Single-molecular-level study of claudin-1-mediated adhesion.
Claudins are proteins that are selectively expressed at tight junctions (TJs) of epithelial cells where they play a central role in regulating paracellular permeability of solutes across epithelia. However, the role of claudins in intercellular adhesion and the mechanism by which they regulate the diffusion of solutes are poorly understood. Here, using single molecule force spectroscopy, the kinetic properties and adhesion strength of homophilic claudin-1 interactions were probed at the single-molecule level. Within the range of tested loading rates (10(3)-10(5) pN/s), our results showed that homophilic claudin-1 interactions have a reactive compliance of 0.363 +/- 0.061 nm and an unstressed dissociation rate of 1.351 +/- 1.312 s-1. This is more than 100-fold greater than that of E-cadherin. The weak and short-lived interactions between claudin-1 molecules make them highly unstable and dynamic in nature. Such a dynamic interaction is consistent with a model where breaking and resealing of TJ strands regulate the paracellular diffusion of solutes.
Lim
Tong Seng
TS
Bioinformatics Institute, A*STAR (Agency for Science, Technology and Research), 30 Biopolis Street, Singapore 138671.
Vedula
Sri Ram Krishna
SR
Kausalya
P Jaya
PJ
Hunziker
Walter
W
Lim
Chwee Teck
CT
D002448:Cell Adhesion / Q000502:physiology*; D062445:Claudin-1; D007700:Kinetics; D008565:Membrane Proteins / Q000502:physiology*; D018625:Microscopy, Atomic Force; D009010:Monte Carlo Method
D062445:Claudin-1; D008565:Membrane Proteins