UniProt:P57739 CLDN2

chain
  • chain:1-230
checksum 52CA642D4A62B70D
comment
  • FUNCTION Forms paracellular channels: polymerizes in tight junction strands with cation- and water-selective channels through the strands, conveying epithelial permeability in a process known as paracellular tight junction permeability (PubMed:20460438, PubMed:36008380). In intestinal epithelium, allows for sodium and water fluxes from the peritoneal side to the lumen of the intestine to regulate nutrient absorption and clear enteric pathogens as part of mucosal immune response (By similarity). In kidney, allows passive sodium and calcium reabsorption across proximal tubules from the lumen back to the bloodstream (By similarity). In the hepatobiliary tract, allows paracellular water and cation fluxes in the hepatic perivenous areas and biliary epithelium to generate bile flow and maintain osmotic gradients (By similarity).CATALYTIC ACTIVITY Na(+)(in) = Na(+)(out)CATALYTIC ACTIVITY K(+)(in) = K(+)(out)CATALYTIC ACTIVITY Rb(+)(in) = Rb(+)(out)CATALYTIC ACTIVITY Li(+)(in) = Li(+)(out)CATALYTIC ACTIVITY Cs(+)(in) = Cs(+)(out)CATALYTIC ACTIVITY Ca(2+)(in) = Ca(2+)(out)CATALYTIC ACTIVITY methylamine(out) = methylamine(in)CATALYTIC ACTIVITY choline(out) = choline(in)CATALYTIC ACTIVITY H2O(in) = H2O(out)SUBUNIT Can form homo- and heteropolymers with other claudins to mediate paracellular barrier and channel functions of tight junctions in response to physiological stimuli. Homopolymers interact with CLDN3, but not CLDN1, homopolymers. Directly interacts with TJP1/ZO-1, TJP2/ZO-2 and TJP3/ZO-3.INTERACTION The disulfide bond is necessary for pore formation, but is not required for correct protein trafficking.DISEASE The disease may be caused by variants affecting the gene represented in this entry.SIMILARITY Belongs to the claudin family.
crossReference
databaseName UniProt
dbId 52234
description
  • recommendedName: fullName evidence="9"Claudin-2 alternativeName: SP82
displayName UniProt:P57739 CLDN2
geneName
  • CLDN2
  • PSEC0059
  • SP82
  • UNQ705/PRO1356
identifier P57739
isSequenceChanged false
keyword
  • 3D-structure
  • Cell junction
  • Cell membrane
  • Disease variant
  • Disulfide bond
  • Isopeptide bond
  • Membrane
  • Phosphoprotein
  • Proteomics identification
  • Reference proteome
  • Tight junction
  • Transmembrane
  • Transmembrane helix
  • Ubl conjugation
modified [InstanceEdit:9926675] Weiser, Joel, 2024-11-03
moleculeType Protein
name
  • CLDN2
otherIdentifier
  • 11724871_a_at
  • 11724872_a_at
  • 17105984
  • 223509_PM_at
  • 223509_at
  • 3986345
  • 3986347
  • 3986348
  • 3986349
  • 3986350
  • 3986351
  • 3986352
  • 3986353
  • 3986354
  • 3986355
  • 3986356
  • 3986357
  • 3986358
  • 3986371
  • 3986377
  • 48843_at
  • 52766_at
  • 8169210
  • 89771_at
  • 89774_at
  • 9075
  • A_14_P126553
  • A_23_P394947
  • A_33_P3249046
  • GE57008
  • GO:0002227
  • GO:0002376
  • GO:0005198
  • GO:0005215
  • GO:0005515
  • GO:0005654
  • GO:0005886
  • GO:0005911
  • GO:0005923
  • GO:0016020
  • GO:0016338
  • GO:0030054
  • GO:0034330
  • GO:0042802
  • GO:0070160
  • GO:0070161
  • GO:0070830
  • GO:0098542
  • GO:0098609
  • GO:0120188
  • GO:0160184
  • GO:0160187
  • GO:1903985
  • GO:1904729
  • HMNXSV003046119
  • ILMN_1795190
  • PH_hs_0030722
  • TC0X000521.hg
  • g10503979_3p_at
physicalEntity
referenceDatabase [ReferenceDatabase:2] UniProt
referenceGene
referenceTranscript
schemaClass ReferenceGeneProduct
secondaryIdentifier
  • CLD2_HUMAN
  • B2R6B9
sequenceLength 230
species [Species:48887] Homo sapiens
stId uniprot:P57739
url http://purl.uniprot.org/uniprot/P57739
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