Figure 4.

Investigations of the geranylgeranylation potential of Ydj1p. (A) The indicated Ydj1p Cxxx variants were assessed for their ability to restore thermotolerance to a ydj1∆ ram1∆ (yWS2542) background as described for Figure 1, except that the 40° incubation was ∼80 hr without recovery. (B) Lysates for gel-shift assays were prepared from mid-log cultures incubated at either 40° or 25° (the latter are marked with an asterisk). The strain backgrounds used were ydj1∆ RAM1 (+; yWS2544) and ydj1∆ ram1∆ (−; yWS2542). Of note, the ram1∆ cultures were slow growing relative to RAM1 cultures at 40°, taking 36 or more hours instead of 18–24 hr to achieve the same cell density. Unmodified Ydj1p (open triangle) migrates at a larger apparent kDa than prenylated Ydj1p (closed triangle).