unc-45 is a gene essential for muscle development and organization in C. elegans. Genetic evidence suggests that the
unc-45 gene product may be involved in muscle thick filament assembly. The cloning and sequencing of
unc-45 cDNA has shown that the amino terminus of the predicted
unc-45 protein contains three tetratricopeptide repeats (Venolia, et al., submitted). These motifs have been shown to be involved in protein-protein interactions. Our previous studies also show that the reporter genes (GFP and LacZ) driven by the
unc-45 promoter are expressed exclusively in muscle cells. Here we report that Northern analysis has determined that there is only one transcript (~3.0 kb) for
unc-45 gene as expected, the cDNA of
unc-45 gene fused to GFP and driven by
unc-45 promoter is expressed in muscle cells and can rescue the mutant phenotype at 25oC, Western blots show that there is one protein (~120 kD) detected. Moreover, microinjection of RNA from
unc-45 cDNA fragments into wildtype embryos cause them to arrest at the twofold to threefold stage. A yeast two-hybrid screen for proteins which interact with the UNC-45 protein is also under way.