Pneumococcal proteins ClpC and UvrC as novel host plasminogen binding factors.

We identified two plasminogen binding proteins from a mouse which infected Streptococcus pneumoniae. The pneumococcal proteins were annotated as ClpC and UvrC using iTRAQ method. Recombinants of both proteins showed significant binding to plasminogen and were found to promote plasminogen activation by tissue-type plasminogen activator. In addition, ClpC and UvrC were LytA-dependently released into the culture supernatant and to bind to the bacterial surface. These results suggest that S. pneumoniae releases ClpC and UvrC by autolysis and recruits them to the bacterial surface, where they bind to plasminogen and promote its activation, contributing to extracellular matrix degradation and tissue invasion. This article is protected by copyright. All rights reserved.