Tissue-specific and constitutive alpha-tubulin genes of Drosophila melanogaster code for structurally distinct proteins.
AUTOR(ES)
Theurkauf, W E
RESUMO
We have determined the nucleotide sequences of all four Drosophila alpha-tubulin genes (alpha 1, alpha 2, alpha 3, and alpha 4). Two of the genes, alpha 1 and alpha 3, are constitutively expressed and code for proteins that are very similar to previously sequenced alpha-tubulins. They differ from each other by only two amino acid substitutions. These two genes also have blocks of homology between the noncoding leader regions of their transcription units. In contrast to these constitutive genes, the tissue-specific alpha 2 and alpha 4 genes code for tubulins with different structures. The alpha 2 mRNA is male-specific in adults and codes for a tubulin that differs from alpha 1 at 21 of the 450 residues. Six nonconservative substitutions are clustered within the 14 carboxyl-terminal amino acids, a region implicated in the regulation of microtubule assembly. The alpha 4 mRNA is maternal and is found only in ovarian nurse cells, eggs, and early embryos. It codes for the most highly divergent alpha-tubulin yet reported and differs from alpha 1 at 149 positions.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=386953Documentos Relacionados
- The two alpha-tubulin genes of Chlamydomonas reinhardi code for slightly different proteins.
- Genetically essential and nonessential alpha-tubulin genes specify functionally interchangeable proteins.
- Two functional alpha-tubulin genes of the yeast Saccharomyces cerevisiae encode divergent proteins.
- Structure of two human alpha-tubulin genes.
- Complete sequence of three alpha-tubulin cDNAs in Chinese hamster ovary cells: each encodes a distinct alpha-tubulin isoprotein.
