TABLE 1.
Induction of wild-type [URE3] by heterologous prion domains
| Overexpressed prion domaina | USA+ colonies/ 106 cellsb | USA+ stabilityc | USA+ dominanced | Cytoductione | |
|---|---|---|---|---|---|
| Isolate A | Isolate B | ||||
| Vector | 1.3 ± 0.3 | 7/20 | 4/7 | 20/20 | 19/20 |
| Wild typef | 23 ± 3 | 12/20 | 8/12 | 18/20 | 20/20 |
| URE2-21 | 17 ± 3 | 12/20 | 7/12 | 20/20 | 20/20 |
| URE2-22 | 10 ± 5 | 18/20 | 17/18 | 20/20 | 20/20 |
| URE2-23 | 130 ± 12 | 14/20 | 7/14 | 17/20 | 20/20 |
| URE2-24 | 18 ± 1 | 15/20 | 7/15 | 14/20 | 18/20 |
| URE2-25 | 27 ± 6 | 19/20 | 18/19 | 20/20 | 18/20 |
| SUP35 | <1.0 | 5/20 | 1/5 | ND | ND |
| SUP35-21 | <1.0 | 6/20 | 4/6 | ND | ND |
| SUP35-24 | <1.0 | 5/20 | 2/5 | ND | ND |
| SUP35-25 | <1.0 | 7/20 | 3/7 | ND | ND |
| SUP35-26 | <1.0 | 4/20 | 0/4 | ND | ND |
|
SUP35-27 |
<1.0 |
6/20 |
5/6 |
ND |
ND |
Yeast strain YER135 was transformed with either a plasmid containing the GAL1 promoter (pH 317, vector) or pH 317 modified to express the indicated prion domain from the GAL1 promoter.
Yeast were grown in galactose/raffinose medium for 3 days and plated onto USA medium to select for prion-containing cells. Data are the number of USA+ colonies per 106 cells and represent the mean of three independent experiments. Standard errors are indicated.
The fraction of USA+ colonies that remained USA+ after 48 hr of growth on YPAD. ND, not determined.
The fraction of stable USA+ colonies whose USA+ phenotype was dominant when mated with [ure-o] cells carrying a chromosomal copy of wild-type URE2.
Two stable dominant USA+ isolates were used as cytoduction donors. The [ure-o] recipient strain carried a wild-type chromosomal copy of URE2. The numbers indicated the fraction of cytoductants that were USA+.
Efficient induction by the wild-type prion domains has previously been reported (Masison and Wickner 1995), but is included here as a positive control.