Interaction between beaded filament proteins CP 49 and CP 115 revealed by the yeast 2 hybrid system

Purpose. Evidence linking CP 49 md CP 115 to the Beaded Filament (BF) as well as evidence for the relatedness of these two proteins to the Intermediate Filament (IF) family has been previously presented. We began experiments to determine if the yeast two hybrid system could be used to study the assembly/interaction between CP 49 and CP 115. Methods. cDNA sequences for bovine CP 115, mouse CP 49 and human vimentin were manipulated using standard molecular biology techniques and cloned into the appropriate screening plasmids. DNA constructs containing various combinations of these cDNA sequences were introduced into yeast and activity of the beta-Galactosidase reporter monitored. Results. Using human vimentin as a positive control, we have shown that the two hybrid system is useful for the study of Intermediate Filament assembly. In addition, our data show that a specific interaction occurs between CP 115 and CP 49, providing additional experimental tools to study CP 115 and CP 49 assembly. Conclusions The yeast two hybrid system provides functional evidence for an initial IF like assembly process (heteromer formation) between the lens specific Beaded Filament proteins CP 49 and CP115.