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Entry version 108 (02 Jun 2021)
Sequence version 2 (19 Sep 2002)
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Protein

Keratin, type I cytoskeletal 20

Gene

Krt20

Organism
Rattus norvegicus (Rat)
Status
Reviewed-Annotation score:

Annotation score:4 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the 'correct annotation' for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
-Experimental evidence at protein leveli <p>This indicates the type of evidence that supports the existence of the protein. Note that the 'protein existence' evidence does not give information on the accuracy or correctness of the sequence(s) displayed.<p><a href='/help/protein_existence' target='_top'>More...</a></p>

<p>This section provides any useful information about the protein, mostly biological knowledge.<p><a href='/help/function_section' target='_top'>More...</a></p>Functioni

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).

By similarity

Miscellaneous

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

<p>The <a href="http://www.geneontology.org/">Gene Ontology (GO)</a> project provides a set of hierarchical controlled vocabulary split into 3 categories:<p><a href='/help/gene_ontology' target='_top'>More...</a></p>GO - Molecular functioni

GO - Biological processi

<p>UniProtKB Keywords constitute a <a href="http://www.uniprot.org/keywords">controlled vocabulary</a> with a hierarchical structure. Keywords summarise the content of a UniProtKB entry and facilitate the search for proteins of interest.<p><a href='/help/keywords' target='_top'>More...</a></p>Keywordsi

Biological processApoptosis

Enzyme and pathway databases

Reactome - a knowledgebase of biological pathways and processes

More...
Reactomei
R-RNO-6805567, Keratinization
R-RNO-6809371, Formation of the cornified envelope

<p>This section provides information about the protein and gene name(s) and synonym(s) and about the organism that is the source of the protein sequence.<p><a href='/help/names_and_taxonomy_section' target='_top'>More...</a></p>Names & Taxonomyi

<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section provides an exhaustive list of all names of the protein, from commonly used to obsolete, to allow unambiguous identification of a protein.<p><a href='/help/protein_names' target='_top'>More...</a></p>Protein namesi
Recommended name:
Keratin, type I cytoskeletal 20
Alternative name(s):
Cytokeratin-20
Short name:
CK-20
Cytokeratin-21
Short name:
CK-21
Keratin-20
Short name:
K20
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section indicates the name(s) of the gene(s) that code for the protein sequence(s) described in the entry. Four distinct tokens exist: 'Name', 'Synonyms', 'Ordered locus names' and 'ORF names'.<p><a href='/help/gene_name' target='_top'>More...</a></p>Gene namesi
Name:Krt20
Synonyms:Krt21
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section provides information on the name(s) of the organism that is the source of the protein sequence.<p><a href='/help/organism-name' target='_top'>More...</a></p>OrganismiRattus norvegicus (Rat)
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section shows the unique identifier assigned by the NCBI to the source organism of the protein. This is known as the 'taxonomic identifier' or 'taxid'.<p><a href='/help/taxonomic_identifier' target='_top'>More...</a></p>Taxonomic identifieri10116 [NCBI]
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section contains the taxonomic hierarchical classification lineage of the source organism. It lists the nodes as they appear top-down in the taxonomic tree, with the more general grouping listed first.<p><a href='/help/taxonomic_lineage' target='_top'>More...</a></p>Taxonomic lineageiEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiMammaliaEutheriaEuarchontogliresGliresRodentiaMyomorphaMuroideaMuridaeMurinaeRattus
<p>This subsection of the <a href="http://www.uniprot.org/help/names%5Fand%5Ftaxonomy%5Fsection">Names and taxonomy</a> section is present for entries that are part of a <a href="http://www.uniprot.org/proteomes">proteome</a>, i.e. of a set of proteins thought to be expressed by organisms whose genomes have been completely sequenced.<p><a href='/help/proteomes_manual' target='_top'>More...</a></p>Proteomesi
  • UP000002494 <p>A UniProt <a href="http://www.uniprot.org/manual/proteomes%5Fmanual">proteome</a> can consist of several components.<br></br>The component name refers to the genomic component encoding a set of proteins.<p><a href='/help/proteome_component' target='_top'>More...</a></p> Componenti: Unplaced

Organism-specific databases

Rat genome database

More...
RGDi
628646, Krt20

<p>This section provides information on the location and the topology of the mature protein in the cell.<p><a href='/help/subcellular_location_section' target='_top'>More...</a></p>Subcellular locationi

