Table IV.

Effect of CHI, BFA, and staurosporine on protein biosynthesis and secretion in tobacco cells

ProcedureControlsTreated Cells
10 μm CHI25 μm BFA1 μm Staurosporine
% of controls
11002.7  ± 0.399  ± 7127  ± 10
(15.9  ± 2.6 KBq)
2100 93  ± 664  ± 494  ± 6
(0.27  ± 0.08 KBq)3-a

Protein labeling was carried out by incubating cells (100 mg mL−1) with 3 to 8 nm [3H]Leu for 10 min and stopped by addition of 1 mm unlabeled Leu. Inhibitors were added 20 min prior to (procedure 1) or immediately after (procedure 2) the pulse-chase sequence and were maintained in contact with cells for 30 min in both procedures. Four series of experiments were run independently, with cells treated by inhibitors and processed in parallel according to both procedures. Data, means ± se of values obtained in the four experiments, represent the radioactivity incorporated into total (procedure 1) and secreted (procedure 2) proteins prepared from treated cells.

    • F3-a Total incorporated [3H]Leu: 11.0 ± 2.3 KBq.