<p>An evidence describes the source of an annotation, e.g. an experiment that has been published in the scientific literature, an orthologous protein, a record from another database, etc.</p>
<p><a href="/manual/evidences">More...</a></p>
Your basket is currently empty. i
<p>When browsing through different UniProt proteins, you can use the ‘basket’ to save them, so that you can back to find or analyse them later.<p><a href='/help/basket' target='_top'>More...</a></p>
Select item(s) and click on "Add to basket" to create your own collection here (400 entries max)
<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>
Select a section on the left to see content.
<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
May play a unique role in maintaining the normal corneal epithelial function. Together with KRT3, essential for the maintenance of corneal epithelium integrity.2 Publications
<p>Manually curated information for which there is published experimental evidence.</p>
<p><a href="/manual/evidences#ECO:0000269">More...</a></p>
Manual assertion based on experiment ini
cornea development in camera-type eye Source: MGI
<p>Inferred from Mutant Phenotype</p>
<p>Describes annotations that are concluded from looking at variations or changes in a gene product such as mutations or abnormal levels and includes techniques such as knockouts, overexpression, anti-sense experiments and use of specific protein inhibitors.</p>
<p>More information in the <a href="http://geneontology.org/page/guide-go-evidence-codes#imp">GO evidence code guide</a></p>
Inferred from mutant phenotypei
<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_and_taxonomy_section">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 12
Alternative name(s):
Cytokeratin-12
Short name:
CK-12
Keratin-12
Short name:
K12
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">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
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">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>Organismi
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">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 identifieri
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">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 lineagei
<p>This subsection of the <a href="http://www.uniprot.org/help/names_and_taxonomy_section">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
UP000000589
<p>A UniProt <a href="http://www.uniprot.org/manual/proteomes_manual">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
Mouse genome database (MGD) from Mouse Genome Informatics (MGI)
<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
<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>Keywords - Cellular componenti
<p>This subsection of the ‘PTM / Processing’ section describes the extent of a polypeptide chain in the mature protein following processing.<p><a href='/help/chain' target='_top'>More...</a></p>ChainiPRO_0000063645
<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
Cornea specific. Associated mainly with all layers of the central corneal epithelium and also found in the suprabasal limbal epithelium.1 Publication
<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
Expression commences in corneal peridermal epithelium in embryo at 15.5 dpc. Between the 15.5 dpc embryonic stage to 4 day postnatal phase, expression is restricted to the suprabasal and/or superficial cells when the corneal epithelium begins to stratify. At 30 day postnatally, expression is sporadically detected in the basal corneal epithelium and the number of positive basal cells increases as the mice grow older.2 Publications
<p>This subsection of the ‘Expression’ section reports the experimentally proven effects of inducers and repressors (usually chemical compounds or environmental factors) on the level of protein (or mRNA) expression (up-regulation, down-regulation, constitutive expression).<p><a href='/help/induction' target='_top'>More...</a></p>Inductioni
Expression is retarded by epidermal growth factor (EGF).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_section">'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_section">'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. Keratin-3 associates with keratin-12.
<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
Protein Model Portal of the PSI-Nature Structural Biology Knowledgebase
<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 key
Position(s)
DescriptionActions
Graphical view
Length
<p>This subsection of the <a href="http://www.uniprot.org/help/family_and_domains_section">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>Domaini
<p>Manual validated information which has been generated by the UniProtKB automatic annotation system.</p>
<p><a href="/manual/evidences#ECO:0000255">More...</a></p>
Manual assertion according to rulesi
<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>Regioni
<p>This subsection of the ‘Family and Domains’ section describes the position of regions of compositional bias within the protein and the particular amino acids that are over-represented within those regions.<p><a href='/help/compbias' target='_top'>More...</a></p>Compositional biasi
<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
<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_length">length</a> and <a href="http://www.uniprot.org/help/sequences">molecular weight</a>.<p><a href='/help/sequences_section' target='_top'>More...</a></p>Sequences (2+)i
<p>This subsection of the <a href="http://www.uniprot.org/help/sequences_section">Sequence</a> section indicates if the <a href="http://www.uniprot.org/help/canonical_and_isoforms">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 describes 2
<p>This subsection of the ‘Sequence’ section lists the alternative protein sequences (isoforms) that can be generated from the same gene by a single or by the combination of up to four biological events (alternative promoter usage, alternative splicing, alternative initiation and ribosomal frameshifting). Additionally, this section gives relevant information on each alternative protein isoform.<p><a href='/help/alternative_products' target='_top'>More...</a></p> isoformsi produced by alternative splicing. AlignAdd to basketAdded to basket
This entry has 2 described isoforms and 1 potential isoform that is computationally mapped.Show allAlign All
This isoform has been chosen as the 'canonical' sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
<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:i76FA2380822DCB94
<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
<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>
<p>This subsection of the ‘Sequence’ section reports difference(s) between the protein sequence shown in the UniProtKB entry and other available protein sequences derived from the same gene.<p><a href='/help/sequence_caution' target='_top'>More...</a></p>Sequence cautioni
The sequence AAA17792 differs from that shown. Reason: Frameshift at position 481.Curated
The sequence AAA52359 differs from that shown. Reason: Frameshift at position 481.Curated
Experimental Info
Feature key
Position(s)
DescriptionActions
Graphical view
Length
<p>This subsection of the ‘Sequence’ section reports difference(s) between the canonical sequence (displayed by default in the entry) and the different sequence submissions merged in the entry. These various submissions may originate from different sequencing projects, different types of experiments, or different biological samples. Sequence conflicts are usually of unknown origin.<p><a href='/help/conflict' target='_top'>More...</a></p>Sequence conflicti
<p>This subsection of the ‘Sequence’ section describes the sequence of naturally occurring alternative protein isoform(s). The changes in the amino acid sequence may be due to alternative splicing, alternative promoter usage, alternative initiation, or ribosomal frameshifting. The information stored in this subsection is used to automatically construct alternative protein sequence(s) for display.<p><a href='/help/var_seq' target='_top'>More...</a></p>Alternative sequenceiVSP_002463
<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
<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 namei
K1C12_MOUSE
<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>Accessioni
<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_and_isoforms">canonical sequence</a> are also displayed.<p><a href='/help/entry_history' target='_top'>More...</a></p>Entry historyi
Integrated into UniProtKB/Swiss-Prot:
November 1, 1997
Last sequence update:
April 3, 2007
Last modified:
May 23, 2018
This is version 128 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 statusi
<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
We'd like to inform you that we have updated our Privacy Notice to comply
with Europe’s new General Data Protection Regulation (GDPR) that applies since 25 May 2018.
