First Author | Kizhatil K | Year | 2009 |
Journal | Exp Eye Res | Volume | 88 |
Issue | 1 | Pages | 57-64 |
PubMed ID | 19007774 | Mgi Jnum | J:145566 |
Mgi Id | MGI:3835238 | Doi | 10.1016/j.exer.2008.09.022 |
Citation | Kizhatil K, et al. (2009) Ankyrin-B is required for coordinated expression of beta-2-spectrin, the Na/K-ATPase and the Na/Ca exchanger in the inner segment of rod photoreceptors. Exp Eye Res 88(1):57-64 |
abstractText | Rod photoreceptors are highly polarized cells whose exquisite sensitivity to light depends on precise compartmentalization of ion channels/transporters within specialized membrane domains. Here, we report evidence for an ankyrin-B based mechanism for coordinated expression of the beta-2-spectrin-based membrane skeleton, and the Na/K-ATPase and Na/Ca exchanger in the inner segment of rod photoreceptors. We first discovered that ankyrin-B localizes to the inner segments but not outer segments of rod photoreceptors in vertebrates including humans, mice, and frogs. We found that haploinsufficiency of ankyrin-B in mice is accompanied by 50% reduction in inner segments of membrane proteins, including the Na/K-ATPase and the Na/Ca exchanger, as well as beta-2-spectrin, which is a component of the spectrin-actin membrane skeleton. These results are consistent with a mechanism where ankyrin-B is required to restrict the Na/K-ATPase and Na/Ca exchanger to the inner segment of rod photoreceptors by tethering these membrane proteins to beta-2-spectrin. |