Two-Photon Imaging of NADH in SKH1 Mice Reveals Changes in Keratinocyte Metabolism with Chronic UVA Exposure

Abstract

we utilize single-molecule microscopy to localize and track fluorescently labeled chaperone and effector proteins in live Yersinia enterocolitica cells, a human pathogen in which the three phases of secretion can be physically and chemically controlled. By combining single-molecule tracking with bacterial genetics, we determine the prevalent diffusive states of chaperone proteins and chaperone:effector protein complexes in the presence and absence of their (putative) cytosolic binding partners. The results allow us to test whether the temporal hierarchy of secretion is regulated by cytosolic T3SS components that interact with chaperone:effector substrates either at the injectisome or while diffusing freely in the cytosol. Understanding the mechanism of temporally-ordered secretion may reveal new strategies for targeted anti-virulence therapies and enable the controlled use of T3SSs for therapeutic purposes.