Localization of dystrophin isoform Dp71 to the inner limiting membrane of the retina suggests a unique functional contribution of Dp71 in the retina |
| |
Authors: | Howard PL; Dally GY; Wong MH; Ho A; Weleber RG; Pillers DA; Ray PN |
| |
Institution: | Department of Medical and Molecular Genetics, University of Toronto, Toronto, Ontario, Canada. |
| |
Abstract: | The electroretinograms (ERGs) of patients with Duchenne muscular dystrophy
and an allelic variant of the mdx mouse (mdxCv3) have been shown to be
abnormal. Analysis of five allelic variants of the mdx mouse with mutations
in the dystrophin gene has shown that there is a correlation between the
position of the mutation and the severity of the ERG abnormality. Three
isoforms are expressed in the retina: Dp427, Dp260 and Dp71. Using indirect
immunofluorescence and isoform-specific antibodies on retinal sections from
three allelic mdx mouse strains, we have examined the localization of each
of the isoforms. We show that Dp71 expression does not overlap with Dp427
and Dp260 expression at the outer plexiform layer (OPL). Instead, Dp71 is
localized to the inner limiting membrane (ILM) and to retinal blood
vessels. Moreover, we show that Dp260 and Dp71 differ structurally at their
respective C-termini. In addition, we find that the proper localization of
the beta- dystroglycan is dependent upon both Dp260 at the OPL and Dp71
expression at the ILM. Thus, Dp260 and Dp71 are non-redundant isoforms that
are located at different sites within the retina yet have a common
interaction with beta-dystroglycan. Our data suggest that both Dp71 and
Dp260 contribute distinct but essential roles to retinal electrophysiology.
|
| |
Keywords: | |
本文献已被 Oxford 等数据库收录! |
|