Rr. Mckay et al., A DROSOPHILA GENE THAT ENCODES A MEMBER OF THE PROTEIN DISULFIDE ISOMERASE PHOSPHOLIPASE C-ALPHA FAMILY/, Insect biochemistry and molecular biology, 25(5), 1995, pp. 647-654
Screening of a Drosophila genomic DNA library at reduced stringency hy
bridization conditions using a rat PLC alpha cDNA probe yielded a gene
which encodes a member of the protein disulfide isomerase/PLC alpha f
amily. The gene has been localized to band 74C on the left arm of the
third chromosome and has been designated dpdi. Northern analysis shows
that the dpdi gene encodes a transcript that is 2.3 kb in length and
is present throughout development as well as in both heads and bodies
of adults. The deduced dpdi protein is 496 amino acids in length and c
ontains two domains exhibiting high similarity to thioredoxin, two reg
ions that are similar to the hormone binding domain of human estrogen
receptor, and a sequence of four amino acids (KDEL) at the C-terminus
which has been described by others as being responsible for retention
of proteins in the endoplasmic reticulum. Overall, dpdi contains a hig
her similarity to rat protein disulfide isomerase (53% identical) than
to rat PLC alpha (30% identical). However, it is unclear whether dpdi
functions in vivo as a PDI or as a PLC, or both. Drosophila, with its
well characterized genetics and the ability to generate mutants in a
gene that has been cloned, provides an excellent system in which to re
solve this issue.