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Protein

Keratin, type I cytoskeletal 9

Gene

KRT9

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

Functioni

May serve an important special function either in the mature palmar and plantar skin tissue or in the morphogenetic program of the formation of these tissues. Plays a role in keratin filament assembly.2 Publications

Miscellaneous

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

Caution

Was originally thought to be a 60 kDa chain of placental scatter protein.1 Publication

GO - Molecular functioni

  • structural constituent of cytoskeleton Source: ProtInc

GO - Biological processi

  • cornification Source: Reactome
  • epidermis development Source: ProtInc
  • intermediate filament organization Source: UniProtKB
  • keratinization Source: Reactome
  • skin development Source: UniProtKB

Enzyme and pathway databases

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

Names & Taxonomyi

Protein namesi
Recommended name:
Keratin, type I cytoskeletal 9
Alternative name(s):
Cytokeratin-9
Short name:
CK-9
Keratin-9
Short name:
K9
Gene namesi
Name:KRT9
OrganismiHomo sapiens (Human)
Taxonomic identifieri9606 [NCBI]
Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresPrimatesHaplorrhiniCatarrhiniHominidaeHomo
Proteomesi
  • UP000005640 Componenti: Chromosome 17

Organism-specific databases

EuPathDBiHostDB:ENSG00000171403.9
HGNCiHGNC:6447 KRT9
MIMi607606 gene
neXtProtiNX_P35527

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

Keratoderma, palmoplantar, epidermolytic (EPPK)23 Publications
The disease is caused by mutations affecting the gene represented in this entry.
Disease descriptionA dermatological disorder characterized by diffuse thickening of the epidermis on the entire surface of palms and soles sharply bordered with erythematous margins. Some patients may present knuckle pads, thick pads of skin appearing over the proximal phalangeal joints.
See also OMIM:144200
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_071977157M → K in EPPK. 1 PublicationCorresponds to variant dbSNP:rs59510579EnsemblClinVar.1
Natural variantiVAR_036805157M → R in EPPK. 1 PublicationCorresponds to variant dbSNP:rs59510579EnsemblClinVar.1
Natural variantiVAR_010499157M → T in EPPK. 2 PublicationsCorresponds to variant dbSNP:rs59510579EnsemblClinVar.1
Natural variantiVAR_010500157M → V in EPPK. 3 PublicationsCorresponds to variant dbSNP:rs58597584EnsemblClinVar.1
Natural variantiVAR_035438160L → F in EPPK; with knuckle pads. 1 PublicationCorresponds to variant dbSNP:rs28940896EnsemblClinVar.1
Natural variantiVAR_010501160L → V in EPPK. 1 PublicationCorresponds to variant dbSNP:rs28940896EnsemblClinVar.1
Natural variantiVAR_036806161N → H in EPPK. 2 PublicationsCorresponds to variant dbSNP:rs59296273EnsemblClinVar.1
Natural variantiVAR_036807161N → I in EPPK. 2 PublicationsCorresponds to variant dbSNP:rs56707768EnsemblClinVar.1
Natural variantiVAR_003822161N → K in EPPK. 1 PublicationCorresponds to variant dbSNP:rs57536312EnsemblClinVar.1
Natural variantiVAR_010502161N → S in EPPK. 2 PublicationsCorresponds to variant dbSNP:rs56707768EnsemblClinVar.1
Natural variantiVAR_010503161N → Y in EPPK. 1 PublicationCorresponds to variant dbSNP:rs59296273EnsemblClinVar.1
Natural variantiVAR_036808163R → P in EPPK. 1 PublicationCorresponds to variant dbSNP:rs57758262EnsemblClinVar.1
Natural variantiVAR_003823163R → Q in EPPK. 6 PublicationsCorresponds to variant dbSNP:rs57758262EnsemblClinVar.1
Natural variantiVAR_003824163R → W in EPPK. 5 PublicationsCorresponds to variant dbSNP:rs59616921EnsemblClinVar.1
Natural variantiVAR_036809167Y → WL in EPPK. 1
Natural variantiVAR_003825168L → S in EPPK. 1 PublicationCorresponds to variant dbSNP:rs61157095EnsemblClinVar.1
Natural variantiVAR_035439171V → M in EPPK. 1 PublicationCorresponds to variant dbSNP:rs57019720EnsemblClinVar.1
Natural variantiVAR_010504172Q → P in EPPK. 1 PublicationCorresponds to variant dbSNP:rs59878153EnsemblClinVar.1
Natural variantiVAR_071978406C → R in EPPK. 1 PublicationCorresponds to variant dbSNP:rs77688767EnsemblClinVar.1
Natural variantiVAR_071979454Y → H in EPPK. 1 PublicationCorresponds to variant dbSNP:rs267607420EnsemblClinVar.1
Natural variantiVAR_036810458L → F in EPPK. 1 PublicationCorresponds to variant dbSNP:rs58120120EnsemblClinVar.1
Natural variantiVAR_071980458L → P in EPPK. 1 Publication1

