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Symbol OCLN contributors: npt/mct/pgu - updated : 03-06-2014
HGNC name occludin
HGNC id 8104
Corresponding disease
BCPMG band-like calcification with simplified gyration and polymicrogyria
Location 5q13.2      Physical location : 68.788.118 - 68.850.130
Synonym name tight junction protein occludin TM4 minus
TYPE functioning gene
STRUCTURE 65.81 kb     9 Exon(s)
10 Kb 5' upstream gene genomic sequence study
regulatory sequence Promoter
text structure an additional promoter and transcription start giving rise to an alternative exon 1
MAPPING cloned Y linked N status provisional
Physical map
EEF1B3 5q12-q14 eukaryotic translation elongation factor 1 beta 3 PIK3R1 5q12-q13 phosphoinositide-3-kinase, regulatory subunit, polypeptide 1 (p85 alpha) SLC30A5 5q12.1 solute carrier family 30 (zinc transporter), member 5 CCNB1 5q11-q12 cyclin B1 CENPH 5p15.2 centromere protein H MRPS36 5q13.3 mitochondrial ribosomal protein S36 CDK7 2p15-pcen cyclin-dependent kinase 7 (MO15 homolog, Xenopus laevis, cdk-activating kinase) KENAE 5q13.1 Kenae LOC285653 5q13.1 similar to chromosome 7 open reading frame 17 protein; 16.7kD protein TAF9 5q12 TAF9 RNA polymerase II, TATA box binding protein (TBP)-associated factor, 32kDa RAD17 5q12-q13.1 RAD17 homolog (S. pombe) FLJ30532 5q13.1 hypothetical protein FLJ30532 OCLN 5q13.1 occludin GTF2H2 5q13.1 general transcription factor IIH, polypeptide 2, 44kDa BIRC1 5q13.1 baculoviral IAP repeat-containing 1 SMN1 5q13.1 survival of motor neuron 1, telomeric LOC391791 5 similar to cadherin 12, type 2 preproprotein; Br-cadherin; cadherin-12; N-cadherin 2; brain-cadherin; neuronal cadherin 2; cadherin, neural type, 2 SMA3 5q13 SMA3 LOC389294 5 similar to bA110H4.2 (similar to membrane protein) LOC391792 5 similar to SMA3 protein LOC340089 5q13.2 similar to bA110H4.2 (similar to membrane protein) LOC391793 5 similar to cadherin 12, type 2 preproprotein; Br-cadherin; cadherin-12; N-cadherin 2; brain-cadherin; neuronal cadherin 2; cadherin, neural type, 2 SERF1A 5q13.1 small EDRK-rich factor 1A (telomeric) SMN2 5q13.1 survival of motor neuron 2, centromeric LOC389295 5 LOC389295 LOC389296 5 similar to Beta-glucuronidase precursor (Beta-G1) LOC389297 5 similar to bA110H4.2 (similar to membrane protein) LOC389298 5 similar to bA110H4.2 (similar to membrane protein) LOC389299 5 similar to Beta-glucuronidase precursor (Beta-G1) LOC391794 5 similar to cadherin 12, type 2 preproprotein; Br-cadherin; cadherin-12; N-cadherin 2; brain-cadherin; neuronal cadherin 2; cadherin, neural type, 2
TRANSCRIPTS type messenger
  • remarkable natural splicing diversity of OCLN might contribute to HCV tissue tropism and possibly modify the outcome of HCV infection in humans (PMID: 20463075)
  • identificationnb exonstypebpproduct
    ProteinkDaAAspecific expressionYearPubmed
    9 - 6451 65 522 - 2010 20463075
    9 - 6221 - 522 - 2010 20463075
    7 - 5404 - 271 - 2010 20463075
    Type widely
       expressed in (based on citations)
    SystemOrgan level 1Organ level 2Organ level 3Organ level 4LevelPubmedSpeciesStageRna symbol
    Digestiveesophagus   highly
    Nervousbrain   highly
    Reproductivemale systemtestis  highly
    Respiratoryrespiratory tracttrachea  highly
    Urinarykidney   highly
    SystemCellPubmedSpeciesStageRna symbol
     epithelial cell
    cell lineage
    cell lines
    at STAGE
    Text in the developing human brain, occludin is expressed early in neuroepithelium, but expression is lost during the transition from epithelia to neuronal cell types
  • N-terminal extracellular domains mediate homotypic adhesion
  • the four membrane spanning domains and the extracellular and intracellular loops contain sequences that constitute a MARVEL domain hypothesized to confer trafficking properties
