Figure 3.
Lck synthesized in the absence of Hsp90 activity is rapidly degraded. SupT1 cells were labeled with [35S]methionine/cysteine for 5 min and chased in an excess of unlabeled amino acids for the indicated times. Cells were either not treated (−; A) or treated as described in MATERIALS AND METHODS with 5 μM geldanamycin only (GA; B), with both 5 μM geldanamycin and 50 μM LLnL (GA + LLnL; C), with 10 μM radicicol only (Rad; D), or with both 10 μM radicicol and 10 μM lactacystin (Rad + Lac; E). Lck was immunoprecipitated with anti-Lck serum. In addition to Lck, coimmunoprecipitated CD4 and a background band (★) were detected.