The clathrin-associated protein complex I(AP-1 complex) in C. elegans is composed of four adaptor proteins. Of the medium chains in the AP-1 complex of C. elegans, the first cloned is
unc-101 and the second chain cloned is
apm-1. Also, according to a search of the C. elegans genome, unlike the medium chains, only one each of the beta, gamma and sigma chains of the AP-1 complex exists in C. elegans. These facts support the possibility that the two medium chains in C. elegans compose distinct AP-1 complex while sharing the other chains, similar to mammalian
mu1a and
mu1b. From the RNAi and expression studies of AP-1 complex in C. elegans, we concluded that this hypothesis was correct. Since the expression of
unc-101 and
apm-1 is ubiquitous throughout development, and the functions of
unc-101 and
apm-1 are redundant in embryogenesis and vulval development while becoming distinct during larval development, we are interested in the distinct and similar functions of these chains as adaptor proteins. Mediums of the AP complexes are generally known to play a part in cargo selection of clathrin-coated vesicles, thus we have started experiments to elucidate their respective cargoes using the yeast two-hybrid system. We screened about 400,000 colonies with full-length
apm-1 cDNA as a bait, and found several positive clones. One of them, F29G6.3A, was the same clone that Marc Vidal group had found with
unc-101 as a bait(Albertha J.M Walhout et al., Science ?????). We have also found several novel proteins, and will present analyses on the candidate genes