Rr. Dubreuil et Jq. Yu, ANKYRIN AND BETA-SPECTRIN ACCUMULATE INDEPENDENTLY OF ALPHA-SPECTRIN IN DROSOPHILA, Proceedings of the National Academy of Sciences of the United Statesof America, 91(22), 1994, pp. 10285-10289
We report the identification and initial characterization of Drosophil
a melanogaster ankyrin. Oligonucleotide printers based on the spectrin
-binding domain of human brain ankyrin were used to amplify Drosophila
genomic DNA. A cloned 184-bp PCR product was used to isolate Drosophi
la ankyrin cDNAs. Ankyrin cDNA probes detected a 5.5-kb transcript fro
m embryonic poly(A)(+) RNA and a single polytene chromosome locus (101
F-102A). The cDNA sequence encodes a 170-kDa protein that is 53% ident
ical to human brain ankyrin (Ank2). Antibodies directed against a reco
mbinant fragment of Drosophila ankyrin reacted with a 170-kDa polypept
ide from Drosophila embryos, larvae, S2 cells, and adult flies. The an
kyrin antibody coimmunoprecipitated alpha- and beta-spectrin with anky
rin in detergent extracts of Drosophila embryo membranes. Antibodies a
gainst Drosophila ankyrin, alpha-spectrin and beta-spectrin were used
to detect these proteins in wild-type and alpha-spectrin-mutant larvae
. alpha-Spectrin levels were greatly diminished in mutant larvae, but
levels of ankyrin and beta-spectrin were indistinguishable from wild t
ype. The persistence of ankyrin and beta-spectrin may explain the rela
tively mild phenotype of alpha-spectrin mutants during early Drosophil
a development.