FIG. 4.

Different phenotypes of cet1 in the presence of overexpressed yeast and mouse guanylyltransferases. The CET1/CEG1 double shuffling strain YSB719 was transformed with: pRS425-CEG1 (2μm, LEU2) (A) or pAD5-MCE(211–597) (2μm, LEU2, which expresses mouse guanylyltransferase domain tagged with the epitope of influenza virus hemagglutinin (HA) under the control of ADH1 promoter) (B) Leu⁺ isolates were subsequently transformed with pRS313 (vector; carries HIS3 and CEN/ARS) or derivatives thereof carrying wild-type or mutant CET1 alleles. Leu⁺ His⁺ transformants were grown in the presence of 5-FOA to shuffle out the wild-type genes carried on pRS316-CEG1-CET1. After 2 days, FOA-resistant cells were spotted on new plates and further incubated for 2 days at 30 or 37°C as indicated. (C) Summary of the results shown in panels A and B.