Figure S 1. A cdc53 strain is not UV
sensitive. UV sensitivity of wild-type (CDC53), cdc53-1, rad23∆, and cdc53-1rad23∆ strains. CDC53 encodes the essential yeast
cullin Cul1, a subunit in multiple E3 ubiquitin ligase complexes.
This graph shows the relative number of colonies that grew on agar
plates at 30° C following irradiation with the indicated doses of
UV light. For each strain, the number of colonies on the
unirradiated control was normalized to 100% survival. The
temperature-sensitive cdc53-1
strain displayed no sensitivity to UV light when grown at either
30° C or the semi-permissive temperature of 33° C (not
shown). In contrast to the effects seen with deletion of NEF4
subunit genes, a cdc53-1rad23∆
strain was significantly less UV sensitive than the rad23∆ strain. The basis for
this suppression is not known, but could be due to improved cell
survival resulting from cdc53-1-imposed
cell cycle delay. This analysis demonstrates that CDC53 does not have a unique role
in NER. As there is no enhanced UV sensitivity in the cdc53-1rad23∆ strain compared to
the single mutants, we conclude that CDC53
does not function in the NEF4 pathway.
Figure S 2. rtt101∆ and ygr003w∆ strains are not UV
sensitive. UV sensitivity of wild-type (WT), rtt101∆, ygr003w∆, rad23∆, ygr003w∆ rad23∆, and rtt101∆ rad23∆ strains was
determined as described in the legend to Figure S1. The error bars
represent the standard deviations determined from measurements made in
triplicate. RTT101 (also
known as CUL8) and YGR003W (also known as CUL3) encode the two nonessential
yeast cullins. rtt101∆
and ygr003w∆ strains had
wild-type sensitivity to UV light and did not affect the UV sensitivity
caused by rad23∆.
These cullins therefore do not appear to have a unique or essential
role in UV repair.