6 from seedlings grown under indicated conditions. The positions of PR500 and 19S RP are indicated on the top. Molecular size markers are indicated at the bottom. “−ATP, protein extraction and gel filtration were conducted in buffers without ATP. +ATP, protein extraction and gel filtration were conducted in buffers with 10 and 2 mM ATP each. (B) The protein levels of Rpn6 and Rpt5 in the controls and stress-treated Arabidopsis seedlings. Lanes 1 and 3, the protein extracts from the control and heat shock-treated (42°C for 3 h) seedlings. Lanes 2 and 4, the protein extracts from the seedlings grown in the absence or presence of 4 mM canavanine. The tubulin antibodies were used as a control for equal loading.