Single-Cell and Single-Molecule Analysis Unravels the Multifunctionality of the Staphylococcus aureus Collagen-Binding Protein Cna.
The collagen-binding protein Cna is a prototype cell surface protein from Staphylococcus aureus which fulfils important physiological functions during pathogenesis. While it is established that Cna binds to collagen (Cn) via the high-affinity collagen hug mechanism, whether this protein is engaged in other ligand-binding mechanisms is poorly understood. Here, we use atomic force microscopy to demonstrate that Cna mediates attachment to two structurally and functionally different host proteins, i.e., the complement system protein C1q and the extracellular matrix protein laminin (Lam), through binding mechanisms that differ from the collagen hug. We show that single Cna-C1q and Cna-Lam bonds are much weaker than the high-affinity Cna-Cn bond and that their formation does not require the B-region of Cna. At the whole cell level, we find that bacterial adhesion to C1q-substrates involves only one (or two) molecular bond(s), while adhesion to Lam is mediated by multiple bonds, thus suggesting that multivalent or cooperative interactions may enhance the strength of adhesion. Both C1q and Lam interactions can be efficiently blocked by monoclonal antibodies directed against the minimal Cn-binding domain of Cna. These results show that Cna is a multifunctional protein capable of binding to multiple host ligands through mechanisms that differ from the classical collagen hug.
Institute of Life Sciences, Université Catholique de Louvain , Croix du Sud, 4-5, bte L7.07.06, Louvain-la-Neuve B-1348, Belgium.
Claire
C
Valotteau
Institute of Life Sciences, Université Catholique de Louvain , Croix du Sud, 4-5, bte L7.07.06, Louvain-la-Neuve B-1348, Belgium.
Valeria
V
Prystopiuk
Department of Molecular Medicine, Unit of Biochemistry, University of Pavia , Viale Taramelli 3/b, Pavia 27100, Italy.
Giampiero
0000-0002-7069-8155
G
Pietrocola
Department of Molecular Medicine, Unit of Biochemistry, University of Pavia , Viale Taramelli 3/b, Pavia 27100, Italy.
Simonetta
S
Rindi
Laboratory of Protein Chemistry, Department of Pharmaceutical and Pharmacological Sciences, University of Padua , via F. Marzolo 5, Padova 35131, Italy.
Daniele
D
Peterle
Laboratory of Protein Chemistry, Department of Pharmaceutical and Pharmacological Sciences, University of Padua , via F. Marzolo 5, Padova 35131, Italy.
Vincenzo
V
De Filippis
Department of Microbiology, Trinity College Dublin , Dublin 2, Ireland.
Timothy J
TJ
Foster
Department of Molecular Medicine, Unit of Biochemistry, University of Pavia , Viale Taramelli 3/b, Pavia 27100, Italy.
Pietro
P
Speziale
Institute of Life Sciences, Université Catholique de Louvain , Croix du Sud, 4-5, bte L7.07.06, Louvain-la-Neuve B-1348, Belgium.|Walloon Excellence in Life sciences and Biotechnology (WELBIO) , Liège 4000, Belgium.
Yves F
0000-0002-7289-4248
YF
Dufrêne
D018829:Adhesins, Bacterial / Q000737:chemistry / Q000378:metabolism*; D002448:Cell Adhesion; D018625:Microscopy, Atomic Force; D000072760:Single Molecule Imaging; D059010:Single-Cell Analysis; D013211:Staphylococcus aureus / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism; D020349:Surface Plasmon Resonance
D018829:Adhesins, Bacterial; C048165:adhesin, Staphylococcus aureus
C1q; Cna; Staphylococcus aureus; atomic force microscopy; binding mechanisms; force spectroscopy; laminin