title: Phosphodiesterase 6β Expression In Developing Mouse Retina.
abstract: Therd1mouse is a well-studied model of retinitis pigmentosa (RP), an inherited retinal degenerative disease affecting approximately 1 in 4000 people. It is characterized by a mutation in thePde6bgene that codes for Phosphodiesterase 6β (PDE6β), a downstream effector of phototransduction.Pde6bgene expression occurs embryonically in mouse retina, whereas other proteins involved in phototransduction are expressed around postnatal day 5 (P5). The primary aim of this study is to investigate the temporal and spatial expression pattern of PDE6β protein during photoreceptor development. Using Western blots with wild type andrd1mouse retinas from P2 - P21 we demonstrated that PDE6β protein is expressed in wild type retinas by P2 and is not detected inrd1retinas. The earliest detection of PDE6β in wild type retinas by immunohistochemistry was at P6, where it was confined to the apical region of the photoreceptor layer. The expression of PDE6β protein prior to differentiation of photoreceptor cells and prior to expression of other phototransduction proteins is consistent with the hypothesis that PDE6β may play a role during photoreceptor development distinct from its role in phototransduction. Our lab previously showed that Prenylated Rab Acceptor 1 (PRA1), a vesicular trafficking protein, is downregulated in the developingrd1retina, although its function in the retina is unknown. The second aim of this study was to explore the relationship between PRA1 and PDE6β. We used immunohistochemistry to determine whether the two proteins are co-localized during the postnatal differentiation period. However, no co-localization between PDE6β and PRA1 was detected. The function of PRA1 in developing retina remains to be elucidated.
authors.affiliation: Department of Biology, Saint Louis University, St. Louis, Missouri 63103.
authors.forename: Fadi
authors.initials: F
authors.lastname: Assaf
authors.affiliation: Department of Biology, Saint Louis University, St. Louis, Missouri 63103.
authors.forename: Ju
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Biology, Saint Louis University, St. Louis, Missouri 63103.
authors.forename: Judith Mosinger
authors.initials: JM
authors.lastname: Ogilvie
keywords: PDE6β; PRA1; cGMP; development; mouse; photoreceptor; retinal degeneration; trafficking