Keratin 7

Identifiers

KRT7; CK7; K2C7; K7; MGC129731; MGC3625; SCL

External IDs

OMIM: 148059 MGI: 96704 HomoloGene: 4058 GeneCards: KRT7 Gene

Gene Ontology
Molecular function	• structural molecule activity • protein binding
Cellular component	• nucleus • nucleolus • cytoplasm • Golgi apparatus • intermediate filament • keratin filament
Biological process	• DNA replication • regulation of translation • cytoskeleton organization • interspecies interaction between organisms • interphase
Sources: Amigo / QuickGO

RNA expression pattern

More reference expression data

Orthologs

Species

Human

Mouse

n/a

RefSeq (mRNA)

RefSeq (protein)

Location (UCSC)

Chr 12:
52.63 – 52.66 Mb

Chr 15:
101.24 – 101.26 Mb

PubMed search

[1]

[2]

Keratin, type I 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.^[1]^[2]^[3] 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.^[3]

References

^ Rosenberg M, Fuchs E, Le Beau MM, Eddy RL, Shows TB (Aug 1991). "Three epidermal and one simple epithelial type II keratin genes map to human chromosome 12". Cytogenet Cell Genet 57 (1): 33–8. doi:10.1159/000133109. PMID 1713141.
^ Schweizer J, Bowden PE, Coulombe PA, Langbein L, Lane EB, Magin TM, Maltais L, Omary MB, Parry DA, Rogers MA, Wright MW (Jul 2006). "New consensus nomenclature for mammalian keratins". J Cell Biol 174 (2): 169–74. doi:10.1083/jcb.200603161. PMC 2064177. PMID 16831889. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2064177.
^ ^a ^b "Entrez Gene: KRT7 keratin 7". http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=3855.

Bouwens L (1998). "Cytokeratins and cell differentiation in the pancreas". J. Pathol. 184 (3): 234–9. doi:10.1002/(SICI)1096-9896(199803)184:3<234::AID-PATH28>3.0.CO;2-D. PMID 9614373.
Glass C, Kim KH, Fuchs E (1986). "Sequence and expression of a human type II mesothelial keratin". J. Cell Biol. 101 (6): 2366–73. doi:10.1083/jcb.101.6.2366. PMC 2114014. PMID 2415537. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2114014.
Ramaekers F, Huysmans A, Schaart G, et al. (1987). "Tissue distribution of keratin 7 as monitored by a monoclonal antibody". Exp. Cell Res. 170 (1): 235–49. doi:10.1016/0014-4827(87)90133-9. PMID 2436934.
Glass C, Fuchs E (1988). "Isolation, sequence, and differential expression of a human K7 gene in simple epithelial cells". J. Cell Biol. 107 (4): 1337–50. doi:10.1083/jcb.107.4.1337. PMC 2115265. PMID 2459129. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2115265.
Maruyama K, Sugano S (1994). "Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides". Gene 138 (1-2): 171–4. doi:10.1016/0378-1119(94)90802-8. PMID 8125298.
Gress TM, Müller-Pillasch F, Geng M, et al. (1996). "A pancreatic cancer-specific expression profile". Oncogene 13 (8): 1819–30. PMID 8895530.
Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, et al. (1997). "Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library". Gene 200 (1-2): 149–56. doi:10.1016/S0378-1119(97)00411-3. PMID 9373149.
Alvarez Alvarez C, Sánchez Merino JM, Busto Castañón L, et al. (1998). "[Mucinous adenocarcinoma of the urachus synchronic with colorectal adenocarcinoma. Value of immunohistochemistry in the differential diagnosis]". Actas urologicas españolas 22 (6): 515–8. PMID 9734130.
Kaba A, Jiang PH, Chany-Fournier F, Chany C (1999). "Sarcolectin (SCL): structure and expression of the recombinant molecule". Biochimie 81 (7): 709–15. doi:10.1016/S0300-9084(99)80128-X. PMID 10492017.
Lin L, Holbro T, Alonso G, et al. (2001). "Molecular interaction between human tumor marker protein p150, the largest subunit of eIF3, and intermediate filament protein K7". J. Cell. Biochem. 80 (4): 483–90. doi:10.1002/1097-4644(20010315)80:4<483::AID-JCB1002>3.0.CO;2-B. PMID 11169732.
Suzuki H, Fukunishi Y, Kagawa I, et al. (2001). "Protein-protein interaction panel using mouse full-length cDNAs". Genome Res. 11 (10): 1758–65. doi:10.1101/gr.180101. PMC 311163. PMID 11591653. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=311163.
Harris RA, Yang A, Stein RC, et al. (2002). "Cluster analysis of an extensive human breast cancer cell line protein expression map database". Proteomics 2 (2): 212–23. doi:10.1002/1615-9861(200202)2:2<212::AID-PROT212>3.0.CO;2-H. PMID 11840567.
Bonvini P, Gastaldi T, Falini B, Rosolen A (2002). "Nucleophosmin-anaplastic lymphoma kinase (NPM-ALK), a novel Hsp90-client tyrosine kinase: down-regulation of NPM-ALK expression and tyrosine phosphorylation in ALK(+) CD30(+) lymphoma cells by the Hsp90 antagonist 17-allylamino,17-demethoxygeldanamycin". Cancer Res. 62 (5): 1559–66. PMID 11888936.
Jovanovic I, Tzardi M, Mouzas IA, et al. (2002). "Changing pattern of cytokeratin 7 and 20 expression from normal epithelium to intestinal metaplasia of the gastric mucosa and gastroesophageal junction". Histol. Histopathol. 17 (2): 445–54. PMID 11962749.
Kanduc D (2002). "Translational regulation of human papillomavirus type 16 E7 mRNA by the peptide SEQIKA, shared by rabbit alpha(1)-globin and human cytokeratin 7". J. Virol. 76 (14): 7040–8. doi:10.1128/JVI.76.14.7040-7048.2002. PMC 136328. PMID 12072504. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=136328.
Smith FJ, Porter RM, Corden LD, et al. (2002). "Cloning of human, murine, and marsupial keratin 7 and a survey of K7 expression in the mouse". Biochem. Biophys. Res. Commun. 297 (4): 818–27. doi:10.1016/S0006-291X(02)02288-X. PMID 12359226.
Strausberg RL, Feingold EA, Grouse LH, et al. (2003). "Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences". Proc. Natl. Acad. Sci. U.S.A. 99 (26): 16899–903. doi:10.1073/pnas.242603899. PMC 139241. PMID 12477932. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=139241.
Blagoev B, Kratchmarova I, Ong SE, et al. (2003). "A proteomics strategy to elucidate functional protein-protein interactions applied to EGF signaling". Nat. Biotechnol. 21 (3): 315–8. doi:10.1038/nbt790. PMID 12577067.

