P35900 (K1C20_HUMAN) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Keratin, type I cytoskeletal 20

Alternative name(s):
Cytokeratin-20
Short name=CK-20
Keratin-20
Short name=K20
Protein IT

Gene names

Name:

KRT20

Organism

Homo sapiens (Human) [Reference proteome]

Taxonomic identifier

9606 [NCBI]

Taxonomic lineage

cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Deuterostomia › Chordata › Craniata › Vertebrata › Gnathostomata › Teleostomi › Euteleostomi › Sarcopterygii › Tetrapoda › Amniota › Mammalia › Theria › Eutheria › Euarchontoglires › Primates › Haplorrhini › Simiiformes › Catarrhini › Hominoidea › Hominidae › Homininae › Homo

Protein attributes

Sequence length	424 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Plays a significant role in maintaining keratin filament organization in intestinal epithelia. When phosphorylated, plays a role in the secretion of mucin in the small intestine By similarity. Ref.4 Ref.8
Subunit structure	Heterotetramer of two type I and two type II keratins. Associates with KRT8.
Subcellular location	Cytoplasm Ref.6 Ref.7.
Tissue specificity	Expressed predominantly in the intestinal epithelium. Expressed in luminal cells of colonic mucosa. Also expressed in the Merkel cells of keratinized oral mucosa; specifically at the tips of some rete ridges of the gingival mucosa, in the basal layer of the palatal mucosa and in the taste buds of lingual mucosa. Ref.6 Ref.7
Developmental stage	First detected at embryonic week 8 in individual 'converted' simple epithelial cells of the developing intestinal mucosa. In later fetal stages, synthesis extends over most goblet cells and a variable number of villus enterocytes. In the developing gastric and intestinal mucosa, expressed in all enterocytes and goblet cells as well as certain 'low-differentiated' columnar cells, whereas the neuroendocrine and Paneth cells are negative. Ref.1
Post-translational modification	Hyperphosphorylation at Ser-13 occurs during the early stages of apoptosis but becomes less prominent during the later stages. Phosphorylation at Ser-13 also increases in response to stress brought on by cell injury By similarity. Proteolytically cleaved by caspases during apoptosis. Cleavage occurs at Asp-228. Ref.4
Miscellaneous	There are two types of cytoskeletal and microfibrillar keratin: I (acidic; 40-55 kDa) and II (neutral to basic; 56-70 kDa).
Sequence similarities	Belongs to the intermediate filament family.

Ontologies

Keywords
Biological process	Apoptosis
Cellular component	Cytoplasm Intermediate filament Keratin
Coding sequence diversity	Polymorphism
Domain	Coiled coil
PTM	Phosphoprotein
Technical term	Complete proteome Direct protein sequencing Reference proteome
Gene Ontology (GO)
Biological_process	apoptotic process Inferred from electronic annotation. Source: UniProtKB-KW cellular response to stress Inferred from electronic annotation. Source: Compara intermediate filament organization Inferred from mutant phenotype Ref.8. Source: UniProtKB regulation of protein secretion Inferred from electronic annotation. Source: Compara
Cellular_component	cytoplasm Inferred from direct assay Ref.7. Source: UniProtKB intermediate filament Non-traceable author statement Ref.1. Source: UniProtKB
Molecular_function	structural constituent of cytoskeleton Non-traceable author statement Ref.1. Source: UniProtKB
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 424	424	Keratin, type I cytoskeletal 20		PRO_0000063675
Regions
	Region	1 – 69	69	Head
	Region	70 – 377	308	Rod
	Region	70 – 105	36	Coil 1A
	Region	106 – 123	18	Linker 1
	Region	124 – 215	92	Coil 1B
	Region	216 – 238	23	Linker 12
	Region	239 – 377	139	Coil 2
	Region	378 – 424	47	Tail
Sites
	Site	228 – 229	2	Cleavage; by caspases
Amino acid modifications
	Modified residue	13	1	Phosphoserine; by MAPKAPK2, MAPKAPK3 and PKC Ref.4
	Modified residue	14	1	Phosphoserine By similarity
Natural variations
	Natural variant	4	1	S → R in a colorectal cancer sample; somatic mutation. Ref.9		VAR_036367
	Natural variant	129	1	S → N. Ref.2 Corresponds to variant rs7212483 [ dbSNP | Ensembl ].		VAR_024489
	Natural variant	214	1	G → C Found in a renal cell carcinoma sample; somatic mutation. Ref.10		VAR_064726
Experimental info
	Mutagenesis	13	1	S → A: Promotes keratin filament disassembly. Ref.4
	Mutagenesis	14	1	S → A: No effect on keratin filament organization. Ref.4
	Mutagenesis	80	1	R → H: Leads to collapsed filaments. Ref.8
	Sequence conflict	161	1	T → S in CAA51914. Ref.5
	Sequence conflict	349	1	Q → P in CAA51914. Ref.5
	Sequence conflict	398	1	R → T in CAA51914. Ref.5

