title: Light-regulated interaction of Dmoesin with TRP and TRPL channels is required for maintenance of photoreceptors.
abstract: Recent studies in Drosophila melanogaster retina indicate that absorption of light causes the translocation of signaling molecules and actin from the photoreceptor's signaling membrane to the cytosol, but the underlying mechanisms are not fully understood. As ezrin-radixin-moesin (ERM) proteins are known to regulate actin-membrane interactions in a signal-dependent manner, we analyzed the role of Dmoesin, the unique D. melanogaster ERM, in response to light. We report that the illumination of dark-raised flies triggers the dissociation of Dmoesin from the light-sensitive transient receptor potential (TRP) and TRP-like channels, followed by the migration of Dmoesin from the membrane to the cytoplasm. Furthermore, we show that light-activated migration of Dmoesin results from the dephosphorylation of a conserved threonine in Dmoesin. The expression of a Dmoesin mutant form that impairs this phosphorylation inhibits Dmoesin movement and leads to light-induced retinal degeneration. Thus, our data strongly suggest that the light- and phosphorylation-dependent dynamic association of Dmoesin to membrane channels is involved in maintenance of the photoreceptor cells.
authors.affiliation: Department of Physiology, The Hebrew University-Hadassah Medical School, Jerusalem 91120, Israel.
authors.forename: Irit
authors.initials: I
authors.lastname: Chorna-Ornan
authors.forename: Vered
authors.initials: V
authors.lastname: Tzarfaty
authors.forename: Galit
authors.initials: G
authors.lastname: Ankri-Eliahoo
authors.forename: Tamar
authors.initials: T
authors.lastname: Joel-Almagor
authors.forename: Nina E
authors.initials: NE
authors.lastname: Meyer
authors.forename: Armin
authors.initials: A
authors.lastname: Huber
authors.forename: François
authors.initials: F
authors.lastname: Payre
authors.forename: Baruch
authors.initials: B
authors.lastname: Minke
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000737:chemistry; D003600:Cytosol / Q000737:chemistry; D029721:Drosophila Proteins / Q000378:metabolism*; D008027:Light; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D009154:Mutation; D010766:Phosphorylation; D017956:Photoreceptor Cells, Invertebrate / Q000378:metabolism / Q000502:physiology* / Q000528:radiation effects; D021381:Protein Transport / Q000528:radiation effects; D050051:Transient Receptor Potential Channels / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D008565:Membrane Proteins; D050051:Transient Receptor Potential Channels; C099886:moesin, Drosophila; C074192:trpl protein, Drosophila