Keratin 7

Keratin 7, type II
Identifiers
Symbols	KRT7 ; CK7; K2C7; K7; SCL
External IDs	OMIM: 148059 MGI: 96704 HomoloGene: 4058 GeneCards: KRT7 Gene
Gene ontology Molecular function • structural molecule activity • protein binding Cellular component • nucleus • cytoplasm • intermediate filament • keratin filament • extracellular exosome Biological process • viral process Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	3855	110310
Ensembl	ENSG00000135480	ENSMUSG00000023039
UniProt	P08729	Q9DCV7
RefSeq (mRNA)	NM_005556	NM_033073
RefSeq (protein)	NP_005547	NP_149064
Location (UCSC)	Chr 12: 52.23 – 52.25 Mb	Chr 15: 101.41 – 101.43 Mb
PubMed search	[1]	[2]

Keratin, type II cytoskeletal 7 also known as cytokeratin-7 (CK-7) or keratin-7 (K7) or sarcolectin (SCL) is a protein that in humans is encoded by the KRT7 gene. Keratin 7 is a type II keratin. It is specifically expressed in the simple epithelia lining the cavities of the internal organs and in the gland ducts and blood vessels.

Function

Keratin-7 is a member of the keratin gene family. The type II cytokeratins consist of basic or neutral proteins which are arranged in pairs of heterotypic keratin chains coexpressed during differentiation of simple and stratified epithelial tissues. This type II cytokeratin is specifically expressed in the simple epithelia lining the cavities of the internal organs and in the gland ducts and blood vessels. The genes encoding the type II cytokeratins are clustered in a region of chromosome 12q12-q13. Alternative splicing may result in several transcript variants; however, not all variants have been fully described.

Keratin-7 is found in simple glandular epithelia, and in transitional epithelium. Epithelial cells of the lung and breast both contain keratin-7, but some other glandular epithelia, such as those of the colon and prostate, do not. Because the keratin-7 antigen is found in both healthy and neoplastic cells, antibodies to CK7 can be used in immunohistochemistry to distinguish ovarian and transitional cell carcinomas from colonic and prostate cancers, respectively. It is commonly used together with CK20 when making such diagnoses.

Model organisms

Model organisms have been used in the study of KRT7 function. A conditional knockout mouse line called Krt7^{tm1b(KOMP)Wtsi} was generated at the Wellcome Trust Sanger Institute. Male and female animals underwent a standardized phenotypic screen to determine the effects of deletion. Additional screens performed: - In-depth immunological phenotyping

Krt7 knockout mouse phenotype

Characteristic	Phenotype
All data available at.
Insulin	Normal
Homozygous viability at P14	Normal
Homozygous Fertility	Normal
Body weight	Normal
Neurological assessment	Normal
Grip strength	Normal
Dysmorphology	Normal
Indirect calorimetry	Normal
Glucose tolerance test	Normal
Auditory brainstem response	Normal
DEXA	Normal
Radiography	Normal
Eye morphology	Normal
Clinical chemistry	Normal
Haematology 16 Weeks	Normal
Peripheral blood leukocytes 16 Weeks	Normal
Heart weight	Normal
Salmonella infection	Normal
Spleen Immunophenotyping	Normal
Mesenteric Lymph Node Immunophenotyping	Normal
Epidermal Immune Composition	Normal
Influenza Challenge	Normal