UniProt:P05783 KRT18

chain
  • initiator methionine:1
  • chain:2-430
checksum 1E5604C6BCC7A17A
comment
  • FUNCTION Required for the formation of KRT8/KRT18 filaments that are involved in ARHGEF40-mediated actin stress fiber formation and tensional force-induced stress fiber formation and reinforcement (PubMed:26823019). Also acts downstream of ROCK kinase activation as part of a positive feedback mechanism in response to cellular mechanical stress loading (PubMed:26823019). Organization and orientation of KRT18 filaments are responsible for the properly elongated morphology of epithelial tubules (By similarity). Involved in the uptake of thrombin-antithrombin complexes by hepatic cells (By similarity). When phosphorylated, plays a role in filament reorganization. Involved in the delivery of mutated CFTR to the plasma membrane. Together with KRT8, is involved in interleukin-6 (IL-6)-mediated barrier protection.SUBUNIT Heterotetramer of two type I and two type II keratins. KRT18 associates with KRT8 (PubMed:10852826, PubMed:24940650, PubMed:26823019). Interacts with PLEC isoform 1C, when in a heterodimer with KRT8 (PubMed:24940650). Interacts with the thrombin-antithrombin complex (By similarity). Interacts with PNN and mutated CFTR. Interacts with YWHAE, YWHAH and YWHAZ only when phosphorylated. Interacts with DNAJB6, TCHP and TRADD. Interacts with FAM83H (PubMed:23902688). Interacts with EPPK1 (By similarity). Interacts with PKP1 and PKP2 (PubMed:10852826). KRT8/KRT18 heterodimers interact with ARHGEF40 (via N-terminal, central and C-terminal domains) (PubMed:26823019). The interaction facilitates actin stress fiber formation, force-induced stress fiber reinforcement and organization of KRT8/KRT18 networks (PubMed:30929300).SUBUNIT (Microbial infection) Interacts with hepatitis C virus/HCV core protein.INTERACTION Expressed in colon, placenta, liver and very weakly in exocervix. Increased expression observed in lymph nodes of breast carcinoma.INDUCTION By IL6/interleukin-6.PTM Phosphorylation at Ser-34 increases during mitosis. Hyperphosphorylated at Ser-53 in diseased cirrhosis liver. Phosphorylation increases by IL-6.PTM Proteolytically cleaved by caspases during epithelial cell apoptosis. Cleavage occurs at Asp-238 by either caspase-3, caspase-6 or caspase-7.PTM O-GlcNAcylation increases solubility, and decreases stability by inducing proteasomal degradation.DISEASE The disease is caused by variants affecting the gene represented in this entry.MISCELLANEOUS There are two types of cytoskeletal and microfibrillar keratin: I (acidic; 40-55 kDa) and II (neutral to basic; 56-70 kDa).SIMILARITY Belongs to the intermediate filament family.
crossReference
databaseName UniProt
dbId 57711
description
  • recommendedName: fullName evidence="34"Keratin, type I cytoskeletal 18 alternativeName: Cell proliferation-inducing gene 46 protein alternativeName: fullName evidence="33"Cytokeratin-18 shortName evidence="33"CK-18 alternativeName: fullName evidence="35"Keratin-18 shortName: K18
displayName UniProt:P05783 KRT18
geneName
  • KRT18
  • CYK18
  • PIG46
identifier P05783
isSequenceChanged false
keyword
  • Acetylation
  • Cell cycle
  • Coiled coil
  • Cytoplasm
  • Direct protein sequencing
  • Disease variant
  • Glycoprotein
  • Host-virus interaction
  • Intermediate filament
  • Isopeptide bond
  • Keratin
  • Methylation
  • Nucleus
  • Phosphoprotein
  • Proteomics identification
  • Reference proteome
  • Ubl conjugation
modified [InstanceEdit:9983091] Weiser, Joel, 2026-02-20
moleculeType Protein
name
  • KRT18
otherIdentifier
  • 11754941_x_at
  • 11757905_x_at
  • 16751554
  • 201596_3p_x_at
  • 201596_PM_x_at
  • 201596_x_at
  • 2387518
  • 2428038
  • 2486000
  • 2547288
  • 2590563
  • 2591755
  • 2595700
  • 2595708
  • 2663331
  • 2663335
  • 2698437
  • 2807570
  • 2823519
  • 3095758
  • 3211132
  • 3360711
  • 3360716
  • 3415581
  • 3415582
  • 3415583
  • 3415584
  • 3415585
  • 3415586
  • 3415587
  • 3415588
  • 3415589
  • 3415590
  • 3415591
  • 3415592
  • 3415595
  • 3415596
  • 3415597
  • 3415598
  • 3415599
  • 3415600
  • 3415601
  • 3415602
  • 3415603
  • 3415604
  • 3415605
  • 3415606
  • 3469239
  • 35766_at
  • 3668093
  • 3750580
  • 3875
  • 3900972
  • 3953578
  • 3983628
  • 3983630
  • 3983638
  • 3983640
  • 4028791
  • 4028795
  • 4028803
  • 73111_s_at
  • 7955637
  • 7969574
  • 8154725
  • 88041_at
  • 88043_g_at
  • A_14_P129839
  • A_14_P136583
  • A_14_P136956
  • A_23_P99320
  • GE79057
  • GO:0003723
  • GO:0005198
  • GO:0005515
  • GO:0005634
  • GO:0005730
  • GO:0005737
  • GO:0005815
  • GO:0005829
  • GO:0005856
  • GO:0005882
  • GO:0005912
  • GO:0007010
  • GO:0009653
  • GO:0016192
  • GO:0016363
  • GO:0033209
  • GO:0034451
  • GO:0043001
  • GO:0043066
  • GO:0045095
  • GO:0045104
  • GO:0048471
  • GO:0070062
  • GO:0071944
  • GO:0072659
  • GO:0097110
  • GO:0097191
  • GO:0097284
  • GO:0098609
  • GO:0098641
  • HMNXSV003043586
  • HMNXSV003047737
  • ILMN_1694778
  • ILMN_1730848
  • ILMN_1803408
  • PH_hs_0037365
  • TC12000424.hg
  • X12876_s_at
  • g4557887_3p_at
  • g4557887_3p_x_at
physicalEntity
referenceDatabase [ReferenceDatabase:2] UniProt
referenceGene
referenceTranscript
schemaClass ReferenceGeneProduct
secondaryIdentifier
  • K1C18_HUMAN
  • Q53G38
  • Q5U0N8
  • Q9BW26
sequenceLength 430
species [Species:48887] Homo sapiens
stId uniprot:P05783
url http://purl.uniprot.org/uniprot/P05783
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