Abstract
In striated muscle, the plasma membrane forms tubular invaginations (transverse tubules or T-tubules) that function in depolarization-contraction coupling. Caveolin-3 and amphiphysin were implicated in their biogenesis. Amphiphysin isoforms have a putative role in membrane deformation at endocytic sites. An isoform of amphiphysin 2 concentrated at T-tubules induced tubular plasma membrane invaginations when expressed in nonmuscle cells. This property required exon 10, a phosphoinositide-binding module. In developing myotubes, amphiphysin 2 and caveolin-3 segregated in tubular and vesicular portions of the T-tubule system, respectively. These findings support a role of the bilayer-deforming properties of amphiphysin at T-tubules and, more generally, a physiological role of amphiphysin in membrane deformation.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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CHO Cells
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Caveolin 3
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Caveolins / metabolism
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Cell Differentiation
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Cell Line
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Cell Membrane / metabolism
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Cell Membrane Structures / metabolism
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Cell Membrane Structures / ultrastructure*
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Cricetinae
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Dynamins
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Exons
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GTP Phosphohydrolases / metabolism
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Liposomes / metabolism
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Mice
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Microscopy, Electron
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Morphogenesis
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Muscle Development*
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Muscle, Skeletal / metabolism
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Muscle, Skeletal / ultrastructure*
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Nerve Tissue Proteins / chemistry
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Nerve Tissue Proteins / genetics
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Nerve Tissue Proteins / metabolism*
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Phosphatidylinositol 4,5-Diphosphate / metabolism
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Protein Isoforms
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Protein Structure, Tertiary
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RNA, Small Interfering
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RNA, Untranslated / metabolism
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Recombinant Fusion Proteins / metabolism
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Transfection
Substances
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Cav3 protein, mouse
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Caveolin 3
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Caveolins
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Liposomes
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Nerve Tissue Proteins
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Phosphatidylinositol 4,5-Diphosphate
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Protein Isoforms
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RNA, Small Interfering
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RNA, Untranslated
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Recombinant Fusion Proteins
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amphiphysin
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GTP Phosphohydrolases
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Dynamins