Skip to Main content Skip to Navigation
Journal articles

Kir4.1 and AQP4 associate with Dp71- and utrophin-DAPs complexes in specific and defined microdomains of Müller retinal glial cell membrane.

Abstract : The dystrophin-associated proteins (DAPs) complex consisting of dystroglycan, syntrophin, dystrobrevin, and sarcoglycans in muscle cells is associated either with dystrophin or its homolog utrophin. In rat retina, a similar complex was found associated with dystrophin-Dp71 that serves as an anchor for the inwardly rectifying potassium channel Kir4.1 and the aqueous pore, aquaporin-4 (AQP4). Here, using immunofluorescence imaging of isolated retinal M?r glial cells and co-immunoprecipitation experiments performed on an enriched M?r glial cells end-feet fraction, we investigated the effect of Dp71 deletion on the composition, anchoring, and membrane localization of the DAPs-Kir4.1 and/or -AQP4 complex. Two distinct complexes were identified in the end-feet fraction associated either with Dp71 or with utrophin. Upon Dp71 deletion, the corresponding DAPs complex was disrupted and a compensating utrophin upregulation was observed, accompanied by diffuse overall staining of Kir4.1 along the M?r glial cells and redistribution of the K(+) conductance. Dp71 deficiency was also associated with a marked reduction of AQP4 and beta-dystroglycan expression. Furthermore, it was observed that the Dp71-DAPs dependent complex could be, at least partially, associated with a specific membrane fraction. These results demonstrate that Dp71 has a central role in the molecular scaffold responsible for anchoring AQP4 and Kir4.1 in M?r cell end-feet membranes. They also show that despite its close relationship to the dystrophin proteins and its correlated upregulation, utrophin is only partially compensating for the absence of Dp71 in M?r glial cells. (c) 2008 Wiley-Liss, Inc.
Document type :
Journal articles
Complete list of metadatas

Cited literature [31 references]  Display  Hide  Download

https://www.hal.inserm.fr/inserm-00265573
Contributor : Dominique Jean-Marie Mornet <>
Submitted on : Wednesday, March 19, 2008 - 3:53:19 PM
Last modification on : Thursday, July 16, 2020 - 1:48:05 PM
Long-term archiving on: : Friday, November 25, 2016 - 10:04:29 PM

File

 Restricted access
To satisfy the distribution rights of the publisher, the document is embargoed until : jamais

Please log in to resquest access to the document

Identifiers

Citation

Patrice Fort, Abdoulaye Sene, Thomas Pannicke, Michel Roux, Valérie Forster, et al.. Kir4.1 and AQP4 associate with Dp71- and utrophin-DAPs complexes in specific and defined microdomains of Müller retinal glial cell membrane.. Glia, Wiley, 2008, 56 (6), pp.597-610. ⟨10.1002/glia.20633⟩. ⟨inserm-00265573⟩

Share

Metrics

Record views

356