Figure 2. Prox1 interacted with the IDCL
and the carboxyl-terminal domain of PCNA. A: Diagram of the
structure of full length PCNA and the structure of the truncations used
in this study. N+ (amino acids 1-135 of PCNA); C+ (amino acids 115-261
of PCNA); C- (amino acids 135-261 of PCNA); C-term, the original clone
from the yeast two hybrid screen (amino acids 167-261 of PCNA). B:
Yeast strain AH109 transformed with a vector expressing a fusion
between the DNA binding domain of GAL4 and the HDPD of Prox1 was mated
with yeast strain Y187 transformed with a vectors expressing either the
activation domain of GAL4 fused to the C-term fragment of PCNA (2), the
C- fragment of PCNA lacking the IDCL (3), the C+ fragment of PCNA which
includes the IDCL (4), the N+ fragment of PCNA (5) or full length PCNA
(6). The interaction between P53 and SV40 large T-antigen was used as a
positive control (1). Colonies from the original DO plates were
re-streaked on either DO plates (to demonstrate presence of all vectors
in the yeast) or quadruple drop out (QDO) plates to test for
interaction between the protein products. C: QDO liquid
cultures were grown of the yeast able to grow under QDO conditions and
the relative amount of expression from the β-galactosidase reporter
gene was determined by ONPG assays.