1.H.1.1.12
Claudin-15 of 227 aas and 4 TMSs, Cldn15.  Suzuki et al. 2013 reported the crystal structure of mouse claudin-15 at a resolution of 2.4 angstroms. The structure revealed a characteristic β-sheet fold consisting of two extracellular segments anchored to a transmembrane four-helix bundle by a consensus motif. Potential paracellular pathways with distinctive charges on the extracellular surface provided insight into the molecular basis of ion homeostasis across tight junctions. Site-specific distributions of claudin-2- and claudin-15-based paracellular channels drive their organ-specific functions in the liver, kidney, and intestine (Tanaka et al. 2017). A model of the claudin-15-based paracellular channel has been presented (Alberini et al. 2017).