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Protein

Keratin, type I cytoskeletal 18

Gene

Krt18

Organism
Mus musculus (Mouse)
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

When phosphorylated, plays a role in filament reorganization. Involved in the delivery of mutated CFTR to the plasma membrane. Involved in the uptake of thrombin-antithrombin complexes by hepatic cells (By similarity). Together with KRT8, is involved in interleukin-6 (IL-6)-mediated barrier protection.By similarity1 Publication

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sitei264Stutter1
Sitei324Stutter1

GO - Molecular functioni

GO - Biological processi

  • extrinsic apoptotic signaling pathway Source: MGI
  • Golgi to plasma membrane CFTR protein transport Source: MGI
  • hepatocyte apoptotic process Source: MGI
  • intermediate filament cytoskeleton organization Source: MGI
  • negative regulation of apoptotic process Source: MGI
  • tumor necrosis factor-mediated signaling pathway Source: MGI
Complete GO annotation...

Enzyme and pathway databases

ReactomeiR-MMU-6805567. Keratinization.
R-MMU-6809371. Formation of the cornified envelope.

Names & Taxonomyi

Protein namesi
Recommended name:
Keratin, type I cytoskeletal 18
Alternative name(s):
Cytokeratin endo B
Short name:
Keratin D
Cytokeratin-18
Short name:
CK-18
Keratin-18
Short name:
K18
Gene namesi
Name:Krt18
Synonyms:Kerd, Krt1-18
OrganismiMus musculus (Mouse)
Taxonomic identifieri10090 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaSciurognathiMuroideaMuridaeMurinaeMusMus
Proteomesi
  • UP000000589 Componenti: Chromosome 15

Organism-specific databases

MGIiMGI:96692. Krt18.

Subcellular locationi

GO - Cellular componenti

  • cell-cell adherens junction Source: MGI
  • cell periphery Source: MGI
  • centriolar satellite Source: MGI
  • cytoplasm Source: MGI
  • extracellular exosome Source: MGI
  • intermediate filament Source: MGI
  • keratin filament Source: MGI
  • microtubule organizing center Source: MGI
  • nuclear matrix Source: UniProtKB-SubCell
  • nucleolus Source: UniProtKB-SubCell
Complete GO annotation...

Keywords - Cellular componenti

Cytoplasm, Intermediate filament, Keratin, Nucleus

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Initiator methionineiRemovedBy similarity
ChainiPRO_00000636672 – 423Keratin, type I cytoskeletal 18Add BLAST422

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei2N-acetylserineBy similarity1
Modified residuei7PhosphoserineBy similarity1
Modified residuei11PhosphoserineBy similarity1
Modified residuei16PhosphoserineBy similarity1
Modified residuei19PhosphoserineBy similarity1
Modified residuei31Phosphoserine; alternateCombined sources1
Glycosylationi31O-linked (GlcNAc); alternateBy similarity1
Modified residuei32Phosphoserine; alternateCombined sources1
Glycosylationi32O-linked (GlcNAc); alternateBy similarity1
Modified residuei35PhosphoserineCombined sources1
Modified residuei37PhosphotyrosineCombined sources1
Modified residuei43PhosphoserineCombined sources1
Modified residuei46Omega-N-methylarginineBy similarity1
Modified residuei50Phosphoserine; alternateBy similarity1
Glycosylationi50O-linked (GlcNAc); alternateBy similarity1
Modified residuei52Phosphoserine; by MAPKAPK2 and MAPKAPK31 Publication1
Modified residuei57PhosphoserineCombined sources1
Modified residuei60PhosphoserineBy similarity1
Modified residuei85PhosphoserineBy similarity1
Modified residuei92PhosphoserineBy similarity1
Modified residuei124N6-acetyllysineBy similarity1
Modified residuei137PhosphoserineCombined sources1
Modified residuei170PhosphoserineBy similarity1
Modified residuei295PhosphothreonineBy similarity1
Modified residuei316PhosphoserineCombined sources1
Modified residuei384PhosphoserineCombined sources1
Modified residuei391PhosphoserineCombined sources1
Modified residuei392PhosphoserineBy similarity1
Modified residuei394PhosphoserineBy similarity1
Modified residuei397PhosphothreonineBy similarity1

