期刊
AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY
卷 284, 期 6, 页码 C1346-C1354出版社
AMER PHYSIOLOGICAL SOC
DOI: 10.1152/ajpcell.00547.2002
关键词
tight junction; claudin-4; claudin-2; dilution potential; intercellular junction; transepithelial electrical resistance
资金
- NIDDK NIH HHS [DK-55389, DK-38979, DK-61283] Funding Source: Medline
- PHS HHS [DL-34989, DL-45134] Funding Source: Medline
Tight junctions ( TJs) regulate paracellular permeability across epithelia and vary widely in their transepithelial electrical resistance (TER) and charge selectivity. The claudin family of transmembrane proteins influences these properties. We previously reported that claudin-4 increased TER similar to300% when expressed in low-resistance Madin-Darby canine kidney (MDCK) II cells and decreased the paracellular permeability for Na+ more than Cl- ( Van Itallie C, Rahner C, and Anderson JM. J Clin Invest 107: 1319 - 1327, 2001). In comparison, we report here that expression of claudin-2 increases TER by only similar to20% and does not change the ionic selectivity of MDCK II cells from their cation-selective background. To test whether the extracellular domains of claudins-4 and - 2 determine their unique paracellular properties, we determined the effects of interchanging these domains between claudins-4 and - 2. Inducible expression of wild-type claudins and extracellular domain chimeras increased both the number and depth of fibrils, but the characteristic fibril morphologies of claudin-4 or - 2 were not altered by switching extracellular domains. Like claudin-4, chimeras expressing the first or both extracellular domains of claudin-4 on claudin-2 increased TER severalfold and profoundly decreased the permeability of Na+ relative to Cl-. In contrast, chimeras expressing the first or both extracellular domains of claudin-2 on claudin-4 increased the TER by only similar to60 and similar to40%, respectively, and only modestly altered charge selectivity. These results support a model in which the claudins create paracellular channels and the first extracellular domain is sufficient to determine both paracellular charge selectivity and TER.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据