GAPDH was subsequently identified on the surface

of other Gram-positive bacteria including staphylococci [11, 12], S. agalactiae [13], S. pneumoniae [14] and Listeria monocytogenes [15]. In addition, surface localization of GAPDH has been reported in enterohemorrhagic (EHEC) and enteropathogenic (EPEC) Escherichia coli; the protein of these pathogens has been observed to bind to human plasminogen and fibrinogen, suggesting a role in pathogenesis [16]. Similar to the surface-localized GAPDHs from other species, the EHEC and EPEC GAPDH proteins possess NAD-ribosylating activity [17]. In Mycoplasma see more genitalium, surface-associated GAPDH is important for adhesion to human mucin [18], and in Lactobacillus plantarum, a normal inhabitant of the human gastrointestinal tract, GAPDH was shown to be involved in adherence to gastric mucin and Caco-2 cells [19, 20]. Interestingly, the major fimbriae of Porphyromonas gingivalis bind to GAPDH on the surface of several oral streptococci, and this interaction is important for colonization of the oral cavity [21]. Fungi also express GAPDH on their cell surface, for example, the

GAPDH of Candida albicans was shown to be associated with the cell wall and involved in mediating adhesion to fibronectin, laminin and plasminogen [22–24]. GAPDH has also been found on the surface of the single-celled protozoan, Trichomonas vaginalis, and shown to bind extracellular matrix components, including fibronectin [25]. The N. meningitidis MC58 genome sequence contains two selleck chemicals putative GAPDH-encoding

genes (gapA-1 and gapA-2) which share 50% nucleotide identity [26]. Expression of GapA-1 (but not GapA-2) on the meningococcal cell surface was previously found to be up-regulated following contact with human epithelial cells, although no function was ascribed to this observation [27]. Two other cytoplasmic glycolytic enzymes, despite lacking identifiable secretion signals, anchoring motifs or hydrophobic membrane-spanning regions (hence the term ‘anchorless proteins’), have been found localized to the surface of N. meningitidis. These are enolase, which acts to recruit plasminogen onto the bacterial surface [28], and fructose-1, 6-bisphosphate aldolase (FBA), which we have recently demonstrated is required for optimal adhesion to human cells [29]. The aim of this study was to determine whether GapA-1 can influence DOK2 the interaction of meningococci and host cells. Methods Bacterial strains and growth conditions E. coli TOP10F’ and BL21(DE3)pLysS (Table 1) were used for the expression of 6 × histidine-tagged recombinant GapA-1 encoded by plasmid pDT-GapA1 (Table 1). E. coli JM109 was used as host for the construction of mutagenic and complementation plasmids, pSAT-8 and pSAT-14 respectively. E. coli strains were grown at 37°C in LB broth or on LB agar supplemented, where appropriate, with ampicillin (100 μg ml-1), kanamycin (30 μg ml-1) or erythromycin (200 μg ml-1).