Post-translational modificationi

Phosphorylation increases by IL-6.2 Publications
Proteolytically cleaved by caspases during epithelial cell apoptosis. Cleavage occurs at Asp-231 by either caspase-3, caspas-6 or caspase-7.1 Publication
O-GlcNAcylation increases solubility, and decreases stability by inducing proteasomal degradation.By similarity

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sitei231 – 232Cleavage; by caspase-3, caspase-6 or caspase-72

Keywords - PTMi

Acetylation, Glycoprotein, Methylation, Phosphoprotein

Proteomic databases

EPDiP05784.
PaxDbiP05784.
PeptideAtlasiP05784.
PRIDEiP05784.

2D gel databases

SWISS-2DPAGEP05784.

PTM databases

iPTMnetiP05784.
PhosphoSitePlusiP05784.

Expressioni

Tissue specificityi

Expressed in endoderm, intestinal epithelial cells and in most extraembryonic tissues.4 Publications

Developmental stagei

During embryogenesis, expressed in a complex spatial and temporal pattern in various embryonic epithelia. In 7.5 and 13.5 day old embryo, expressed in most endodermal epithelia, ectodermal and nascent mesodermal tissues. When the neural plate forms, expression begins in the cells of skin ectoderm, head process/notochord, periderm, whisker buds, choroid plexus and the epithelia of auditory duct and inner ear. High expression in the lining endodermal cells when the foregut and hindgut invaginations form. Expression in all three layers of the urothelium starts at day 15 in the embryo and is not visible after day 18. By day 11 and 12, the entire embryonic palatal epithelium shows expression as well as the nasal passages and the roof of the mouth; which disappears progresively from day 13 to 15.3 Publications

Inductioni

By retinoic acid and IL-6.2 Publications

Gene expression databases

BgeeiENSMUSG00000023043.
CleanExiMM_KRT18.
GenevisibleiP05784. MM.

Interactioni

Subunit structurei

Heterotetramer of two type I and two type II keratins. KRT18 associates with KRT8. Interacts with PNN, HCV core protein and mutated CFTR. Interacts with YWHAE, YWHAH and YWHAZ only when phosphorylated. Interacts with the thrombin-antithrombin complex. Interacts with DNAJB6, TCHP and TRADD (By similarity). Interacts with FAM83H (By similarity). Interacts with EPPK1 (PubMed:25617501).By similarity1 Publication

GO - Molecular functioni

Protein-protein interaction databases

BioGridi201023. 1 interactor.
IntActiP05784. 5 interactors.
MINTiMINT-1866927.
STRINGi10090.ENSMUSP00000023803.

Structurei

3D structure databases

ProteinModelPortaliP05784.
SMRiP05784.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni2 – 71HeadAdd BLAST70
Regioni62 – 366Necessary for interaction with PNNBy similarityAdd BLAST305
Regioni69 – 121Interaction with TRADDBy similarityAdd BLAST53
Regioni72 – 380RodAdd BLAST309
Regioni72 – 107Coil 1AAdd BLAST36
Regioni108 – 125Linker 1Add BLAST18
Regioni126 – 217Coil 1BAdd BLAST92
Regioni218 – 241Linker 12Add BLAST24
Regioni236 – 384Interaction with DNAJB6By similarityAdd BLAST149
Regioni242 – 380Coil 2Add BLAST139
Regioni381 – 423TailAdd BLAST43

Sequence similaritiesi

Belongs to the intermediate filament family.Curated

Keywords - Domaini

Coiled coil

Phylogenomic databases

eggNOGiENOG410IEYR. Eukaryota.
ENOG4111DJ8. LUCA.
GeneTreeiENSGT00760000119046.
HOGENOMiHOG000230975.
HOVERGENiHBG013015.
InParanoidiP05784.
KOiK07604.
OMAiRAKYEKM.
OrthoDBiEOG091G0A3U.
PhylomeDBiP05784.
TreeFamiTF332742.

