Open AccessClaudin-4 reconstituted in unilamellar vesicles is sufficient to form tight interfaces that partition membrane proteins
Author(s) -
Brian Belardi,
Sungmin Son,
Michael D. Vahey,
Jinzhi Wang,
Jianghui Hou,
Daniel A. Fletcher
Publication year - 2018
Publication title -
journal of cell science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.384
H-Index - 278
eISSN - 1477-9137
pISSN - 0021-9533
DOI - 10.1242/jcs.221556
Subject(s) - tight junction , claudin , vesicle , biology , microbiology and biotechnology , membrane , transmembrane protein , epithelial polarity , septate junctions , membrane protein , biophysics , intracellular , biochemistry , gap junction , receptor
Tight junctions have been hypothesized to act as molecular fences in the plasma membrane of epithelial cells, helping to form differentiated apical and basolateral domains. While this fence function is believed to arise from the interaction of four-pass transmembrane claudins, the complexity of tight junctions has made direct evidence of their role as a putative diffusion barrier difficult to obtain. Here we address this challenge by reconstituting claudin-4 into giant unilamellar vesicles using microfluidic jetting. We find that reconstituted claudin-4 is sufficient to form adhesive membrane interfaces without accessory proteins present in vivo. By controlling the molecular composition of the inner and outer leaflets of jetted vesicle membranes, we show that claudin-4-mediated interfaces can drive partitioning of extracellular membrane proteins with ectodomains as small as 5 nm but not of inner or outer leaflet lipids. Our findings indicate that homotypic interactions of claudins and their small size can contribute to the polarization of epithelial cells.