Sorting Light Receptors

摘要

In the retina, cyclic nucleotide gated (CNG) channels initiate the electrical response to light in the sensory cilia of the rods. The channels are exclusively localized to outer segments of the cilia, but how they are positioned has been largely unknown. Working on Xenopus, Kizhatil et al. (p. 1614) showed that the CNG-β subunit bound to ankyrin-G, a membrane scaffolding protein, is not only required for the post-Golgi transport of CNG channels, but is also required for rod outer segment development. A human mutation in the CNG-β subunit disrupts this targeting mechanism and is associated with retinitis pigmentosa. Similar ankyrin-G-based mechanisms may occur in olfactory cilia, in the sperm flagella, and other sites.