(A) A schematic
comparison of amino acid sequences of RBP-J and RBP-L. Closed boxes
represent DNA binding regions of RBP-J with the designations N (amino
acids 212–227) and C (amino acids 275–323) (16,31).
A vertically hatched box represents the RAM binding domain (amino
acids 196–372) of RBP-J (16). The regions Jn, Jm and Jc
are explained in the text: Ln, Lm and Lc are the corresponding regions
in RBP-L. The percentage of each region represents the relative
amino acid sequence homology between RBP-J and RBP-L. (B)
Transcriptional activities of chimeras of RBP-J and RBP-L. Components
from RBP-J and RBP-L are displayed as black and white bars, respectively.
The numbers of amino acids correspond to their positions on RBP-J.
RAMIC-dependent transcriptional activities of chimeras and GAL4-chimera
fusions were evaluated by the same approach as shown in Figure 1
and are represented as relative to RBP-J and GAL4–RBP-J,
respectively. (C) The transcriptional activities
of chimeras by increasing amounts of activators are demonstrated.
Aliquots of 10 ng of pCMX RBP-J, RBP-L or chimeras were constantly
introduced into a well of OT11 cells with 0.5 µg
of pGa981-6, 0.25 µg of pCMXlacZ and
0.25 or 1.0 µg of activators in pEFBOSneo. The
scales of relative luciferase units in RBP-J, RBP-L, JLJ and LJL
are equal to each other.