InlB, a cell wall protein of Listeria monocytogenes, binds MET receptor, acting as an HGF agonist (Shen et al. 2000, Veiga and Cossart 2005). Listeria monocytogenes InlB proteins dimerize through their leucine-rich repeat regions (LRRs), promoting dimerization of MET receptors that they are bound to (Ferraris et al. 2010). InlB-induced MET receptor dimerization is followed by MET trans-autophosphorylation and activation of downstream RAS/RAF/MAPK signaling and PI3K/AKT signaling (Niemann et al. 2007, Ferraris et al. 2010). InlB-bound phosphorylated MET receptor recruits the E3 ubiquitin ligase CBL through GRB2. CBL-mediated monoubiquitination of InlB-bound MET promotes endocytosis and entry of Listeria monocytogenes to host cells (Veiga and Cossart 2005). CIN85 is necessary for endocytosis-mediated entry of Listeria monocytogenes triggered by CBL-mediated monoubiquitination of MET (Veiga and Cossart 2005). Proteins involved in clathrin-mediated endocytosis EPS15 and HGS (Hrs) are both necessary for CBL and MET-mediated entry of Listeria monocytogenes into host cells (Veiga and Cossart 2005).
A potential coreceptor role of CD44 in InlB-mediated MET activation is contradictory (Jung et al. 2009, Dortet et al. 2010).