Cloning and functional analysis of tipE, a novel membrane protein that enhances drosophila para sodium channel function

Abstract

Voltage-dependent sodium channels are involved in the initiation and propagation of action potentials in many excitable cells. Here we report that tipE, a gene defined by a temperature-sensitive paralytic mutation in Drosophila, encodes a novel integral membrane protein that dramatically stimulates functional expression in Xenopus oocytes of the Drosophila sodium channel α subunit encoded by the paralytic (para) locus. Using a heat shock promoter to control tipE⁺ gene expression in transgenic flies, we demonstrate that tipE⁺ gene expression is required during pupal development to rescue adult paralysis. In addition, we demonstrate a role or the tipE gene product in adults.