P. micra surface protein TmpC interacts directly with OSCC cell lines via CKAP4, a receptor frequently overexpressed in human OSCC tumors. The interaction of TmpC and CKAP4 mediates bacterial attachment, invasion, and metastasis-promoting effects of P. micra on OSCC and subsequently activates HIF-1α and autophagy signaling, via CKAP4-RanBP2 and CKAP4-NBR1 interaction, respectively.