Structure and expression of ubiquitin genes of Drosophila melanogaster.
We isolated and characterized two related ubiquitin genes from Drosophila melanogaster, polyubiquitin and UB3-D. The polyubiquitin gene contained 18 repeats of the 228-base-pair monomeric ubiquitin-encoding unit arranged in tandem. This gene was localized to a minor heat shock puff site, 63F, and it encoded a constitutively expressed 4.4-kilobase polyubiquitin-encoding mRNA, whose level was induced threefold by heat shock. To investigate the pattern of expression of the polyubiquitin gene in developing animals, a polyubiquitin-lacZ fusion gene was introduced into the Drosophila genome by germ line transformation. The fusion gene was expressed at high levels in a tissue-general manner at all life stages assayed. The ubiquitin-encoding gene, UB3-D, consisted of one ubiquitin-encoding unit directly fused, in frame, to a nonhomologous tail sequence. The amino acid sequence of the tail portion of the protein had 65% positional identity with that of yeast UBI3 protein, including a region that contained a potential nucleic acid-binding motif. The Drosophila UB3-D gene hybridized to a 0.9-kilobase mRNA that was constitutively expressed, and in contrast to the polyubiquitin gene, it was not inducible by heat shock.
Lee
H S
HS
Section of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, New York 14853.
Simon
J A
JA
Lis
J T
JT
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004331:Drosophila melanogaster / Q000235:genetics* / Q000378:metabolism; D005786:Gene Expression Regulation; D008969:Molecular Sequence Data; D012313:RNA / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D014018:Tissue Distribution; D014452:Ubiquitins / Q000235:genetics* / Q000378:metabolism
D014452:Ubiquitins; D012313:RNA; D004247:DNA