Mutagenesis

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Mutagenesisi163R → QHA: Leads to aggregate formation. 1 Publication1

Keywords - Diseasei

Disease mutation, Palmoplantar keratoderma

Organism-specific databases

DisGeNETi3857
MalaCardsiKRT9
MIMi144200 phenotype
149100 phenotype
OpenTargetsiENSG00000171403
Orphaneti2199 Epidermolytic palmoplantar keratoderma
PharmGKBiPA30235

Polymorphism and mutation databases

BioMutaiKRT9
DMDMi239938886

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00000636401 – 623Keratin, type I cytoskeletal 9Add BLAST623

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Modified residuei14PhosphoserineBy similarity1
Modified residuei57PhosphoserineBy similarity1

Keywords - PTMi

Phosphoprotein

Proteomic databases

EPDiP35527
PaxDbiP35527
PeptideAtlasiP35527
PRIDEiP35527
TopDownProteomicsiP35527

2D gel databases

DOSAC-COBS-2DPAGEP35527

PTM databases

iPTMnetiP35527
PhosphoSitePlusiP35527
SwissPalmiP35527

Expressioni

Tissue specificityi

Expressed in the terminally differentiated epidermis of palms and soles.1 Publication

Inductioni

Induced by intrinsic regulatory mechanisms and by extrinsic signals from a subset of dermal palmoplantar fibroblasts.1 Publication

Gene expression databases

BgeeiENSG00000171403
CleanExiHS_KRT9
ExpressionAtlasiP35527 baseline and differential
GenevisibleiP35527 HS

Interactioni

Subunit structurei

Heterotetramer of two type I and two type II keratins.

Protein-protein interaction databases

BioGridi110055, 50 interactors
IntActiP35527, 19 interactors
MINTiP35527
STRINGi9606.ENSP00000246662

Structurei

3D structure databases

ProteinModelPortaliP35527
SMRiP35527
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Domaini153 – 465IF rodPROSITE-ProRule annotationAdd BLAST313

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni1 – 152HeadAdd BLAST152
Regioni153 – 188Coil 1AAdd BLAST36
Regioni189 – 207Linker 1Add BLAST19
Regioni208 – 299Coil 1BAdd BLAST92
Regioni300 – 322Linker 12Add BLAST23
Regioni323 – 461Coil 2Add BLAST139
Regioni462 – 623TailAdd BLAST162

Compositional bias

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Compositional biasi15 – 26Poly-GlyAdd BLAST12

Sequence similaritiesi

Belongs to the intermediate filament family.PROSITE-ProRule annotation

Keywords - Domaini

Coiled coil

Phylogenomic databases

eggNOGiENOG410IEYG Eukaryota
ENOG4111C5Z LUCA
GeneTreeiENSGT00910000144130
HOGENOMiHOG000230975
HOVERGENiHBG013015
InParanoidiP35527
KOiK07604
OMAiEMQYETL
OrthoDBiEOG091G087I
PhylomeDBiP35527
TreeFamiTF332742

