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Protein

Keratin, type II cytoskeletal 4

Gene

KRT4

Organism
Homo sapiens (Human)
Status
Reviewed-Annotation score: -Experimental evidence at protein leveli

Functioni

Miscellaneous

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

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sitei402Stutter1

GO - Molecular functioni

GO - Biological processi

Enzyme and pathway databases

ReactomeiR-HSA-6805567 Keratinization
R-HSA-6809371 Formation of the cornified envelope
SIGNORiP19013

Names & Taxonomyi

Protein namesi
Recommended name:
Keratin, type II cytoskeletal 4
Alternative name(s):
Cytokeratin-4
Short name:
CK-4
Keratin-4
Short name:
K4
Type-II keratin Kb4
Gene namesi
Name:KRT4
Synonyms:CYK4
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 12

Organism-specific databases

EuPathDBiHostDB:ENSG00000170477.12
HGNCiHGNC:6441 KRT4
MIMi123940 gene
neXtProtiNX_P19013

Subcellular locationi

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionGraphics by Christian Stolte; Source: COMPARTMENTS

Keywords - Cellular componenti

Intermediate filament, Keratin

Pathology & Biotechi

Involvement in diseasei

White sponge nevus 1 (WSN1)2 Publications
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionA rare disorder characterized by the presence of soft, white, and spongy plaques in the oral mucosa. The characteristic histopathologic features are epithelial thickening, parakeratosis, and vacuolization of the suprabasal layer of oral epithelial keratinocytes. Less frequently the mucous membranes of the nose, esophagus, genitalia and rectum are involved.
See also OMIM:193900
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_012845153E → EQ in WSN1. 1 Publication1
Natural variantiVAR_016038449E → K in WSN1. 1 Publication1

Keywords - Diseasei

Disease mutation

Organism-specific databases

DisGeNETi3851
MalaCardsiKRT4
MIMi193900 phenotype
Orphaneti171723 White sponge nevus
PharmGKBiPA30229

Polymorphism and mutation databases

DMDMi82654947

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00000637221 – 534Keratin, type II cytoskeletal 4Add BLAST534

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei13Omega-N-methylarginineBy similarity1

Keywords - PTMi

Methylation

Proteomic databases

PaxDbiP19013
PeptideAtlasiP19013
PRIDEiP19013
ProteomicsDBi53621

PTM databases

iPTMnetiP19013
PhosphoSitePlusiP19013
SwissPalmiP19013

Expressioni

Tissue specificityi

Detected in the suprabasal layer of the stratified epithelium of the esophagus, exocervix, vagina, mouth and lingual mucosa, and in cells and cell clusters in the mucosa and serous gland ducts of the esophageal submucosa (at protein level). Expressed widely in the exocervix and esophageal epithelium, with lowest levels detected in the basal cell layer.1 Publication

Gene expression databases

BgeeiENSG00000170477 Expressed in 114 organ(s), highest expression level in tongue squamous epithelium
CleanExiHS_KRT4
ExpressionAtlasiP19013 baseline and differential
GenevisibleiP19013 HS

Organism-specific databases

HPAiCAB002154
HPA034881

Interactioni

Subunit structurei

Heterotetramer of two type I and two type II keratins. Keratin-4 is generally associated with keratin-13.

Binary interactionsi

Protein-protein interaction databases

IntActiP19013, 38 interactors
MINTiP19013
STRINGi9606.ENSP00000448220

Structurei

3D structure databases

ProteinModelPortaliP19013
SMRiP19013
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini151 – 464IF rodPROSITE-ProRule annotationAdd BLAST314

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni1 – 150HeadAdd BLAST150
Regioni151 – 186Coil 1AAdd BLAST36
Regioni187 – 205Linker 1Add BLAST19
Regioni206 – 298Coil 1BAdd BLAST93
Regioni299 – 321Linker 12Add BLAST23
Regioni322 – 461Coil 2Add BLAST140
Regioni462 – 534TailAdd BLAST73

Compositional bias

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Compositional biasi10 – 122Gly-richAdd BLAST113
Compositional biasi470 – 526Ser-richAdd BLAST57

Sequence similaritiesi

Belongs to the intermediate filament family.PROSITE-ProRule annotation

Keywords - Domaini

Coiled coil

Phylogenomic databases

eggNOGiENOG410IGG3 Eukaryota
ENOG410ZE7B LUCA
HOGENOMiHOG000230976
HOVERGENiHBG013015
InParanoidiP19013
OrthoDBiEOG091G09KR
PhylomeDBiP19013
TreeFamiTF317854

