Claudin-19
1_MANSG 6_ LQLLG 11_ YFLAL 16_ GGWVG 21_ IIAST 26_ ALPQW 31_ KQSSY 36_ AGDAI 41_ ITAVG 46_ LYEGL 51_ WMSCA 56_ SQSTG 61_ QVQCK 66_ LYDSL 71_ LALDG 76_ HIQSA 81_ RALMV 86_ VAVLL 91_ GFVAM 96_ VLSVV 101_ GMKCT 106_ RVGDS 111_ NPIAK 116_ GRVAI 121_ AGGAL 126_ FILAG 131_ LCTLT 136_ AVSWY 141_ ATLVT 146_ QEFFN 151_ PSTPV 156_ NARYE 161_ FGPAL 166_ FVGWA 171_ SAGLA 176_ VLGGS 181_ FLCCT 186_ CPEPE 191_ RPNSS 196_ PQPYR 201_ PGPSA 206_ AAREP 211_ VVKLP 216_ASAKG
1: Forms paracellular channels: coassembles with CLDN16 into tight junction strands with cation-selective channels through the strands, conveying epithelial permeability in a process known as paracellular tight junction permeability (PubMed:18188451, PubMed:28028216). Involved in the maintenance of ion gradients along the nephron. In the thick ascending limb (TAL) of Henle's loop, facilitates sodium paracellular permeability from the interstitial compartment to the lumen, contributing to the lumen-positive transepithelial potential that drives paracellular magnesium and calcium reabsorption (By similarity) (PubMed:17033971, PubMed:25555744). Forms paracellular barriers on its own. In the peripheral nervous system, represents a major constituent of the tight junctions in Schwann cells and contributes to electrical sealing. During retinal neurogenesis, may regulate the barrier properties of tight junctions in retinal pigment epithelium, required for proper retinal tissue differentiation and vision (By similarity) (PubMed:17033971, PubMed:30937396)