This project involves the study of two metal binding proteins (MBP1 and MBP2) in the brine shrimp Artemia salina. Since MBP1 resembles mammalian metallothionein and MBP2 can be induced by cadmium, we are using Artemia as a model system for the study of eukaryotic gene expression and trace metal metabolism. It has been suggested that cellular malignancy is a result of abnormal gene expression. The presence of oncogenes in normal and transformed cells further enhances the intimate role of gene expression in determination of cell pathology. Mammaliam metallothionein is capable of binding heavy metals and has been implicated in both metal detoxification and as having a central role in normal metal metabolism. Trace metal homeostasis and its involvement in human health is becoming increasingly evident. Whatsmore, evidence is mounting regarding the direct involvement of trace metals in regulation of gene transcription and other biological processes. Studies will be initiated to determine whether Artemia respond to copper and zinc in a fashion similar to that observed with cadmium. Both metal binding proteins will be purified by standard chromatographic procedures and their primary sequence determined. Insights into metal flux in vivo will involve pulse chase experiments using radioactive cadmium. Future studies would involve determining biosynthetic and turnover rates of these proteins in conjunction with metal flux. Using cDNA from mouse MT1, changes in transcriptional capabilities will be evalauted by Northern hybridization techniques. Subsequently, information gleaned from these studies would be used to determine if these proteins are developmentally regulated and any possible correlation exists between metal sensitivity of the organism and age. Finally, total genomic DNA will be screen for the presence of MT-like gene sequences and a partial restriction map of this region delineated for future cloning experiments.