Keywords - Cellular componenti

Intermediate filament, Keratin

<p>This section describes post-translational modifications (PTMs) and/or processing events.<p><a href='/help/ptm_processing_section' target='_top'>More...</a></p>PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'PTM / Processing' section describes the extent of a polypeptide chain in the mature protein following processing or proteolytic cleavage.<p><a href='/help/chain' target='_top'>More...</a></p>ChainiPRO_00000636761 – 429Keratin, type I cytoskeletal 20Add BLAST429

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'PTM / Processing' section specifies the position and type of each modified residue excluding <a href="http://www.uniprot.org/manual/lipid">lipids</a>, <a href="http://www.uniprot.org/manual/carbohyd">glycans</a> and <a href="http://www.uniprot.org/manual/crosslnk">protein cross-links</a>.<p><a href='/help/mod_res' target='_top'>More...</a></p>Modified residuei13PhosphoserineCombined sources1
Modified residuei16PhosphoserineCombined sources1
Modified residuei26PhosphoserineCombined sources1

<p>This subsection of the <a href="http://www.uniprot.org/help/ptm%5Fprocessing%5Fsection">PTM/processing</a> section describes post-translational modifications (PTMs). This subsection <strong>complements</strong> the information provided at the sequence level or describes modifications for which <strong>position-specific data is not yet available</strong>.<p><a href='/help/post-translational_modification' target='_top'>More...</a></p>Post-translational modificationi

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).By similarity
Proteolytically cleaved by caspases during apoptosis. Cleavage occurs at Asp-233 (By similarity).By similarity

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection describes interesting single amino acid sites on the sequence that are not defined in any other subsection. This subsection can be displayed in different sections ('Function', 'PTM / Processing', 'Pathology and Biotech') according to its content.<p><a href='/help/site' target='_top'>More...</a></p>Sitei233 – 234Cleavage; by caspasesBy similarity2

Keywords - PTMi

Phosphoprotein

Proteomic databases

jPOST - Japan Proteome Standard Repository/Database

More...
jPOSTi
P25030

PRoteomics IDEntifications database

More...
PRIDEi
P25030

PTM databases

iPTMnet integrated resource for PTMs in systems biology context

More...
iPTMneti
P25030

Comprehensive resource for the study of protein post-translational modifications (PTMs) in human, mouse and rat.

More...
PhosphoSitePlusi
P25030

<p>This section provides information on the expression of a gene at the mRNA or protein level in cells or in tissues of multicellular organisms.<p><a href='/help/expression_section' target='_top'>More...</a></p>Expressioni

<p>This subsection of the 'Expression' section provides information on the expression of a gene at the mRNA or protein level in cells or in tissues of multicellular organisms. By default, the information is derived from experiments at the mRNA level, unless specified 'at protein level'.<br></br>Examples: <a href="http://www.uniprot.org/uniprot/P92958#expression">P92958</a>, <a href="http://www.uniprot.org/uniprot/Q8TDN4#expression">Q8TDN4</a>, <a href="http://www.uniprot.org/uniprot/O14734#expression">O14734</a><p><a href='/help/tissue_specificity' target='_top'>More...</a></p>Tissue specificityi

Expressed predominantly in the intestinal epithelium in differentiated villus cells.2 Publications

<p>This subsection of the 'Expression' section provides information on the expression of the gene product at various stages of a cell, tissue or organism development. By default, the information is derived from experiments at the mRNA level, unless specified 'at the protein level'.<p><a href='/help/developmental_stage' target='_top'>More...</a></p>Developmental stagei

Becomes apparent upon completion of villus formation at 20 days gestation (2 days before birth) and is expressed by the entire epithelium of the villus.1 Publication

<p>This section provides information on the quaternary structure of a protein and on interaction(s) with other proteins or protein complexes.<p><a href='/help/interaction_section' target='_top'>More...</a></p>Interactioni

<p>This subsection of the <a href="http://www.uniprot.org/help/interaction%5Fsection">'Interaction'</a> section provides information about the protein quaternary structure and interaction(s) with other proteins or protein complexes (with the exception of physiological receptor-ligand interactions which are annotated in the <a href="http://www.uniprot.org/help/function%5Fsection">'Function'</a> section).<p><a href='/help/subunit_structure' target='_top'>More...</a></p>Subunit structurei

Heterotetramer of two type I and two type II keratins. Associates with KRT8 (By similarity).