Family and domain databases

InterProiView protein in InterPro
IPR001664 IF
IPR018039 IF_conserved
IPR039008 IF_rod_dom
IPR032444 Keratin_2_head
IPR003054 Keratin_II
PANTHERiPTHR23239 PTHR23239, 1 hit
PfamiView protein in Pfam
PF00038 Filament, 1 hit
PF16208 Keratin_2_head, 1 hit
PRINTSiPR01276 TYPE2KERATIN
SMARTiView protein in SMART
SM01391 Filament, 1 hit
PROSITEiView protein in PROSITE
PS00226 IF_ROD_1, 1 hit
PS51842 IF_ROD_2, 1 hit

Sequence (1+)i

Sequence statusi: Complete.

This entry has 1 described isoform and 2 potential isoforms that are computationally mapped.iShow all

P19013-1 [UniParc]FASTAAdd to basket
« Hide
        10         20         30         40         50
MIARQQCVRG GPRGFSCGSA IVGGGKRGAF SSVSMSGGAG RCSSGGFGSR
60 70 80 90 100
SLYNLRGNKS ISMSVAGSRQ GACFGGAGGF GTGGFGAGGF GAGFGTGGFG
110 120 130 140 150
GGFGGSFSGK GGPGFPVCPA GGIQEVTINQ SLLTPLHVEI DPEIQKVRTE
160 170 180 190 200
EREQIKLLNN KFASFIDKVQ FLEQQNKVLE TKWNLLQQQT TTTSSKNLEP
210 220 230 240 250
LFETYLSVLR KQLDTLGNDK GRLQSELKTM QDSVEDFKTK YEEEINKRTA
260 270 280 290 300
AENDFVVLKK DVDAAYLNKV ELEAKVDSLN DEINFLKVLY DAELSQMQTH
310 320 330 340 350
VSDTSVVLSM DNNRNLDLDS IIAEVRAQYE EIAQRSKAEA EALYQTKVQQ
360 370 380 390 400
LQISVDQHGD NLKNTKSEIA ELNRMIQRLR AEIENIKKQC QTLQVSVADA
410 420 430 440 450
EQRGENALKD AHSKRVELEA ALQQAKEELA RMLREYQELM SVKLALDIEI
460 470 480 490 500
ATYRKLLEGE EYRMSGECQS AVSISVVSGS TSTGGISGGL GSGSGFGLSS
510 520 530
GFGSGSGSGF GFGGSVSGSS SSKIISTTTL NKRR
Length:534
Mass (Da):57,285
Last modified:November 22, 2005 - v4
Checksum:i3795B7C93092F97E
GO

Computationally mapped potential isoform sequencesi

There are 2 potential isoforms mapped to this entry.BLASTAlignShow allAdd to basket
EntryEntry nameProtein names
Gene namesLengthAnnotation
F8VX05F8VX05_HUMAN
Keratin, type II cytoskeletal 4
KRT4
78Annotation score:
F8VZR6F8VZR6_HUMAN
Keratin, type II cytoskeletal 4
KRT4
86Annotation score:

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti118C → L in CAA47914 (PubMed:7684424).Curated1
Sequence conflicti127 – 128TI → SL in CAA30534 (PubMed:2452170).Curated2
Sequence conflicti236D → Y in AAH03630 (PubMed:15489334).Curated1

Polymorphismi

Three alleles of K4 are known: K4A2 (shown here), K4A1 and K4B.

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_00386972A → V in allele K4A1. 1 Publication1
Natural variantiVAR_00387083 – 96Missing in allele K4B. 2 PublicationsAdd BLAST14
Natural variantiVAR_012845153E → EQ in WSN1. 1 Publication1
Natural variantiVAR_016038449E → K in WSN1. 1 Publication1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AY043326 Genomic DNA Translation: AAL14196.1
AC107016 Genomic DNA No translation available.
BC003630 mRNA Translation: AAH03630.2
BC042174 mRNA Translation: AAH42174.1
X67683 mRNA Translation: CAA47914.1
X07695 mRNA Translation: CAA30534.1
X61028 Genomic DNA Translation: CAA43362.1
PIRiI37942
UniGeneiHs.654610
Hs.731814

