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Research Database PMU-SQQUID

Evidence for a ternary interaction between alpha-actinin, (meta)vinculin and acidic-phospholipid bilayers.
Niggli, V; Gimona, M;
Eur J Biochem. 1993; 213(3): 1009-1015.
Originalarbeiten (Zeitschrift)

PMU-Authors

Gimona Mario

Abstract

The cytoskeletal component vinculin has been demonstrated by hydrophobic photoradiolabelling, to insert into bilayers containing acidic phospholipids and trace amounts of a photoactivatable analogue of lecithin. It is shown in this study that the higher-molecular-mass variant metavinculin and alpha-actinin, also share this property. alpha-Actinin and vinculin were also shown to associate with phosphatidylserine liposomes by chromatography of protein/lipid mixtures on a Bio-Gel A-5m column. Furthermore, interesting differences in the behaviour of binary mixtures of these proteins, in the presence of phosphatidylserine liposomes, are shown. Thus, incubation of alpha-actinin with vinculin or metavinculin, prior to the addition of liposomes, strongly inhibited the photoradiolabelling of alpha-actinin under conditions in which the liposome surface was non-limiting, but enhanced the labelling of vinculin. In contrast, vinculin and metavinculin did not mutually influence their labelling. Using gel-filtration chromatography, it was shown that alpha-actinin still bound to the vinculin-liposome complex, under conditions similar to those used for hydrophobic photolabelling with a non-limiting lipid surface. In the presence of limiting amounts of liposomes, the alpha-actinin/vinculin ratio was markedly decreased in the liposome fractions. Our results suggest the formation of a ternary complex consisting of vinculin, alpha-actinin and phospholipids. In this complex, both proteins interact at the bilayer, resulting in an altered conformation of the two proteins and, as a consequence, in modified bilayer interactions.


Useful keywords (using NLM MeSH Indexing)

Actinin/analysis

Actinin/chemistry*

Animals

Chromatography, Gel

Lipid Bilayers/chemistry*

Liposomes/analysis

Muscle Proteins/chemistry*

Phospholipids/chemistry

Swine

Vinculin/analysis

Vinculin/chemistry*