MULTIPLE BETA-1-CHAIN INTEGRINS ARE RECEPTORS FOR INVASIN, A PROTEIN THAT PROMOTES BACTERIAL PENETRATION INTO MAMMALIAN-CELLS

Mammalian cell receptors that promote entry of intracellular bacteria into nonphagocytic cells have not been identified. We show here that multiple members of the integrin superfamily of cell adhesion receptors bind the Y. pseudotuberculosis invasin protein prior to bacterial penetration into mammalian cells. Affinity chromatography of crude detergent extracts demonstrated that integrins containing the subunit structures α3β1, α4β1, α5β1, and α6β1 bound to immobilized invasin. Furthermore, phospholipid vesicles containing isolated integrin proteins were able to attach to invasin. Specificity for invasin binding to the identified integrin receptors was also demonstrated, as immunoprobing and phospholipid reconstitution studies showed that the α2β1 integrin, β2 chain integrins, and vitronectin receptor (αvβ3) were not involved in cellular attachment to invasin. © 1990.