By similarity

Protein-protein interaction databases

Protein interaction database and analysis system

More...
IntActi
P25030, 3 interactors

<p>This section provides information on the tertiary and secondary structure of a protein.<p><a href='/help/structure_section' target='_top'>More...</a></p>Structurei

3D structure databases

SWISS-MODEL Repository - a database of annotated 3D protein structure models

More...
SMRi
P25030

Database of comparative protein structure models

More...
ModBasei
Search...

<p>This section provides information on sequence similarities with other proteins and the domain(s) present in a protein.<p><a href='/help/family_and_domains_section' target='_top'>More...</a></p>Family & Domainsi

Domains and Repeats

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the <a href="http://www.uniprot.org/help/family%5Fand%5Fdomains%5Fsection">Family and Domains</a> section describes the position and type of a domain, which is defined as a specific combination of secondary structures organized into a characteristic three-dimensional structure or fold.<p><a href='/help/domain' target='_top'>More...</a></p>Domaini75 – 386IF rodPROSITE-ProRule annotationAdd BLAST312

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'Family and Domains' section describes a region of interest that cannot be described in other subsections.<p><a href='/help/region' target='_top'>More...</a></p>Regioni1 – 74HeadAdd BLAST74
Regioni1 – 26DisorderedSequence analysisAdd BLAST26
Regioni75 – 110Coil 1AAdd BLAST36
Regioni111 – 128Linker 1Add BLAST18
Regioni129 – 220Coil 1BAdd BLAST92
Regioni221 – 243Linker 12Add BLAST23
Regioni244 – 382Coil 2Add BLAST139
Regioni383 – 429TailAdd BLAST47

Compositional bias

Feature keyPosition(s)DescriptionActionsGraphical viewLength
<p>This subsection of the 'Family and Domains' section describes the position of regions of compositional bias within the protein and the particular type of amino acids that are over-represented within those regions.<p><a href='/help/compbias' target='_top'>More...</a></p>Compositional biasi8 – 26Polar residuesSequence analysisAdd BLAST19

<p>This subsection of the 'Family and domains' section provides information about the sequence similarity with other proteins.<p><a href='/help/sequence_similarities' target='_top'>More...</a></p>Sequence similaritiesi

Belongs to the intermediate filament family.PROSITE-ProRule annotation

Keywords - Domaini

Coiled coil

Phylogenomic databases

InParanoid: Eukaryotic Ortholog Groups

More...
InParanoidi
P25030

Identification of Orthologs from Complete Genome Data

More...
OMAi
YSAYYKQ

Database of Orthologous Groups

More...
OrthoDBi
798081at2759

Database for complete collections of gene phylogenies

More...
PhylomeDBi
P25030

Family and domain databases

Gene3D Structural and Functional Annotation of Protein Families

More...
Gene3Di
1.20.5.1160, 1 hit

Integrated resource of protein families, domains and functional sites

More...
InterProi
View protein in InterPro
IPR018039, IF_conserved
IPR039008, IF_rod_dom
IPR042180, IF_rod_dom_coil1B
IPR002957, Keratin_I

The PANTHER Classification System

More...
PANTHERi
PTHR23239, PTHR23239, 1 hit

Pfam protein domain database

More...
Pfami
View protein in Pfam
PF00038, Filament, 1 hit

Protein Motif fingerprint database; a protein domain database

More...
PRINTSi
PR01248, TYPE1KERATIN

Simple Modular Architecture Research Tool; a protein domain database

More...
SMARTi
View protein in SMART
SM01391, Filament, 1 hit

PROSITE; a protein domain and family database

More...
PROSITEi
View protein in PROSITE
PS00226, IF_ROD_1, 1 hit
PS51842, IF_ROD_2, 1 hit

<p>This section displays by default the canonical protein sequence and upon request all isoforms described in the entry. It also includes information pertinent to the sequence(s), including <a href="http://www.uniprot.org/help/sequence%5Flength">length</a> and <a href="http://www.uniprot.org/help/sequences">molecular weight</a>. The information is filed in different subsections. The current subsections and their content are listed below:<p><a href='/help/sequences_section' target='_top'>More...</a></p>Sequence (1+)i

<p>This subsection of the <a href="http://www.uniprot.org/help/sequences%5Fsection">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical%5Fand%5Fisoforms">canonical sequence</a> displayed by default in the entry is complete or not.<p><a href='/help/sequence_status' target='_top'>More...</a></p>Sequence statusi: Complete.

