Purpose: Biochemical studies have shown that phosducin, a photoreceptor phosphoprotein, competes with Tα in binding to TβΓ. It was suggested that phosducin could modulate the transduction cascade by controlling the recycling of TβΓ. Initial studies demonstrated phosducin was not involved in the primary transduction cascade. The purpose of this study was to follow the responsivity of the photoreceptors during dark- and light-adaptation in a transgenic mouse line cairying a mutant phosducin gene which prevents it from being phosphorylated. Methods: Transgenic mice were constructed in which serine 73 of the phosducin gene was replaced by isoleucine. ERGs were used to follow the adaptational process. Results: Following standard bleaching, the recovery of b-wave amplitude at one hour was ∼90% of the pre-exposure level in normals (n=10) and ∼50% in the transgenics (n=10) . The expected increase in the b-wave amplitude during light-adaptation was sigr ificantly lower in the transgenics than in the controls (57% vs 165%). Conclusions: These data suggest that phosoducin can play a role in the adaptational process of the photoreceptors.
|Journal||Investigative Ophthalmology and Visual Science|
|Publication status||Published - 1996 Feb 15|
ASJC Scopus subject areas
- Sensory Systems
- Cellular and Molecular Neuroscience