Genetic engineering with a gene encoding a soybean storage protein to identify DNA sequences to control its expression: Annual report, 1993

摘要

The (beta)-conglycinins are soybean storage proteins encoded by genes that are tightly regulated both spatially and temporally. The author has studied the Soybean Embryo Factors that bind to the cis elements that are presumably involved in regulating the expression of these gene promoters using both in vitro binding assays and in vivo expression assays in transgenic plants. The results obtained to date have made it evident that there are no clear correlations between the in vivo and the in vitro results, i.e., changes in single nucleotides that alter protein:DNA interactions can have little or no impact on expression of the promoters in vivo. In contrast, the CATGCAT (RY element) sequence, for which no binding proteins have been identified, appear to be very important for controlling gene expression. Although the author has been attempting to isolate and characterize the SEF 3 and SEF 4 proteins he has to date not been successful using protein expression libraries derived from embryo cDNAs. He is continuing experiments of this type, as well as more standard protein purification procedures. He has constructed a number of chimeric promoters with different upstream and downstream regulatory sequences in an attempt to identify, by expression assays in transgenic plants, those sequences that are uniquely responsible for the temporal and spatially regulated expression of the (beta)-conglycinin genes. Because of the results of previously published work from this laboratory, the author concluded that the core promoters themselves may be responsible for the regulation. Therefore, he has focused his efforts on these sequences, the RY element, and the SEF 3 binding sequences. In a follow-up to the studies to modify the expression of genes in seeds, he will express several types of human and other animal genes in seeds of transgenic plants. (ERA citation 19:013140)