Alternative splicing of a Drosophila tropomyosin gene generates muscle tropomyosin isoforms with different carboxy-terminal ends.
AUTOR(ES)
Basi, G S
RESUMO
The muscle tropomyosin I (mTm I) gene from Drosophila melanogaster has been analyzed and shown to express a complex transcription unit consisting of two sets of tissue-specific mRNAs. A 1.3- and 1.6-kilobase set of mRNAs is expressed during myogenesis in embryos, and in myogenic cell cultures. The mRNAs encode a 34,000-dalton muscle tropomyosin isoform. The same mTm I gene expresses a different set of 1.7- and 1.9-kilobase mRNAs in thoracic flight muscle tissue of the adult. The thorax RNAs encode a new tropomyosin isoform resolved on two-dimensional gels. The structure of the gene has been determined, and we show that the embryonic and thoracic mRNAs are generated by alternative splicing. The alternate exon splicing patterns determine a different 27 amino acids at the carboxy-terminal end of the two tropomyosin isoforms. These results show that the carboxy-terminal domain of tropomyosin is highly regulated in determining tropomyosin function. The results also show that contractile protein isoforms can be generated by single as well as multiple genes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=369294Documentos Relacionados
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