Role of cdGMP in Francisella novicida biofilm formation

dc.contributor.advisorKlose, Karl E.
dc.contributor.authorWyatt, Geoffrey
dc.contributor.committeeMemberSeshu, Janakiram
dc.contributor.committeeMemberGuentzel, Neal
dc.descriptionThis item is available only to currently enrolled UTSA students, faculty or staff. To download, navigate to Log In in the top right-hand corner of this screen, then select Log in with my UTSA ID.
dc.description.abstract<italic>Francisella tularensis</italic> is a gram-negative intracellular pathogen that is highly virulent in humans causing the disease tularemia. <italic>F. novicida</italic> is closely-related to <italic>F. tularensis</italic> but is avirulent in humans. Within a cluster of six genes that is specific to <italic>F. novicida</italic> are two genes, <italic>cdgA</italic> and <italic>cdgB</italic>, that encode proteins with diguanylate cyclase (DGC) and phosphodiesterase (PDE) domains. The <italic>F. tularensis</italic> genome does not encode any DGC or PDE containing proteins. DGCs and PDEs modulate the synthesis and degradation of cyclic di-GMP (cdGMP). cdGMP is a signaling molecule involved in the shift between planktonic and biofilm growth phases. An <italic>F. novicida</italic> mutant strain lacking both <italic>cdgA</italic> and <italic>cdgB</italic> is defective for biofilm formation. Although they contain both CDG and PDE domains, biofilm studies suggest that CdgA acts primarily as a PDE, while CdgB acts primarily as a DGC. Expressing CdgB from a plasmid stimulates <italic>F. novicida</italic> biofilm formation, even in a strain lacking the biofilm regulator <italic>qseB</italic>. qRT-PCR analysis confirmed that QseB regulates <italic>cdgA</italic> and <italic>cdgB</italic> transcription, suggesting a signaling cascade controlling cdGMP levels. We suggest that differences in cdGMP signaling may contribute to the relative virulence of <italic>Francisella</italic> species.
dc.description.departmentIntegrative Biology
dc.format.extent32 pages
dc.titleRole of cdGMP in Francisella novicida biofilm formation
dcterms.accessRightspq_closed Biology of Texas at San Antonio of Science


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