A ocludina é unha proteína que nos humanos está codificada polo xeneOCLN.[1][2]
É unha proteína integral de membrana de 65 kDa e 522 aminoácidos localizada nas unións herméticas que unen unhas células con outras. Foi descrita por primeira vez en 1993 por Shoichiro Tsukita.[3] Xunto coas proteínas claudinas, as ocludinas son os principais compoñentes das unións herméticas.
Segundo a hidrofilidade global da molécula, esta atravesa a membrana catro veces, formando dous bucles extracelulares e expoñendo no citosol os seus extremos N-terminal e C-terminal. A interacción da ocludina con varias proteínas citoplasmáticas da placa de unión ocorre polo seu extremo C-terminal, mentres que os bucles extracelulares crese que están implicados na regulación da permeabilidade paracelular e a adhesión celular. A fosforilación/desfosforilación xoga un papel fundamental na regulación da ocludina e das unións herméticas.
[4]
Os trastornos na regulación da ocludina son un importante aspecto de diversas doenzas, xa que se distorsionan as barreiras celulares. As estratexias para previr ou reverter esta regulación á baixa poden ser un importante recurso terapéutico. Está implicada en diarreas, cancro, doenzas inflamatorias, alerxias, diabetes, esclerose múltiple, entre outras.[4]
↑Peng, Bi-Hung; Lee J Ching; Campbell Gerald A (Dec 2003). "In vitro protein complex formation with cytoskeleton-anchoring domain of occludin identified by limited proteolysis". J. Biol. Chem.278 (49): 49644–49651 issn = 0021–9258. PMID14512431. doi:10.1074/jbc.M302782200.
↑Wittchen, E S; Haskins J; Stevenson B R (Dec 1999). "Protein interactions at the tight junction. Actin has multiple binding partners, and ZO-1 forms independent complexes with ZO-2 and ZO-3". J. Biol. Chem.274 (49): 35179–35185. ISSN0021-9258. PMID10575001. doi:10.1074/jbc.274.49.35179.
↑Fanning, A S; Jameson B J; Jesaitis L A; Anderson J M (Nov 1998). "The tight junction protein ZO-1 establishes a link between the transmembrane protein occludin and the actin cytoskeleton". J. Biol. Chem.273 (45): 29745–29753 issn = 0021–9258. PMID9792688. doi:10.1074/jbc.273.45.29745.
Saitou M; Ando-Akatsuka Y; Itoh M; et al. (1997). "Mammalian occludin in epithelial cells: its expression and subcellular distribution". Eur. J. Cell Biol.73 (3): 222–31. PMID9243183.
Fanning AS, Jameson BJ, Jesaitis LA, Anderson JM (1998). "The tight junction protein ZO-1 establishes a link between the transmembrane protein occludin and the actin cytoskeleton". J. Biol. Chem.273 (45): 29745–29753. PMID9792688. doi:10.1074/jbc.273.45.29745.
Itoh M, Morita K, Tsukita S (1999). "Characterization of ZO-2 as a MAGUK family member associated with tight as well as adherens junctions with a binding affinity to occludin and alpha catenin". J. Biol. Chem.274 (9): 5981–5986. PMID10026224. doi:10.1074/jbc.274.9.5981.
Jiang WG; Martin TA; Matsumoto K; et al. (1999). "Hepatocyte growth factor/scatter factor decreases the expression of occludin and transendothelial resistance (TER) and increases paracellular permeability in human vascular endothelial cells". J. Cell. Physiol.181 (2): 319–329. PMID10497311. doi:10.1002/(SICI)1097-4652(199911)181:2<319::AID-JCP14>3.0.CO;2-S.
Wittchen ES, Haskins J, Stevenson BR (2000). "Protein interactions at the tight junction. Actin has multiple binding partners, and ZO-1 forms independent complexes with ZO-2 and ZO-3". J. Biol. Chem.274 (49): 35179–35185. PMID10575001. doi:10.1074/jbc.274.49.35179.
Kojima T; Sawada N; Chiba H; et al. (2000). "Induction of tight junctions in human connexin 32 (hCx32)-transfected mouse hepatocytes: connexin 32 interacts with occludin". Biochem. Biophys. Res. Commun.266 (1): 222–229. PMID10581193. doi:10.1006/bbrc.1999.1778.
Burns AR; Bowden RA; MacDonell SD; et al. (2000). "Analysis of tight junctions during neutrophil transendothelial migration". J. Cell. Sci.113 (1): 45–57. PMID10591624.
Singh U; Van Itallie CM; Mitic LL; et al. (2000). "CaCo-2 cells treated with Clostridium perfringens enterotoxin form multiple large complex species, one of which contains the tight junction protein occludin". J. Biol. Chem.275 (24): 18407–18417. PMID10749869. doi:10.1074/jbc.M001530200.
Marzioni D; Banita M; Felici A; et al. (2001). "Expression of ZO-1 and occludin in normal human placenta and in hydatidiform moles". Mol. Hum. Reprod.7 (3): 279–285. PMID11228248. doi:10.1093/molehr/7.3.279.
Andreeva AY; Krause E; Müller EC; et al. (2001). "Protein kinase C regulates the phosphorylation and cellular localization of occludin". J. Biol. Chem.276 (42): 38480–38486. PMID11502742. doi:10.1074/jbc.M104923200.
Papadopoulos MC; Saadoun S; Woodrow CJ; et al. (2001). "Occludin expression in microvessels of neoplastic and non-neoplastic human brain". Neuropathol. Appl. Neurobiol.27 (5): 384–395. PMID11679090. doi:10.1046/j.0305-1846.2001.00341.x.
Schmidt A, Utepbergenov DI, Krause G, Blasig IE (2001). "Use of surface plasmon resonance for real-time analysis of the interaction of ZO-1 and occludin". Biochem. Biophys. Res. Commun.288 (5): 1194–1199. PMID11700038. doi:10.1006/bbrc.2001.5914.
Traweger A; Fang D; Liu YC; et al. (2002). "The tight junction-specific protein occludin is a functional target of the E3 ubiquitin-protein ligase itch". J. Biol. Chem.277 (12): 10201–10208. PMID11782481. doi:10.1074/jbc.M111384200.