title: Covalent binding of lipids to cytoskeletal proteins of mouse mammary epithelial cells.
abstract: Cytoskeletal proteins obtained from mouse mammary epithelial cells (MMEC) were found to be modified by covalent attachment of lipids. Primary cultures of MMEC were incubated in the presence of 3H-palmitate for 4 h. A cytoskeletal (CS) fraction was prepared by treatment of the cells with 1.5M KCl and 1% Triton X-100. The residual material, consisting primarily of keratin and actin filaments was exhaustively (10-20 rounds, including sonications) extracted with chloroform/methanol to remove non-covalently bound labeled lipids. The CS protein was then acid-hydrolyzed and the chloroform-soluble products subjected to thin layer chromatography (TLC). Two-thirds of the covalently bound radiolabel appeared as a very hydrophobic peak on a TLC system optimized for separation of neutral lipids. Ten percent separated into 4-5 peaks on a polar lipid TLC system. A small amount of label was traced to fatty acid-like components. Autoradiography of two-dimensional gels indicated that all the CS proteins resolvable by Coomassie blue staining were also radiolabeled. The results are discussed in terms of CS-lipid-membrane interactions.
authors.affiliation: Department of Experimental Pathology, Roswell Park Cancer Institute, Buffalo, NY 14263.
authors.forename: H L
authors.initials: HL
authors.lastname: Asch
authors.forename: E
authors.initials: E
authors.lastname: Mayhew
authors.forename: T
authors.initials: T
authors.lastname: Hennessey
authors.forename: R O
authors.initials: RO
authors.lastname: Lazo
authors.forename: B B
authors.initials: BB
authors.lastname: Asch
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002855:Chromatography, Thin Layer; D003598:Cytoskeletal Proteins / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D008321:Mammary Glands, Animal / Q000378:metabolism*; D008563:Membrane Lipids / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D010168:Palmitates / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D014316:Tritium
chemical_list: D003598:Cytoskeletal Proteins; D008563:Membrane Lipids; D010168:Palmitates; D014316:Tritium