Family and domain databases

InterProiView protein in InterPro
IPR001664 IF
IPR018039 IF_conserved
IPR039008 IF_rod_dom
IPR002957 Keratin_I
PANTHERiPTHR23239 PTHR23239, 3 hits
PfamiView protein in Pfam
PF00038 Filament, 1 hit
PRINTSiPR01248 TYPE1KERATIN
SMARTiView protein in SMART
SM01391 Filament, 1 hit
PROSITEiView protein in PROSITE
PS00226 IF_ROD_1, 1 hit
PS51842 IF_ROD_2, 1 hit

Sequencei

Sequence statusi: Complete.

P35527-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MSCRQFSSSY LSRSGGGGGG GLGSGGSIRS SYSRFSSSGG GGGGGRFSSS
60 70 80 90 100
SGYGGGSSRV CGRGGGGSFG YSYGGGSGGG FSASSLGGGF GGGSRGFGGA
110 120 130 140 150
SGGGYSSSGG FGGGFGGGSG GGFGGGYGSG FGGFGGFGGG AGGGDGGILT
160 170 180 190 200
ANEKSTMQEL NSRLASYLDK VQALEEANND LENKIQDWYD KKGPAAIQKN
210 220 230 240 250
YSPYYNTIDD LKDQIVDLTV GNNKTLLDID NTRMTLDDFR IKFEMEQNLR
260 270 280 290 300
QGVDADINGL RQVLDNLTME KSDLEMQYET LQEELMALKK NHKEEMSQLT
310 320 330 340 350
GQNSGDVNVE INVAPGKDLT KTLNDMRQEY EQLIAKNRKD IENQYETQIT
360 370 380 390 400
QIEHEVSSSG QEVQSSAKEV TQLRHGVQEL EIELQSQLSK KAALEKSLED
410 420 430 440 450
TKNRYCGQLQ MIQEQISNLE AQITDVRQEI ECQNQEYSLL LSIKMRLEKE
460 470 480 490 500
IETYHNLLEG GQEDFESSGA GKIGLGGRGG SGGSYGRGSR GGSGGSYGGG
510 520 530 540 550
GSGGGYGGGS GSRGGSGGSY GGGSGSGGGS GGGYGGGSGG GHSGGSGGGH
560 570 580 590 600
SGGSGGNYGG GSGSGGGSGG GYGGGSGSRG GSGGSHGGGS GFGGESGGSY
610 620
GGGEEASGSG GGYGGGSGKS SHS
Length:623
Mass (Da):62,064
Last modified:June 16, 2009 - v3
Checksum:i45C833749B63873D
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti12 – 13SR → T in AAC60619 (PubMed:7507869).Curated2
Sequence conflicti12 – 13SR → T in CAA52924 (PubMed:7512862).Curated2
Sequence conflicti41G → R in AAC60619 (PubMed:7507869).Curated1
Sequence conflicti41G → R in CAA82315 (PubMed:7507869).Curated1
Sequence conflicti41G → R in CAA52924 (PubMed:7512862).Curated1
Sequence conflicti134F → L in AAC60619 (PubMed:7507869).Curated1
Sequence conflicti134F → L in CAA82315 (PubMed:7507869).Curated1
Sequence conflicti134F → L in CAA52924 (PubMed:7512862).Curated1
Sequence conflicti157 – 170MQELN…SYLDK → HLGAGSTPITASQP in AAI21171 (PubMed:15489334).CuratedAdd BLAST14

