Fig. 3.

Ceramidase expression facilitates the endocytic turnover of Rh1. (A) A pulse of 1D4-tagged Rh1 was induced in w1118 control flies by heat shock for 1 h at 37°C, and proteins were extracted from these fly retinas on days 1, 2, 4, 7, and 8 and were analyzed by Western blot for the tagged Rh1. The Rh1 level peaked between 1 and 2 days and decreased in amount thereafter, and a signal was still detected on day 8. (B) A pulse of 1D4-tagged Rh1 was induced as in A in flies expressing UAS-ceramidase under a GMR-GAL4 driver. In these flies the Rh1 peaked as in control retina, however, the tagged Rh1 was not visible beyond day 4. The blots were probed for IPP as loading controls (Lower).