FIG. 1.

4.1R interacts with CPAP in a yeast two-hybrid system. The CPAP (Q1) clone was first isolated by a yeast two-hybrid screen from a human lymphocyte cDNA library using the head domain (residues 1 to 209) of 4.1R-135 as bait (4.1R-HD). (A) Mapping the region of 4.1R-135 that interacts with CPAP. The constructs containing various portions of 4.1R-135 fused in-frame to the Gal4 DNA-binding domain were cotransformed with a Q1-ACT2 clone that expressed CPAP (residues 897 to 1338) fused to the activation domain of Gal4. The expression (+) or nonexpression (−) of the lacZ reporter gene using a colony-lift assay is shown. The column on the right represents the liquid assay for β-galactosidase (β-gal) activity using ONPG as a substrate. (B) Schematic drawing of the overlapping CPAP cDNA clones that span the entire coding region of CPAP.