Abstract
In this report, we investigated the lateral diffusion of transforming growth factor beta (TGF-beta) type I receptor (TbetaRI) in living cells by imaging and tracking individual green fluorescent protein tagged TbetaRI on the cell membrane. We found that when co-expressed with TGF-beta type II receptor (TbetaRII), the mobility of TbetaRI decreased significantly after TGF-beta1 stimulation. However, in the cells that had been depleted of cholesterol with Nystatin or methyl-beta-cyclodextrin, the diffusion rate of TbetaRI was not changed by TGF-beta1 treatment. Our observations suggest that membrane lipid-rafts provide an environment that facilitates the association of TbetaRI and TbetaRII for cell signaling.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Activin Receptors, Type I / genetics
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Activin Receptors, Type I / metabolism*
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Cell Membrane / drug effects
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Cell Membrane / metabolism
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Green Fluorescent Proteins / genetics
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Green Fluorescent Proteins / metabolism*
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HeLa Cells
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Humans
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Ionophores / pharmacology
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Membrane Microdomains / drug effects
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Membrane Microdomains / metabolism
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Microscopy, Fluorescence / methods*
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Nystatin / pharmacology
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Protein Serine-Threonine Kinases
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Protein Transport / drug effects
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Receptor, Transforming Growth Factor-beta Type I
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Receptor, Transforming Growth Factor-beta Type II
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Receptors, Transforming Growth Factor beta / genetics
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Receptors, Transforming Growth Factor beta / metabolism*
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Transforming Growth Factor beta1 / pharmacology
Substances
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Ionophores
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Receptors, Transforming Growth Factor beta
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Transforming Growth Factor beta1
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Nystatin
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Green Fluorescent Proteins
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Protein Serine-Threonine Kinases
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Activin Receptors, Type I
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Receptor, Transforming Growth Factor-beta Type I
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Receptor, Transforming Growth Factor-beta Type II