期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1990
卷号：87
期号：6
页码：2112-2116
DOI：10.1073/pnas.87.6.2112
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The trithorax (trx) gene functions in segment determination in Drosophila through interaction with genes of the bithorax complex and Antennapedia complex. Genetic evidence suggests that trx may be considered a positive regulator of homeotic genes. Sequencing of cDNAs corresponding to the entire trx transcription unit revealed the existence of an unusually long open reading frame encoding 3759 amino acids. The main features of the predicted trx protein are several cysteine-rich regions which can be folded into zinc finger-like domains. Cysteine-rich portions expressed from trx cDNAs in Escherichia coli are capable of zinc binding in vitro, suggesting a possible function for the trx product as a metal-dependent DNA-binding protein. Analysis of trx mutant embryos with antibody to the Ultrabithorax (Ubx) gene product showed decreased staining in parasegment 6 of the ventral nerve cord of late embryos. However, expression of Ubx was not affected in embryos carrying the lethal mutation trxE3, in which one of the putative zinc finger-like domains of the trx protein is deleted. This differential effect of the E3 mutation suggests that trx exhibits other function(s) besides those involved in the regulation of Ubx expression in the ventral nerve cord of the embryo.
