The Drosophila melanogaster actin 5C gene uses two transcription initiation sites and three polyadenylation sites to express multiple mRNA species.

AUTOR(ES)

Bond, B J

RESUMO

At least six mRNAs are made from the Drosophila melanogaster act5C gene. We investigated the structures of these RNAs in detail and determined that they are heterogeneous at both their 5' and 3' ends. At the 5' end there were two nonhomologous leader exons which were alternately spliced to the remainder of the gene. These leader exons mapped to 1.7 and 0.7 kilobases, respectively, upstream of a common splice acceptor site which was eight base pairs 5' to the translation initiator AUG. Exon 1 is 147 bases in length, while exon 2 is 111 bases. A consensus TATA sequence was found roughly 30 base pairs upstream from exon 1, but none was found in the analogous position upstream of exon 2. The transcript length diversity arose principally from the use of three polyadenylation sites. This gave rise to RNA molecules with 3'-untranslated regions of roughly 375, 655, and 945 base pairs. With two start sites and three termination sites, this gene has the potential to produce six different transcripts. All six possible transcripts were present in whole fly mRNA. Transcripts containing the two different leader exons were found in roughly the same relative quantities through development. In contrast, the various 3' ends were differentially represented through development.

Documentos Relacionados

• Regulatory elements mediating transcription from the Drosophila melanogaster actin 5C proximal promoter.
• Positive and negative regulatory elements mediating transcription from the Drosophila melanogaster actin 5C distal promoter.
• Multiple mRNA species generated by alternate polyadenylation from the rat manganese superoxide dismutase gene.
• Analyses of the mRNA transcription processes of snowshoe hare bunyavirus S and M RNA species.
• Human Cu/Zn superoxide dismutase gene: molecular characterization of its two mRNA species.