This entry has 1 described isoform and 3 potential isoforms that are computationally mapped.Show allAlign All

P25030-1 [UniParc]FASTAAdd to basket
« Hide
        10         20         30         40         50
MDFSRRSFHR SLSSSSQGPA LSTSGSLYRK GTMQRLGLHS VYGGWRHGTR
60 70 80 90 100
ISVSKTTMSY GNHLSNGGDL FGGNEKLAMQ NLNDRLASYL EKVRSLEQSN
110 120 130 140 150
SKLEAQIKQW YETNAPSTIR DYSSYYAQIK ELQDQIKDAQ IENARCVLQI
160 170 180 190 200
DNAKLAAEDF RLKFETERGM RITVEADLQG LSKVYDDLTL QKTDLEIQIE
210 220 230 240 250
ELNKDLALLK KEHQEEVEVL RRQLGNNVNV EVDAAPGLNL GEIMNEMRQK
260 270 280 290 300
YEILAQKNLQ EAKEQFERQT QTLEKQVTVN IEELRGTEVQ VTELRRSYQT
310 320 330 340 350
LEIELQSQLS MKESLERTLE ETKARYASQL AAIQEMLSSL EAQLMQIRSD
360 370 380 390 400
TERQNQEYNI LLDIKTRLEQ EIATYRRLLE GEDIKTTEYQ LNTLEAKDIK
410 420
KTRKIKTVVE EVVDGKVVSS EVKEIEENI
Length:429
Mass (Da):49,388
Last modified:September 19, 2002 - v2
<p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.</p> <p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.</p> <p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).</p> <p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x<sup>64</sup> + x<sup>4</sup> + x<sup>3</sup> + x + 1. The algorithm is described in the ISO 3309 standard. </p> <p class="publication">Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.<br /> <strong>Cyclic redundancy and other checksums</strong><br /> <a href="http://www.nrbook.com/b/bookcpdf.php">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993)</a>)</p> Checksum:i95CCA2ABB0F0028C
GO

<p>In eukaryotic reference proteomes, unreviewed entries that are likely to belong to the same gene are computationally mapped, based on gene identifiers from Ensembl, EnsemblGenomes and model organism databases.<p><a href='/help/gene_centric_isoform_mapping' target='_top'>More...</a></p>Computationally mapped potential isoform sequencesi

There are 3 potential isoforms mapped to this entry.BLASTAlignShow allAdd to basket
EntryEntry nameProtein names
Gene namesLengthAnnotation
D3Z7Y6D3Z7Y6_RAT
Keratin, type I cytoskeletal 20
Krt20
431Annotation score:

Annotation score:2 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the 'correct annotation' for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
A0A0G2JTR0A0A0G2JTR0_RAT
Keratin, type I cytoskeletal 20
Krt20
164Annotation score:

Annotation score:1 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the 'correct annotation' for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>
A0A0G2K623A0A0G2K623_RAT
Keratin, type I cytoskeletal 20
Krt20
214Annotation score:

Annotation score:1 out of 5

<p>The annotation score provides a heuristic measure of the annotation content of a UniProtKB entry or proteome. This score <strong>cannot</strong> be used as a measure of the accuracy of the annotation as we cannot define the 'correct annotation' for any given protein.<p><a href='/help/annotation_score' target='_top'>More...</a></p>

Sequence databases

Select the link destinations:

EMBL nucleotide sequence database

More...
EMBLi

GenBank nucleotide sequence database

More...
GenBanki

DNA Data Bank of Japan; a nucleotide sequence database

More...
DDBJi
Links Updated
M63665 mRNA Translation: AAA41473.1

Protein sequence database of the Protein Information Resource

More...
PIRi
A40452

NCBI Reference Sequences

More...
RefSeqi
NP_775151.1, NM_173128.1

Genome annotation databases

Database of genes from NCBI RefSeq genomes

More...
GeneIDi
286912

KEGG: Kyoto Encyclopedia of Genes and Genomes

More...
KEGGi
rno:286912

UCSC genome browser

More...
UCSCi
RGD:628646, rat

<p>This section provides links to proteins that are similar to the protein sequence(s) described in this entry at different levels of sequence identity thresholds (100%, 90% and 50%) based on their membership in UniProt Reference Clusters (<a href="http://www.uniprot.org/help/uniref">UniRef</a>).<p><a href='/help/similar_proteins_section' target='_top'>More...</a></p>Similar proteinsi

<p>This section is used to point to information related to entries and found in data collections other than UniProtKB.<p><a href='/help/cross_references_section' target='_top'>More...</a></p>Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M63665 mRNA Translation: AAA41473.1
PIRiA40452
RefSeqiNP_775151.1, NM_173128.1

3D structure databases

SMRiP25030
ModBaseiSearch...

Protein-protein interaction databases

IntActiP25030, 3 interactors

PTM databases

iPTMnetiP25030
PhosphoSitePlusiP25030

Proteomic databases

jPOSTiP25030
PRIDEiP25030

Genome annotation databases

GeneIDi286912
KEGGirno:286912
UCSCiRGD:628646, rat

Organism-specific databases

Comparative Toxicogenomics Database

More...
CTDi
54474
RGDi628646, Krt20

Phylogenomic databases

InParanoidiP25030
OMAiYSAYYKQ
OrthoDBi798081at2759
PhylomeDBiP25030

Enzyme and pathway databases

ReactomeiR-RNO-6805567, Keratinization
R-RNO-6809371, Formation of the cornified envelope

Miscellaneous databases

Protein Ontology

More...
PROi
PR:P25030

Family and domain databases

Gene3Di1.20.5.1160, 1 hit
InterProiView protein in InterPro
IPR018039, IF_conserved
IPR039008, IF_rod_dom
IPR042180, IF_rod_dom_coil1B
IPR002957, Keratin_I
PANTHERiPTHR23239, PTHR23239, 1 hit
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

MobiDB: a database of protein disorder and mobility annotations

More...
MobiDBi
Search...

<p>This section provides general information on the entry.<p><a href='/help/entry_information_section' target='_top'>More...</a></p>Entry informationi

<p>This subsection of the 'Entry information' section provides a mnemonic identifier for a UniProtKB entry, but it is not a stable identifier. Each reviewed entry is assigned a unique entry name upon integration into UniProtKB/Swiss-Prot.<p><a href='/help/entry_name' target='_top'>More...</a></p>Entry nameiK1C20_RAT
<p>This subsection of the 'Entry information' section provides one or more accession number(s). These are stable identifiers and should be used to cite UniProtKB entries. Upon integration into UniProtKB, each entry is assigned a unique accession number, which is called 'Primary (citable) accession number'.<p><a href='/help/accession_numbers' target='_top'>More...</a></p>AccessioniPrimary (citable) accession number: P25030
<p>This subsection of the 'Entry information' section shows the date of integration of the entry into UniProtKB, the date of the last sequence update and the date of the last annotation modification ('Last modified'). The version number for both the entry and the <a href="http://www.uniprot.org/help/canonical%5Fand%5Fisoforms">canonical sequence</a> are also displayed.<p><a href='/help/entry_history' target='_top'>More...</a></p>Entry historyiIntegrated into UniProtKB/Swiss-Prot: May 1, 1992
Last sequence update: September 19, 2002
Last modified: June 2, 2021
This is version 108 of the entry and version 2 of the sequence. See complete history.
<p>This subsection of the 'Entry information' section indicates whether the entry has been manually annotated and reviewed by UniProtKB curators or not, in other words, if the entry belongs to the Swiss-Prot section of UniProtKB (<strong>reviewed</strong>) or to the computer-annotated TrEMBL section (<strong>unreviewed</strong>).<p><a href='/help/entry_status' target='_top'>More...</a></p>Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programChordata Protein Annotation Program

<p>This section contains any relevant information that doesn't fit in any other defined sections<p><a href='/help/miscellaneous_section' target='_top'>More...</a></p>Miscellaneousi

Keywords - Technical termi

Reference proteome

Documents

  1. SIMILARITY comments
    Index of protein domains and families
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