Sequences

	Sequence		Length	Mass (Da)
	P35900 [UniParc]. Last modified June 1, 1994. Version 1. Checksum: A8EF5A518C73CCE5	FASTA	424	48,487
	10 20 30 40 50 60 MDFSRRSFHR SLSSSLQAPV VSTVGMQRLG TTPSVYGGAG GRGIRISNSR HTVNYGSDLT 70 80 90 100 110 120 GGGDLFVGNE KMAMQNLNDR LASYLEKVRT LEQSNSKLEV QIKQWYETNA PRAGRDYSAY 130 140 150 160 170 180 YRQIEELRSQ IKDAQLQNAR CVLQIDNAKL AAEDFRLKYE TERGIRLTVE ADLQGLNKVF 190 200 210 220 230 240 DDLTLHKTDL EIQIEELNKD LALLKKEHQE EVDGLHKHLG NTVNVEVDAA PGLNLGVIMN 250 260 270 280 290 300 EMRQKYEVMA QKNLQEAKEQ FERQTAVLQQ QVTVNTEELK GTEVQLTELR RTSQSLEIEL 310 320 330 340 350 360 QSHLSMKESL EHTLEETKAR YSSQLANLQS LLSSLEAQLM QIRSNMERQN NEYHILLDIK 370 380 390 400 410 420 TRLEQEIATY RRLLEGEDVK TTEYQLSTLE ERDIKKTRKI KTVVQEVVDG KVVSSEVKEV EENI

