Fibronectin potentiates actin polymerization in thrombin-activated platelets

✍ Scribed by Czeslaw S. Cierniewski; Jerzy Karczewski; Maria A. Kowalska

• Book ID: 102302577
• Publisher: John Wiley and Sons
• Year: 1986
• Tongue: English
• Weight: 376 KB
• Volume: 30
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.240300108

✦ Synopsis

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.