  • C-terminal cytoplasmic domain controls protein targeting and endocytosis, is heavily phosphorylated, and S408 phosphorylation regulates tight junction protein interactions and barrier function , with the distal C terminus(AAs 413-452, forming a coiled-coil region necessary for TJP1 binding , coiled-coil occludin/ELL domain (OCEL)
  • an N and C terminus within the cytoplasm
  • ELL/occludin family
  • CATEGORY adhesion
    SUBCELLULAR LOCALIZATION     plasma membrane,junction,tight
  • protein constituent of integral membrane at tight junctions of epithelial cells
  • localizes with centrosomes during interphase and occludin Ser-490 phosphorylation at centrosomes increases with mitotic entry
  • basic FUNCTION
  • accessory protein in tight junction strands formation, playing a role in both the formation of the paracellular barrier and in cell signaling
  • involved in the regulation of paracellular permeability as well as in the targeting of the protein to the tight junction
  • colocalised in the salivary excretory ducts with the tight junction proteins TJP1 and CLDN16 suggesting a potential role in paracellular calcium and magnesium transport
  • MARVELD3, OCLN, and MARVELD2 are best considered as a group with both redundant and unique contributions to epithelial function and tight junction regulation
  • integral tight junction protein, that is one of the key factors for HCV entry into cells
  • roles in epithelial barrier formation and maintenance
  • contributes to centrosomal separation and mitotic entry through Ser-490 phosphorylation
  • role for occludin in centrosome separation providing compelling evidence for a role of occludin in the regulation of mitotic entry
  • is involved in adhesion, apoptosis, differentiation and Ca2+-homeostasis of human keratinocytes (pmid: 23390516)
    a component
  • MARVELD3, OCLN, and MARVELD2 define the tight junction-associated MARVEL protein family
  • ABCB1 and an integrated component of the occludin/zonula occludens 1 (TJP1) adhesion complex at the BTB, structurally interacted with PTK2, creating the OCLN/TJP1/PTK2/ABCB1 regulatory complex
    small molecule
  • C terminus can also bind to the scaffolding proteins TJP1, TJP2, TJP3, cingulin, the membrane trafficking protein VAP33, and the cytoskeletal protein F-actin
  • OCLN supports tricellular localization of MARVELD2 by excluding MARVELD2 from bTJs (bicellular tight junctions)
  • interaction with PTPRJ and TJP1 specific (occludin and TJP1 were dephosphorylated by PTPRJ but not the other phosphatases)
  • target of VEGFA action in the blood-brain barrier
  • NKX2-1 transactivated the expression of the epithelial tight junction molecules occludin (OCLN) and CLDN1
  • CELF1 represses OCLN translation by increasing occludin mRNA recruitment to P-bodies
  • ELAVL1 promotes OCLN translation by blocking occludin mRNA translocation to P-bodies via the displacement of ELAVL1
  • OCLN, MARVELD3 and MARVELD2 exhibited homophilic cis-interactions, along one plasma membrane (claudins regulate the interactions between OCLN, MARVELD2 and MARVELD3, which, inversely, modulate claudin oligomerization)
  • OCEL-domain interactions are required for maintenance and regulation of the tight junction barrier to macromolecular flux
  • KLF4 regulates blood-tumor barrier permeability via TJP1, OCLN and CLDN5
  • cell & other
    Other phosphorylation of OCLN Ser-490 contributes to centrosome function in cell division derives from mutational analysis preventing Ser-490 phosphorylation
    corresponding disease(s) BCPMG
    Other morbid association(s)
    TypeGene ModificationChromosome rearrangementProtein expressionProtein Function
    constitutional     --over  
    in Alzheimer disease and vascular dementia
    tumoral     --other  
    aberrantly methylated promoter associated CpG islands in acute lymphocytic leukemia
    constitutional       loss of function
    OCLN deficiency with BACE1 elevation in cerebral amyloid angiopathy (CAA)
    Variant & Polymorphism
    Candidate gene
    Therapy target