Cyclic nucleotide-gated (CNG) channels localize exclusively to the plasma membrane of photosensitive outer segments of rod photoreceptors where they generate the electrical response to light. Here, we report the finding that targeting of CNG channels to the rod outer segment required their interaction with ankyrin-G. Ankyrin-G localized exclusively to rod outer segments, coimmunoprecipitated with the CNG channel, and bound to the C-terminal domain of the channel beta1 subunit. Ankyrin-G depletion in neonatal mouse retinas markedly reduced CNG channel expression. Transgenic expression of CNG channel beta-subunit mutants in Xenopus rods showed that ankyrin-G binding was necessary and sufficient for targeting of the beta1 subunit to outer segments. Thus, ankyrin-G is required for transport of CNG channels to the plasma membrane of rod outer segments.
PubMed ID: 19299621
PMC ID: PMC2792576
Article link: Science.
Grant support: EY12859 NEI NIH HHS , Howard Hughes Medical Institute , R01 EY012859-10 NEI NIH HHS , P30 EY005722-23 NEI NIH HHS , P30 EY005722 NEI NIH HHS , R01 EY012859 NEI NIH HHS
Genes referenced: ank1 ank3