Genome annotation databases

EnsembliENST00000293774; ENSP00000293774; ENSG00000170477
ENST00000551956; ENSP00000448220; ENSG00000170477
UCSCiuc031qhk.2 human

Keywords - Coding sequence diversityi

Polymorphism

Similar proteinsi

Cross-referencesi

Web resourcesi

Human Intermediate Filament Mutation Database

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AY043326 Genomic DNA Translation: AAL14196.1
AC107016 Genomic DNA No translation available.
BC003630 mRNA Translation: AAH03630.2
BC042174 mRNA Translation: AAH42174.1
X67683 mRNA Translation: CAA47914.1
X07695 mRNA Translation: CAA30534.1
X61028 Genomic DNA Translation: CAA43362.1
PIRiI37942
UniGeneiHs.654610
Hs.731814

3D structure databases

ProteinModelPortaliP19013
SMRiP19013
ModBaseiSearch...
MobiDBiSearch...

Protein-protein interaction databases

IntActiP19013, 38 interactors
MINTiP19013
STRINGi9606.ENSP00000448220

PTM databases

iPTMnetiP19013
PhosphoSitePlusiP19013
SwissPalmiP19013

Polymorphism and mutation databases

DMDMi82654947

Proteomic databases

PaxDbiP19013
PeptideAtlasiP19013
PRIDEiP19013
ProteomicsDBi53621

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Genome annotation databases

EnsembliENST00000293774; ENSP00000293774; ENSG00000170477
ENST00000551956; ENSP00000448220; ENSG00000170477
UCSCiuc031qhk.2 human

Organism-specific databases

DisGeNETi3851
EuPathDBiHostDB:ENSG00000170477.12
GeneCardsiKRT4
H-InvDBiHIX0010659
HGNCiHGNC:6441 KRT4
HPAiCAB002154
HPA034881
MalaCardsiKRT4
MIMi123940 gene
193900 phenotype
neXtProtiNX_P19013
Orphaneti171723 White sponge nevus
PharmGKBiPA30229
GenAtlasiSearch...

Phylogenomic databases

eggNOGiENOG410IGG3 Eukaryota
ENOG410ZE7B LUCA
HOGENOMiHOG000230976
HOVERGENiHBG013015
InParanoidiP19013
OrthoDBiEOG091G09KR
PhylomeDBiP19013
TreeFamiTF317854

Enzyme and pathway databases

ReactomeiR-HSA-6805567 Keratinization
R-HSA-6809371 Formation of the cornified envelope
SIGNORiP19013

Miscellaneous databases

ChiTaRSiKRT4 human
PROiPR:P19013
SOURCEiSearch...

Gene expression databases

BgeeiENSG00000170477 Expressed in 114 organ(s), highest expression level in tongue squamous epithelium
CleanExiHS_KRT4
ExpressionAtlasiP19013 baseline and differential
GenevisibleiP19013 HS

Family and domain databases

InterProiView protein in InterPro
IPR001664 IF
IPR018039 IF_conserved
IPR039008 IF_rod_dom
IPR032444 Keratin_2_head
IPR003054 Keratin_II
PANTHERiPTHR23239 PTHR23239, 1 hit
PfamiView protein in Pfam
PF00038 Filament, 1 hit
PF16208 Keratin_2_head, 1 hit
PRINTSiPR01276 TYPE2KERATIN
SMARTiView protein in SMART
SM01391 Filament, 1 hit
PROSITEiView protein in PROSITE
PS00226 IF_ROD_1, 1 hit
PS51842 IF_ROD_2, 1 hit
ProtoNetiSearch...

Entry informationi

Entry nameiK2C4_HUMAN
AccessioniPrimary (citable) accession number: P19013
Secondary accession number(s): F8VS64
, Q6GTR8, Q96LA7, Q9BTL1
Entry historyiIntegrated into UniProtKB/Swiss-Prot: November 1, 1990
Last sequence update: November 22, 2005
Last modified: September 12, 2018
This is version 174 of the entry and version 4 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program
DisclaimerAny medical or genetic information present in this entry is provided for research, educational and informational purposes only. It is not in any way intended to be used as a substitute for professional medical advice, diagnosis, treatment or care.

Miscellaneousi

Keywords - Technical termi

Complete proteome, Reference proteome
UniProt is an ELIXIR core data resource
Main funding by: National Institutes of Health

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