Natural variant

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Natural variantiVAR_071977157M → K in EPPK. 1 PublicationCorresponds to variant dbSNP:rs59510579EnsemblClinVar.1
Natural variantiVAR_036805157M → R in EPPK. 1 PublicationCorresponds to variant dbSNP:rs59510579EnsemblClinVar.1
Natural variantiVAR_010499157M → T in EPPK. 2 PublicationsCorresponds to variant dbSNP:rs59510579EnsemblClinVar.1
Natural variantiVAR_010500157M → V in EPPK. 3 PublicationsCorresponds to variant dbSNP:rs58597584EnsemblClinVar.1
Natural variantiVAR_035438160L → F in EPPK; with knuckle pads. 1 PublicationCorresponds to variant dbSNP:rs28940896EnsemblClinVar.1
Natural variantiVAR_010501160L → V in EPPK. 1 PublicationCorresponds to variant dbSNP:rs28940896EnsemblClinVar.1
Natural variantiVAR_036806161N → H in EPPK. 2 PublicationsCorresponds to variant dbSNP:rs59296273EnsemblClinVar.1
Natural variantiVAR_036807161N → I in EPPK. 2 PublicationsCorresponds to variant dbSNP:rs56707768EnsemblClinVar.1
Natural variantiVAR_003822161N → K in EPPK. 1 PublicationCorresponds to variant dbSNP:rs57536312EnsemblClinVar.1
Natural variantiVAR_010502161N → S in EPPK. 2 PublicationsCorresponds to variant dbSNP:rs56707768EnsemblClinVar.1
Natural variantiVAR_010503161N → Y in EPPK. 1 PublicationCorresponds to variant dbSNP:rs59296273EnsemblClinVar.1
Natural variantiVAR_036808163R → P in EPPK. 1 PublicationCorresponds to variant dbSNP:rs57758262EnsemblClinVar.1
Natural variantiVAR_003823163R → Q in EPPK. 6 PublicationsCorresponds to variant dbSNP:rs57758262EnsemblClinVar.1
Natural variantiVAR_003824163R → W in EPPK. 5 PublicationsCorresponds to variant dbSNP:rs59616921EnsemblClinVar.1
Natural variantiVAR_036809167Y → WL in EPPK. 1
Natural variantiVAR_003825168L → S in EPPK. 1 PublicationCorresponds to variant dbSNP:rs61157095EnsemblClinVar.1
Natural variantiVAR_035439171V → M in EPPK. 1 PublicationCorresponds to variant dbSNP:rs57019720EnsemblClinVar.1
Natural variantiVAR_010504172Q → P in EPPK. 1 PublicationCorresponds to variant dbSNP:rs59878153EnsemblClinVar.1
Natural variantiVAR_071978406C → R in EPPK. 1 PublicationCorresponds to variant dbSNP:rs77688767EnsemblClinVar.1
Natural variantiVAR_071979454Y → H in EPPK. 1 PublicationCorresponds to variant dbSNP:rs267607420EnsemblClinVar.1
Natural variantiVAR_036810458L → F in EPPK. 1 PublicationCorresponds to variant dbSNP:rs58120120EnsemblClinVar.1
Natural variantiVAR_071980458L → P in EPPK. 1 Publication1

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
Z29074 mRNA Translation: CAA82315.1
S69510 mRNA Translation: AAC60619.1
X75015 Genomic DNA Translation: CAA52924.1
AC019349 Genomic DNA No translation available.
AB001594 mRNA Translation: BAA19418.1
BC121170 mRNA Translation: AAI21171.1
CCDSiCCDS32654.1
PIRiI37984
RefSeqiNP_000217.2, NM_000226.3
UniGeneiHs.654569

Genome annotation databases

EnsembliENST00000246662; ENSP00000246662; ENSG00000171403
GeneIDi3857
KEGGihsa:3857
UCSCiuc002hxe.5 human

Similar proteinsi

Entry informationi

Entry nameiK1C9_HUMAN
AccessioniPrimary (citable) accession number: P35527
Secondary accession number(s): O00109, Q0IJ47, Q14665
Entry historyiIntegrated into UniProtKB/Swiss-Prot: June 1, 1994
Last sequence update: June 16, 2009
Last modified: May 23, 2018
This is version 183 of the entry and version 3 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, Direct protein sequencing, Reference proteome

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