Involved in alveolar fluid homeostasis via regulation of alveolar epithelial tight junction composition and therefore ion transport and solute permeability, potentially via downstream regulation of the actin cytoskeleton organization and beta-2-adrenergic signaling (By similarity). Required for lung alveolarization and maintenance of the paracellular alveolar epithelial barrier (By similarity). Acts to maintain epithelial progenitor cell proliferation and organ size, via regulation of YAP1 localization away from the nucleus and thereby restriction of YAP1 target gene transcription (By similarity). Acts as a negative regulator of RANKL-induced osteoclast differentiation, potentially via relocation of TJP2/ZO-2 away from the nucleus, subsequently involved in bone resorption in response to calcium deficiency (By similarity). Mediates the osteoprotective effects of estrogen, potentially via acting downstream of estrogen signaling independently of RANKL signaling pathways (By similarity).
Involved in the maintenance of homeostasis of the alveolar microenvironment via regulation of pH and subsequent T-cell activation in the alveolar space, is therefore indirectly involved in limiting C. neoformans infection.
Required for the formation of the gastric paracellular barrier via its role in tight junction formation, thereby involved in the response to gastric acidification.
Subcellular locations: Cell junction, Tight junction, Cell membrane
Localizes to tight junctions in epithelial cells.
Subcellular locations: Cell junction, Tight junction
Subcellular locations: Cell junction, Tight junction, Lateral cell membrane
Expression is restricted to the lung.
Expression is restricted to the stomach mucosa where it is predominantly observed in the epithelial cells of the pit region and the base of the gastric glands including exocrine and endocrine cells (at protein level).