Characterization of group B streptococcal glyceraldehyde-3-phosphate dehydrogenase: surface localization, enzymatic activity, and protein–protein interactions

Abstract

During characterization of the surface antigens of serotype III group B streptococci (GBS), a protein with an apparent M(r) of approximately 173,500 migrating on a SDS--polyacrylamide gel was found to have an N-terminal amino acid sequence identical to that of the plasmin receptor (Plr) of group A streptococci, a surface-localized glyceraldehyde-3-phosphate dehydrogenase (GAPDH). This work begins to characterize GBS GAPDH and to assess its functional activity on the cell surface. The 1.0-kb gapC gene of GBS was amplified by PCR. plr and gapC demonstrated 87% homology. An anti-Plr monoclonal antibody reacted with GBS whole cells, suggesting GBS GAPDH is surface localized. Multiple serotypes of GBS demonstrated functional GAPDH on their surfaces. The anti-Plr monoclonal antibody recognized GBS protein bands of approximately 41 and 173.5 kDa, by Western blot. Presumably, these represent monomeric and tetrameric forms of the GAPDH molecule. GBS GAPDH was demonstrated by Western blot analysis to interact with lys- and glu-plasminogens. Fluid-phase GBS GAPDH interacted, by means of ELISA, with immobilized lys-plasminogen, glu-plasminogen, actin, and fibrinogen. Enzymatically active GAPDH, capable of binding cytoskeletal and extracellular matrix proteins, is expressed on the surface of GBS.

LAP, an alcohol acetaldehyde dehydrogenase enzyme in Listeria, promotes bacterial adhesion to enterocyte-like Caco-2 cells only in pathogenic species

“…Metabolic or housekeeping enzymes that serve as adhesion/ invasion factors are often referred to as 'anchorless adhesins' (Pancholi & Chhatwal, 2003;Scott & Barnett, 2006) and the mechanism by which they interact with the cell wall is not well understood. Glyceraldehyde-3-phosphate dehydrogenase, present on the cell surface in group III streptococci (Seifert et al, 2003) and C. albicans (GilNavarro et al, 1997) serves as a virulence factor. Similarly, alcohol acetaldehyde dehydrogenase found on the surface of only pathogenic strains of E. histolytica, not in nonpathogenic strains, serves as an adhesion factor (Torian et al, 1990).…”

“…Participation of metabolic or housekeeping enzymes in pathogenic functions is not unprecedented (Pancholi & Chhatwal, 2003). In group III streptococci (Seifert et al, 2003) and Candida albicans (Gil-Navarro et al, 1997), glyceraldehyde-3-phosphate dehydrogenase is expressed on the cell surface and serves as a virulence factor. In Entamoeba histolytica, alcohol acetaldehyde dehydrogenase is an adhesion factor that is present primarily in pathogenic strains, but is absent or present in trace amounts in six non-pathogenic strains (Torian et al, 1990).…”

Secretion of the housekeeping protein glyceraldehyde-3-phosphate dehydrogenase by the LEE-encoded type III secretion system in enteropathogenic Escherichia coli

“…In bacteria, nonglycolytic GAPDH functions have been associated with its extracellular location. GAPDH is one of the housekeeping proteins secreted by pathogens that interact with different host components, being involved in adhesion and/or virulence (Alvarez-Dominguez et al, 2008;Jin et al, 2005;Lama et al, 2009;Pancholi and Chhatwal, 2003;Schaumburg et al, 2004;Seifert et al, 2003;Terao et al, 2006).…”

Interaction with human plasminogen system turns on proteolytic activity in Streptococcus agalactiae and enhances its virulence in a mouse model

“…The GBS GAPDH is a moonlighting protein which, when present at the cell surface, interacts with cytoskeleton and extracellular matrix proteins and Plg [17]. This bacterium also expresses a Fg receptor named FbsA that binds to human Fg [18].…”