A protein product of the Drosophila recessive tumor gene, l (2) giant gl, potentially has cell adhesion properties.

In the fruitfly Drosophila melanogaster the recessive mutation lethal (2) giant larvae affects cell growth and cell adhesion properties of neural and imaginal disc cells during embryonic and larval development. Here we report the nucleotide sequence of a cDNA from one of the two major transcripts of the l (2) gl gene containing a 3.5-kb open reading frame. From the deduced amino acid sequence we predict a 130-kd protein with certain sequence similarities to proteins with cell adhesion properties. We have raised antibodies against bacterial fusion proteins encoded by cDNA subfragments. Affinity-purified specific antibodies recognize a 130-kd protein in wild-type protein extracts and in situ, which is missing in the mutant. Localization of the l (2) gl protein in tissue sections indicates that the l (2) gl protein is associated with cellular membranes and probably involved in cell-cell interaction.