The ABCA1 cholesterol transporter associates with one of two distinct dystrophin-based scaffolds in Schwann cells.
Cytoskeletal scaffolding complexes help organize specialized membrane domains with unique functions on the surface of cells. In this study, we define the scaffolding potential of the Schwann cell dystrophin glycoprotein complex (DGC) by establishing the presence of four syntrophin isoforms, (alpha1, beta1, beta2, and gamma2), and one dystrobrevin isoform, (alpha-dystrobrevin-1), in the abaxonal membrane. Furthermore, we demonstrate the existence of two separate DGCs in Schwann cells that divide the abaxonal membrane into spatially distinct domains, the DRP2/periaxin rich plaques and the Cajal bands that contain Dp116, utrophin, alpha-dystrobrevin-1 and four syntrophin isoforms. Finally, we show that the two different DGCs can scaffold unique accessory molecules in distinct areas of the Schwann cell membrane. Specifically, the cholesterol transporter ABCA1, associates with the Dp116/syntrophin complex in Cajal bands and is excluded from the DRP2/periaxin rich plaques.
Albrecht
Douglas E
DE
Department of Physiology and Biophysics, University of Washington, 1959 NE Pacific St, Box 357290, Seattle WA 98195-7290, USA
Sherman
Diane L
DL
Brophy
Peter J
PJ
Froehner
Stanley C
SC
D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D000818:Animals; D002135:Calcium-Binding Proteins / Q000172:deficiency; D002462:Cell Membrane / Q000378:metabolism*; D016189:Dystrophin / Q000502:physiology*; D049029:Dystrophin-Associated Proteins / Q000172:deficiency; D047468:Immunoprecipitation / Q000379:methods; D008565:Membrane Proteins / Q000172:deficiency; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008954:Models, Biological; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000172:deficiency; D051381:Rats; D017208:Rats, Wistar; D012583:Schwann Cells / Q000648:ultrastructure*; D012584:Sciatic Nerve / Q000166:cytology
D064286:ATP Binding Cassette Transporter 1; D018528:ATP-Binding Cassette Transporters; D002135:Calcium-Binding Proteins; D016189:Dystrophin; D049029:Dystrophin-Associated Proteins; D008565:Membrane Proteins; D009124:Muscle Proteins; C091824:syntrophin; C091825:syntrophin alpha1