Use of the Actinobacillus actinomycetemcomitans leukotoxin promoter

to drive expression of the Green Fluorescent Protein in an oral pathogen.

Joan E. Lippmann, Eunice H. Froeliger and Paula M. Fives-Taylor*

Department of Microbiology and Molecular Genetics, College of Medicine and College of Agriculture and Life Sciences, University of Vermont, Burlington, Vermont 05405

Keywords: Green Fluorescent Protein; Actinobacillus actinomycetemcomitans ; leukotoxin promoter; epithelial cell invasion.

Running short title: Expression of GFP in Aa

* corresponding author

email: pfivesta@zoo.uvm.edu

802-656-1121 telephone

802-656-8749 fax

ABSTRACT

The gene for the green fluorescent protein, gfp, was cloned, under the control of the Actinobacillus actinomycetemcomitans leukotoxin (ltx) promoter, in the A. actinomycetemcomitans shuttle vector, pSU20. A. actinomycetemcomitans containing the ltx-gfp construct emitted bright green fluorescence in the standard invasion assay using epifluorescence microscopy. These data demonstrate that the GFP will be a useful tool for the live analysis of A. actinomycetemcomitans interactions with host cells, and that the ltx promoter can be used to drive the expression of non-A. actinomycetemcomitans genes.

Actinobacillus actinomycetemcomitans, a gram negative, capnophillic organism, is strongly implicated as a causative agent for juvenile and adult periodontal disease - - - -- - -- "" - - - - '-- - - - -- - - - - - - -- - - - -- - -- - - - - - ' - ' - - - - - -

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