The complete sequence of Drosophila alpha-spectrin: conservation of structural domains between alpha-spectrins and alpha-actinin.
We report the complete sequence of Drosophila alpha-spectrin and show that it is similar to vertebrate nonerythroid spectrins. As in vertebrates, the alpha subunit consists of two large domains of repetitive sequence (segments 1-9 and 11-19) separated by a short nonrepetitive sequence (segment 10). The 106-residue repetitive segments are defined by a consensus sequence of 54 residues. Chicken alpha-spectrin (Wasenius, V.-M., M. Saraste, P. Salven, M. Eramaa, L. Holm, V.-P. Lehto. 1989. J. Cell Biol. 108:79-93) shares 50 of these consensus positions. Through comparison of spectrin and alpha-actinin sequences, we describe a second lineage of spectrin segments (20 and 21) that differs from the 106-residue segments by an 8-residue insertion and by lack of many of the consensus residues. We present a model of spectrin evolution in which the repetitive lineage of spectrin segments and the nonrepetitive lineage of segments found in spectrin and alpha-actinin arose by separate multiplication events.
Dubreuil
R R
RR
Department of Cellular and Developmental Biology, Harvard University, Cambridge, Massachusetts 02138.
Byers
T J
TJ
Sillman
A L
AL
Bar-Zvi
D
D
Goldstein
L S
LS
Branton
D
D
D000185:Actinin / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D002645:Chickens; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D004023:Dictyostelium / Q000235:genetics; D004330:Drosophila / Q000235:genetics*; D008969:Molecular Sequence Data; D012091:Repetitive Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid; D013049:Spectrin / Q000235:genetics*
D000185:Actinin; D013049:Spectrin; D004247:DNA