Predicted expansion of the claudin multigene family

Abstract

Claudins (Cldn) are essential membrane proteins of tight junctions (TJs), which form the paracellular permselective barrier. They are produced by a multi-gene family of 24 reported members in mouse and human. Based on a comprehensive search combined with phylogenetic analyses, we identified three novel claudins (claudin-25, -26, and -27). Quantitative RT-PCR revealed that the three novel claudins were expressed in a tissue- and/or developmental stage-dependent manner. Claudins-25 and -26, but not claudin-27, were immunofluorescently localized to TJs when exogenously expressed in cultured MDCK and Eph epithelial cell lines. These findings expand the claudin family to include at least 27 members.

Deletion of claudin-10 ( Cldn10 ) in the thick ascending limb impairs paracellular sodium permeability and leads to hypermagnesemia and nephrocalcinosis

“…The paracellular passage is largely controlled by the tight junction (TJ), a supramolecular structure of membrane-spanning proteins, their intracellular adapters, and scaffolding proteins (3). Claudins, a family comprising 27 members (4), are the main components of the TJ defining the permeability properties. They interact via their extracellular loops with corresponding claudins of the neighboring cell to allow or restrict passage of specific solutes (5,6).…”

Blood–testis barrier and Sertoli cell function: lessons from SCCx43KO mice

“…Nevertheless, BTB establishment is not solely dependent upon OCCLUDIN indicating a much more complex composition and function (Schulzke et al 2005). As of 2011 (Mineta et al 2011), 23 different CLAUDIN proteins have been discovered so far. These various CLAUDINs are considered to be seal or barrier specific (Gü nzel & Yu 2013), with CLAUDIN3 (Meng et al 2005), CLAUDIN5 (Morrow et al 2009), and CLAUDIN11 (Gow et al 1999, Morita et al 1999 being associated with murine BTB formation (Morrow et al 2010).…”

Lecture

“…Claudins (CLDNs) are tetraspan proteins consisting of a family with at least 26 members, [5][6][7] ranging in molecular mass from 20-28 kD. Claudins have four transmembrane domains, two extracellular loops, amino-and C-terminal cytoplasmic domains and a short cytoplasmic turn (Fig.…”