Suppression of the ecdysteroid‐triggered growth arrest by a novel Drosophila membrane steroid binding protein

Abstract

a b s t r a c tEcdysteroid is a crucial steroid hormone in insects, especially during metamorphosis. Here, we show that the Drosophila membrane steroid binding protein (Dm_MSBP) is a novel structural homolog of the vertebrate membrane-bound receptor component for progesterone. Dm_MSBP exhibited binding affinity to ecdysone when expressed on the cell surface of Drosophila S2 cells. In S2 cells, the stable overexpression of Dm_MSBP suppressed the growth arrest triggered by 20-hydroxyecdysone and prevented the temporal activation of extracellular signal-regulated kinase proteins. These results suggest that Dm_MSBP is a membranous suppressor to ecdysteroid and blocks the signaling by binding it in extracellular fluid.

Ecdysone Receptors: From the Ashburner Model to Structural Biology

“…In this context, the functional ecdysone receptor may be a homodimer of EcR or a heterodimer between EcR and another nuclear receptor, such as DHR3 (120). Furthermore, like other steroids, 20E has nongenomic effects that may be mediated by distinctly different membrane-bound receptors in D. melanogaster and Bombyx mori (39,40,45,102).…”

Evidence for a rapid cold hardening response in cultured Drosophila S2 cells

“…Thus, metabolic viability can be measured by the ability of mitochondria to metabolize resazurin. This method is used extensively to assay cell health in a variety of contexts (Riss et al, 2013) and has been used previously in Drosophila S2 cells (Fujii-Taira et al, 2009;Sharma and Fitzgerald, 2010). Further, in a pilot experiment we assessed viability with Trypan Blue, a dye exclusion assay, and the viability patterns detected were similar to those obtained with alamarBlue ( Fig.…”

A Novel Receptor Binding Progesterone, a Possible Transregulation Mechanism in the Rhipicephalus microplus-Host Interaction

“…On the other hand, PGRMC orthologues have been found in parasite organisms, including Schistosoma japonicum, Trichinella spiralis, Toxocara canis, and Taenia solium [30][31][32][33], and in invertebrate species like Drosophila melanogaster, where a homolog gene to PGRMC has been identified [34], and in Saccharomyces cerevisiae, where the PGRMC homolog, Dap1 was reported [35]. In addition, a progesterone receptor, closely related to PGRMC, in the marine rotifer Brachionus manjavacas suggests an ancient origin of steroid hormonal regulation [36].…”