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"The human gene encoding cytokeratin 20 and its expression during fetal development and in gastrointestinal carcinomas." Moll R., Zimbelmann R., Goldschmidt M.D., Keith M., Laufer J., Kasper M., Koch P.J., Franke W.W. Differentiation 53:75-93(1993) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], DEVELOPMENTAL STAGE. Tissue: Intestine.
[2]	"Complete sequencing and characterization of 21,243 full-length human cDNAs." Ota T., Suzuki Y., Nishikawa T., Otsuki T., Sugiyama T., Irie R., Wakamatsu A., Hayashi K., Sato H., Nagai K., Kimura K., Makita H., Sekine M., Obayashi M., Nishi T., Shibahara T., Tanaka T., Ishii S. , Yamamoto J., Saito K., Kawai Y., Isono Y., Nakamura Y., Nagahari K., Murakami K., Yasuda T., Iwayanagi T., Wagatsuma M., Shiratori A., Sudo H., Hosoiri T., Kaku Y., Kodaira H., Kondo H., Sugawara M., Takahashi M., Kanda K., Yokoi T., Furuya T., Kikkawa E., Omura Y., Abe K., Kamihara K., Katsuta N., Sato K., Tanikawa M., Yamazaki M., Ninomiya K., Ishibashi T., Yamashita H., Murakawa K., Fujimori K., Tanai H., Kimata M., Watanabe M., Hiraoka S., Chiba Y., Ishida S., Ono Y., Takiguchi S., Watanabe S., Yosida M., Hotuta T., Kusano J., Kanehori K., Takahashi-Fujii A., Hara H., Tanase T.-O., Nomura Y., Togiya S., Komai F., Hara R., Takeuchi K., Arita M., Imose N., Musashino K., Yuuki H., Oshima A., Sasaki N., Aotsuka S., Yoshikawa Y., Matsunawa H., Ichihara T., Shiohata N., Sano S., Moriya S., Momiyama H., Satoh N., Takami S., Terashima Y., Suzuki O., Nakagawa S., Senoh A., Mizoguchi H., Goto Y., Shimizu F., Wakebe H., Hishigaki H., Watanabe T., Sugiyama A., Takemoto M., Kawakami B., Yamazaki M., Watanabe K., Kumagai A., Itakura S., Fukuzumi Y., Fujimori Y., Komiyama M., Tashiro H., Tanigami A., Fujiwara T., Ono T., Yamada K., Fujii Y., Ozaki K., Hirao M., Ohmori Y., Kawabata A., Hikiji T., Kobatake N., Inagaki H., Ikema Y., Okamoto S., Okitani R., Kawakami T., Noguchi S., Itoh T., Shigeta K., Senba T., Matsumura K., Nakajima Y., Mizuno T., Morinaga M., Sasaki M., Togashi T., Oyama M., Hata H., Watanabe M., Komatsu T., Mizushima-Sugano J., Satoh T., Shirai Y., Takahashi Y., Nakagawa K., Okumura K., Nagase T., Nomura N., Kikuchi H., Masuho Y., Yamashita R., Nakai K., Yada T., Nakamura Y., Ohara O., Isogai T., Sugano S. Nat. Genet. 36:40-45(2004) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA], VARIANT ASN-129. Tissue: Small intestine.
[3]	"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)." The MGC Project Team Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
[4]	"Keratin 20 serine 13 phosphorylation is a stress and intestinal goblet cell marker." Zhou Q., Cadrin M., Herrmann H., Chen C.-H., Chalkley R.J., Burlingame A.L., Omary M.B. J. Biol. Chem. 281:16453-16461(2006) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 11-28, FUNCTION, INTERACTION WITH KRT8, PHOSPHORYLATION AT SER-13, CLEAVAGE AT ASP-228, MUTAGENESIS OF SER-13 AND SER-14.
[5]	"Differential localization by in situ hybridization of distinct keratin mRNA species during intestinal epithelial cell development and differentiation." Calnek D., Quaroni A. Differentiation 53:95-104(1993) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA] OF 86-424. Tissue: Intestine.
[6]	"Identification of protein IT of the intestinal cytoskeleton as a novel type I cytokeratin with unusual properties and expression patterns." Moll R., Schiller D.L., Franke W.W. J. Cell Biol. 111:567-580(1990) [PubMed] [Europe PMC] [Abstract] Cited for: IDENTIFICATION, SUBCELLULAR LOCATION, TISSUE SPECIFICITY.
[7]	"An immunohistological study of cytokeratin 20 in human and mammalian oral epithelium." Barrett A.W., Cort E.M., Patel P., Berkovitz B.K.B. Arch. Oral Biol. 45:879-887(2000) [PubMed] [Europe PMC] [Abstract] Cited for: INTERACTION WITH KRT8, SUBCELLULAR LOCATION, TISSUE SPECIFICITY.