Family and domain databases

InterProiIPR001664. IF.
IPR018039. Intermediate_filament_CS.
IPR027695. Keratin-18.
IPR002957. Keratin_I.
[Graphical view]
PANTHERiPTHR23239. PTHR23239. 1 hit.
PTHR23239:SF35. PTHR23239:SF35. 1 hit.
PfamiPF00038. Filament. 1 hit.
[Graphical view]
PRINTSiPR01248. TYPE1KERATIN.
SMARTiSM01391. Filament. 1 hit.
[Graphical view]
PROSITEiPS00226. IF. 1 hit.
[Graphical view]

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

P05784-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MSFTTRSTTF STNYRSLGSV RTPSQRVRPA SSAASVYAGA GGSGSRISVS
60 70 80 90 100
RSVWGGSVGS AGLAGMGGIQ TEKETMQDLN DRLASYLDKV KSLETENRRL
110 120 130 140 150
ESKIREHLEK KGPQGVRDWG HYFKIIEDLR AQIFANSVDN ARIVLQIDNA
160 170 180 190 200
RLAADDFRVK YETELAMRQS VESDIHGLRK VVDDTNITRL QLETEIEALK
210 220 230 240 250
EELLFMKKNH EEEVQGLEAQ IASSGLTVEV DAPKSQDLSK IMADIRAQYE
260 270 280 290 300
ALAQKNREEL DKYWSQQIEE STTVVTTKSA EIRDAETTLT ELRRTLQTLE
310 320 330 340 350
IDLDSMKNQN INLENSLGDV EARYKAQMEQ LNGVLLHLES ELAQTRAEGQ
360 370 380 390 400
RQAQEYEALL NIKVKLEAEI ATYRRLLEDG EDFSLNDALD SSNSMQTVQK
410 420
TTTRKIVDGR VVSETNDTRV LRH
Length:423
Mass (Da):47,538
Last modified:May 29, 2007 - v5
Checksum:iA67ACD6814A02118
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti134F → L in AAA39390 (PubMed:2416755).Curated1
Sequence conflicti134F → L in AAA39373 (Ref. 2) Curated1
Sequence conflicti214V → A in BAE26424 (PubMed:16141072).Curated1
Sequence conflicti214V → A in BAE39378 (PubMed:16141072).Curated1
Sequence conflicti244D → N in AAA39373 (Ref. 2) Curated1
Sequence conflicti253A → G in AAA39373 (Ref. 2) Curated1
Sequence conflicti300E → G in BAE39725 (PubMed:16141072).Curated1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M11686 mRNA. Translation: AAA39390.1.
M36376 mRNA. Translation: AAA39373.1.
M22832 Genomic DNA. Translation: AAA37552.1.
AK145413 mRNA. Translation: BAE26424.1.
AK167072 mRNA. Translation: BAE39232.1.
AK167265 mRNA. Translation: BAE39378.1.
AK167432 mRNA. Translation: BAE39519.1.
AK167469 mRNA. Translation: BAE39553.1.
AK167676 mRNA. Translation: BAE39725.1.
BC089022 mRNA. Translation: AAH89022.1.
Y00217 Genomic DNA. Translation: CAA68365.1.
CCDSiCCDS27869.1.
PIRiI59463.
RefSeqiNP_034794.2. NM_010664.2.
UniGeneiMm.22479.

