Farnesylation of Pex19p. Size comparison of in vitro transcription/translation product of normal and mutated PEX19 cDNA and Pex19p of CHO cells. In vitro transcription/translation product of HsPEX19 and CHO-K1 cell-lysates were subjected to SDS/PAGE. Immunodetection was done for lane 1, as in Fig. 3B, by using anti-Pex19p antibody; radioactive bands were detected by a FujiX BAS1500 Bio-Imaging Analyzer at exposures for 16 h (lanes 2–4, 7, and 8) and 72 h (lanes 5 and 6). Lanes: 1, 40 μg of CHO-K1 cell-lysates; 2, in vitro transcription/translation product (1 μl) of HsPEX19 in the presence of [35S]methionine and [35S]cysteine as label; 3 and 4, immunoprecipitation of 35S-Pex19p (3.5 μl) was done with preimmune and anti-Pex19p immune sera, respectively; 5 and 6, in vitro transcription/translation product (15 μl) of HsPEX19 and HsPEX19C296S, respectively, using [3H]farnesyl pyrophosphate as label; 7 and 8, total (1 μl) and immunoprecipitate (3.5 μl) from in vitro transcription/translation product of HsPEX19C296S using [35S]methionine/cysteine. Solid and open arrowheads indicate farnesylated and nonfarnesylated Pex19p, respectively (see text).