Figure 5.

Mutant flies that have reduced phosphorylation of Arr2 have defects in the release of Arr2 from rhodopsin. Western blot of fractionated white-eyed control (w), S366A, norpA^P41 (norpA), and cam³⁵²/camⁿ³³⁹ (cam) mutant heads that were exposed to 10 s of blue light (B) or 10 s of blue light followed by 60 s of orange light (BO). Pellet (P) and supernatant (S) fractions were subjected to SDS/PAGE and Western analysis with antibodies directed against Arr2 and Rh1. cam³⁵² and camⁿ³³⁹ represent hypomorphic and null mutations, respectively, in the gene encoding calmodulin (37), whereas norpA^P41 (43) is a strong loss-of-function mutation in the eye-specific phospholipase C gene.