Genome annotation databases

EnsembliENSMUST00000023803; ENSMUSP00000023803; ENSMUSG00000023043.
GeneIDi16668.
KEGGimmu:16668.
UCSCiuc007xuj.2. mouse.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M11686 mRNA. Translation: AAA39390.1.
M36376 mRNA. Translation: AAA39373.1.
M22832 Genomic DNA. Translation: AAA37552.1.
AK145413 mRNA. Translation: BAE26424.1.
AK167072 mRNA. Translation: BAE39232.1.
AK167265 mRNA. Translation: BAE39378.1.
AK167432 mRNA. Translation: BAE39519.1.
AK167469 mRNA. Translation: BAE39553.1.
AK167676 mRNA. Translation: BAE39725.1.
BC089022 mRNA. Translation: AAH89022.1.
Y00217 Genomic DNA. Translation: CAA68365.1.
CCDSiCCDS27869.1.
PIRiI59463.
RefSeqiNP_034794.2. NM_010664.2.
UniGeneiMm.22479.

3D structure databases

ProteinModelPortaliP05784.
SMRiP05784.
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

BioGridi201023. 1 interactor.
IntActiP05784. 5 interactors.
MINTiMINT-1866927.
STRINGi10090.ENSMUSP00000023803.

PTM databases

iPTMnetiP05784.
PhosphoSitePlusiP05784.

2D gel databases

SWISS-2DPAGEP05784.

Proteomic databases

EPDiP05784.
PaxDbiP05784.
PeptideAtlasiP05784.
PRIDEiP05784.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENSMUST00000023803; ENSMUSP00000023803; ENSMUSG00000023043.
GeneIDi16668.
KEGGimmu:16668.
UCSCiuc007xuj.2. mouse.

Organism-specific databases

CTDi3875.
MGIiMGI:96692. Krt18.

Phylogenomic databases

eggNOGiENOG410IEYR. Eukaryota.
ENOG4111DJ8. LUCA.
GeneTreeiENSGT00760000119046.
HOGENOMiHOG000230975.
HOVERGENiHBG013015.
InParanoidiP05784.
KOiK07604.
OMAiRAKYEKM.
OrthoDBiEOG091G0A3U.
PhylomeDBiP05784.
TreeFamiTF332742.

Enzyme and pathway databases

ReactomeiR-MMU-6805567. Keratinization.
R-MMU-6809371. Formation of the cornified envelope.

Miscellaneous databases

ChiTaRSiKrt18. mouse.
PROiP05784.
SOURCEiSearch...

Gene expression databases

BgeeiENSMUSG00000023043.
CleanExiMM_KRT18.
GenevisibleiP05784. MM.

Family and domain databases

InterProiIPR001664. IF.
IPR018039. Intermediate_filament_CS.
IPR027695. Keratin-18.
IPR002957. Keratin_I.
[Graphical view]
PANTHERiPTHR23239. PTHR23239. 1 hit.
PTHR23239:SF35. PTHR23239:SF35. 1 hit.
PfamiPF00038. Filament. 1 hit.
[Graphical view]
PRINTSiPR01248. TYPE1KERATIN.
SMARTiSM01391. Filament. 1 hit.
[Graphical view]
PROSITEiPS00226. IF. 1 hit.
[Graphical view]
ProtoNetiSearch...

Entry informationi

Entry nameiK1C18_MOUSE
AccessioniPrimary (citable) accession number: P05784
Secondary accession number(s): Q3TIX1
, Q3TJH6, Q3TJW7, Q61766
Entry historyi
Integrated into UniProtKB/Swiss-Prot: November 1, 1988
Last sequence update: May 29, 2007
Last modified: November 30, 2016
This is version 150 of the entry and version 5 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

Miscellaneousi

Miscellaneous

There are two types of cytoskeletal and microfibrillar keratin: I (acidic; 40-55 kDa) and II (neutral to basic; 56-70 kDa).

Keywords - Technical termi

Complete proteome, Reference proteome

Documents

  1. MGD cross-references
    Mouse Genome Database (MGD) cross-references in UniProtKB/Swiss-Prot
  2. SIMILARITY comments
    Index of protein domains and families

Similar proteinsi

Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into one UniRef entry.
90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.