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Clathrin-coated vesicle assembly polypeptides: physical properties and reconstitution studies with brain membranes

The assembly polypeptides are an integral component of coated vesicles and may mediate the linkage of clathrin to the vesicle membrane. We have purified assembly polypeptides in milligram quantities from bovine brain by an improved procedure. Hydrodynamic and chemical crosslinking studies indicate t...

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Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1988
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2114949/
https://www.ncbi.nlm.nih.gov/pubmed/2892842
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description The assembly polypeptides are an integral component of coated vesicles and may mediate the linkage of clathrin to the vesicle membrane. We have purified assembly polypeptides in milligram quantities from bovine brain by an improved procedure. Hydrodynamic and chemical crosslinking studies indicate that the protein is an asymmetric heterotetramer with a molecular weight of 252,000, containing two subunits of Mr 98,000- 115,000, one subunit of 52,000, and one subunit of 16,000. Two- dimensional peptide maps of the subunits show that the 16- and 52-kD polypeptides are not derived from the higher molecular weight species, and that the group of bands at 98-115 kD are related. Electron microscopic visualization shows an essentially globular protein with one or two knob-like tails. We demonstrate a specific membrane protein binding site for 125I-labeled assembly polypeptides in 0.1 N sodium hydroxide-extracted bovine brain membranes based on the following criteria: (a) binding is displaceable by unlabeled ligand, (b) the binding site is destroyed by protease treatment of the membranes, and (c) the distribution of binding between vesicle-depleted membranes and coated vesicle membranes parallels the in vivo localization of assembly polypeptides and clathrin. This binding site is likely to be an integral membrane protein because (a) it is enriched in the sodium hydroxide-extracted membranes stripped of most of their peripheral membrane proteins, and (b) the binding site is partially extracted by 0.5% Triton X-100. A similar binding site appears to be present in coated vesicles. Clathrin binds to the hydroxide-stripped membranes in an assembly polypeptides dependent manner, and this binding is diminished by Triton extraction of the membranes. This assay may aid in identification of the membrane receptor for the assembly polypeptides.
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spelling pubmed-21149492008-05-01 Clathrin-coated vesicle assembly polypeptides: physical properties and reconstitution studies with brain membranes J Cell Biol Articles The assembly polypeptides are an integral component of coated vesicles and may mediate the linkage of clathrin to the vesicle membrane. We have purified assembly polypeptides in milligram quantities from bovine brain by an improved procedure. Hydrodynamic and chemical crosslinking studies indicate that the protein is an asymmetric heterotetramer with a molecular weight of 252,000, containing two subunits of Mr 98,000- 115,000, one subunit of 52,000, and one subunit of 16,000. Two- dimensional peptide maps of the subunits show that the 16- and 52-kD polypeptides are not derived from the higher molecular weight species, and that the group of bands at 98-115 kD are related. Electron microscopic visualization shows an essentially globular protein with one or two knob-like tails. We demonstrate a specific membrane protein binding site for 125I-labeled assembly polypeptides in 0.1 N sodium hydroxide-extracted bovine brain membranes based on the following criteria: (a) binding is displaceable by unlabeled ligand, (b) the binding site is destroyed by protease treatment of the membranes, and (c) the distribution of binding between vesicle-depleted membranes and coated vesicle membranes parallels the in vivo localization of assembly polypeptides and clathrin. This binding site is likely to be an integral membrane protein because (a) it is enriched in the sodium hydroxide-extracted membranes stripped of most of their peripheral membrane proteins, and (b) the binding site is partially extracted by 0.5% Triton X-100. A similar binding site appears to be present in coated vesicles. Clathrin binds to the hydroxide-stripped membranes in an assembly polypeptides dependent manner, and this binding is diminished by Triton extraction of the membranes. This assay may aid in identification of the membrane receptor for the assembly polypeptides. The Rockefeller University Press 1988-01-01 /pmc/articles/PMC2114949/ /pubmed/2892842 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Articles
Clathrin-coated vesicle assembly polypeptides: physical properties and reconstitution studies with brain membranes
title Clathrin-coated vesicle assembly polypeptides: physical properties and reconstitution studies with brain membranes
title_full Clathrin-coated vesicle assembly polypeptides: physical properties and reconstitution studies with brain membranes
title_fullStr Clathrin-coated vesicle assembly polypeptides: physical properties and reconstitution studies with brain membranes
title_full_unstemmed Clathrin-coated vesicle assembly polypeptides: physical properties and reconstitution studies with brain membranes
title_short Clathrin-coated vesicle assembly polypeptides: physical properties and reconstitution studies with brain membranes
title_sort clathrin-coated vesicle assembly polypeptides: physical properties and reconstitution studies with brain membranes
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2114949/
https://www.ncbi.nlm.nih.gov/pubmed/2892842