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Fibronectin potentiates actin polymerization in thrombin-activated platelets.

C S Cierniewski·J Karczewski·M A Kowalska
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Abstract

The effect of fibronectin on the polymerization state of actin was studied. Triton X-100-insoluble cytoskeleton was prepared from thrombin-activated platelets, and the conversion of G-actin into F-actin was monitored by an assay involving DNase I inhibition by G-actin. It was found that fibronectin bound to membrane receptors decreased the level of platelet G-actin. This observation suggests that in the presence of fibronectin a larger amount of F-actin becomes incorporated into the Triton X-100-insoluble cytoskeleton. At the same molar concentration, fibrinogen only slightly increased actin polymerization, whereas bovine serum albumin at a much higher concentration caused a small inhibition of actin immobilization. Our data show that fibronectin, through interaction with the platelet actomyosin fibrillar system, facilitates actin polymerization into the cytoskeleton.

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ActinsBlood PlateletsCell MembraneCytochalasin BCytoskeletonDeoxyribonuclease IDrug SynergismFibronectinsHumansImmunologic TechniquesMacromolecular SubstancesThrombinJournal Article

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C S Cierniewski, J Karczewski, M A Kowalska. 1986. Fibronectin potentiates actin polymerization in thrombin-activated platelets.. https://doi.org/10.1002/jcb.240300108

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