[8]	"Keratin 20 helps maintain intermediate filament organization in intestinal epithelia." Zhou Q., Toivola D.M., Feng N., Greenberg H.B., Franke W.W., Omary M.B. Mol. Biol. Cell 14:2959-2971(2003) [PubMed] [Europe PMC] [Abstract] Cited for: FUNCTION, MUTAGENESIS OF ARG-80.
[9]	"The consensus coding sequences of human breast and colorectal cancers." Sjoeblom T., Jones S., Wood L.D., Parsons D.W., Lin J., Barber T.D., Mandelker D., Leary R.J., Ptak J., Silliman N., Szabo S., Buckhaults P., Farrell C., Meeh P., Markowitz S.D., Willis J., Dawson D., Willson J.K.V. , Gazdar A.F., Hartigan J., Wu L., Liu C., Parmigiani G., Park B.H., Bachman K.E., Papadopoulos N., Vogelstein B., Kinzler K.W., Velculescu V.E. Science 314:268-274(2006) [PubMed] [Europe PMC] [Abstract] Cited for: VARIANT [LARGE SCALE ANALYSIS] ARG-4.
[10]	"Exome sequencing identifies frequent mutation of the SWI/SNF complex gene PBRM1 in renal carcinoma." Varela I., Tarpey P., Raine K., Huang D., Ong C.K., Stephens P., Davies H., Jones D., Lin M.L., Teague J., Bignell G., Butler A., Cho J., Dalgliesh G.L., Galappaththige D., Greenman C., Hardy C., Jia M. , Latimer C., Lau K.W., Marshall J., McLaren S., Menzies A., Mudie L., Stebbings L., Largaespada D.A., Wessels L.F.A., Richard S., Kahnoski R.J., Anema J., Tuveson D.A., Perez-Mancera P.A., Mustonen V., Fischer A., Adams D.J., Rust A., Chan-On W., Subimerb C., Dykema K., Furge K., Campbell P.J., Teh B.T., Stratton M.R., Futreal P.A. Nature 469:539-542(2011) [PubMed] [Europe PMC] [Abstract] Cited for: VARIANT CYS-214.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	X73501 Genomic DNA. Translation: CAA51913.1. AK312744 mRNA. Translation: BAG35614.1. BC031559 mRNA. Translation: AAH31559.1. X73502 mRNA. Translation: CAA51914.1.
IPI	IPI00021298.
PIR	S37780.
RefSeq	NP_061883.1. NM_019010.2.
UniGene	Hs.84905.
3D structure databases
ProteinModelPortal	P35900.
ModBase	Search...
Protein-protein interaction databases
IntAct	P35900. 15 interactions.
MINT	MINT-1445560.
STRING	9606.ENSP00000167588.
PTM databases
PhosphoSite	P35900.
Polymorphism databases
DMDM	547750.
Proteomic databases
PaxDb	P35900.
PRIDE	P35900.
Protocols and materials databases
DNASU	54474.
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
Ensembl	ENST00000167588; ENSP00000167588; ENSG00000171431. ENST00000576098; ENSP00000460501; ENSG00000263057.
GeneID	54474.
KEGG	hsa:54474.
UCSC	uc002hvl.3. human.
Organism-specific databases
CTD	54474.
GeneCards	GC17M039030.
HGNC	HGNC:20412. KRT20.
HPA	CAB000032. HPA024309. HPA024684. HPA027236.
MIM	608218. gene.
neXtProt	NX_P35900.
PharmGKB	PA134938907.
GenAtlas	Search...
Phylogenomic databases
eggNOG	NOG149615.
HOGENOM	HOG000230975.
HOVERGEN	HBG013015.
InParanoid	P35900.
KO	K07604.
OMA	QIKQWYE.
OrthoDB	EOG4NKBVQ.
PhylomeDB	P35900.
Gene expression databases
Bgee	P35900.
CleanEx	HS_KRT20.
Genevestigator	P35900.
GermOnline	ENSG00000171431. Homo sapiens.
Family and domain databases
InterPro	IPR016044. F. IPR001664. IF. IPR018039. Intermediate_filament_CS. IPR002957. Keratin_I. [Graphical view]
PANTHER	PTHR23239. PTHR23239. 1 hit.
Pfam	PF00038. Filament. 1 hit. [Graphical view]
PRINTS	PR01248. TYPE1KERATIN.
PROSITE	PS00226. IF. 1 hit. [Graphical view]
ProtoNet	Search...
Other
GenomeRNAi	54474.
NextBio	56776.
SOURCE	Search...

Entry information

Entry name

K1C20_HUMAN

Accession

Primary (citable) accession number: P35900
Secondary accession number(s): B2R6W7

Entry history

Integrated into UniProtKB/Swiss-Prot:	June 1, 1994
Last sequence update:	June 1, 1994
Last modified:	May 1, 2013
This is version 125 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program

Disclaimer

Any 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.