Antibody identification, chromosome map assignment, and sequence analysis of a Rab escort protein homolog in Drosophila

Using a polyclonal antiserum a cDNA encoding a Rab escort protein (REP) hom olog in DI Drosophila has been identified and sequenced. The gene encodes a 511 residue protein with a predicted molecular mass of 56 855 Da. Antibody labeling demonstrates that Drosophila REP protein is present in the early embryo and that it is being apportioned uniformly throughout the embryo in a process likely to be linked to the syncytial nuclear divisions. In situ h ybridization to polytene chromosomes reveals that the Drosophila REP gene i s located in the 56E region on the second chromosome. Drosophila REP is the first invertebrate REP homolog to be identified and characterized. (C) 199 9 Elsevier Science. B.V. All rights reserved.