Proteins of the cytoskeleton

Human

Microfilaments
(ABPs)

Myofilament

Actins	A1, A2, B, C1, G1, G2

Myosins	I (MYO1A, MYO1B, MYO1C, MYO1D, MYO1E, MYO1F, MYO1G, MYO1H) · II (MYH1, MYH2, MYH3, MYH4, MYH6, MYH7, MYH7B, MYH8, MYH9, MYH10, MYH11, MYH13, MYH14, MYH15, MYH16) · III (MYO3A, MYO3B) · V (MYO5A, MYO5B, MYO5C) · VI (MYO6) · VII (MYO7A, MYO7B) · IX (MYO9A, MYO9B) · X (MYO10) · XV (MYO15A) · XVIII (MYO18A, MYO18B) · LC (MYL1, MYL2, MYL3, MYL4, MYL5, MYL6, MYL6B, MYL7, MYL9, MYLIP, MYLK, MYLK2, MYLL1)

Other	Tropomodulin (1, 2, 3, 4) · Troponin (T 1 2 3, C 1 2, I 1 2 3) · Tropomyosin (1, 2, 3, 4) Actinin (1, 2, 3, 4) · Arp2/3 complex · actin depolymerizing factors (Cofilin (1, 2) · Destrin) · Gelsolin · Profilin (1, 2) · Titin

Other

Wiskott-Aldrich syndrome protein · Fibrillin · Filamin (FLNA, FLNB, FLNC) · Espin · TRIOBP

IFs

Type 1/2
(Keratin,
Cytokeratin)

Epithelial keratins (soft alpha-keratins)	type I/chromosome 17 (10, 12, 13, 14, 15, 16, 17, 19, 20) · chromosome 12 (18) · none (21) type II/chromosome 12 (1, 2A, 3, 4, 5, 6A, 6B, 7, 8, 9)

Hair keratins (hard alpha-keratins)	type I/chromosome 17 (31, 32, 33A, 33B, 34, 35, 36, 37, 38) type II/chromosome 12 (81, 82, 83, 84, 85, 86)

Ungrouped alpha	chromosome 17 (23, 24, 25, 26, 27, 28, 39, 40) chromosome 12 (71, 72, 73, 74, 75, 76, 77, 78, 79, 80)

Not alpha	Beta-keratin

Type 3

Desmin, GFAP, Peripherin, Vimentin

Type 4

Internexin, Nestin, Neurofilament (NEFL, NEFM, NEFH), Synemin, Syncoilin

Type 5

Lamin A, B

Microtubules/
MAPs

Kinesins	KIF1A, KIF1B, KIF2A, KIF2C, KIF3B, KIF3C, KIF4A, KIF4B, KIF5A, KIF5B, KIF5C, KIF6, KIF7, KIF9, KIF11, KIF12, KIF13A, KIF13B, KIF14, KIF15, KIF16B, KIF17, KIF18A, KIF18B, KIF19, KIF20A, KIF20B, KIF21A, KIF21B, KIF22, KIF23, KIF24, KIF25, KIF26A, KIF26B, KIF27, KIFC1, KIFC2, KIFC3

Dyneins	axonemal: DNAH1, DNAH2, DNAH3, DNAH5, DNAH6, DNAH7, DNAH8, DNAH9, DNAH10, DNAH11, DNAH12, DNAH13, DNAH14, DNAH17, DNAI1, DNAI2, DNALI1, DNAL1, DNAL4 cytoplasmic: DYNC1H1, DYNC2H1, DYNC1I1, DYNC1I2, DYNC1LI1, DYNC1LI2, DYNC2LI1, DYNLL1, DYNLL2, DYNLRB1, DYNLRB2, DYNLT1, DYNLT3

Other	Tau protein · Dynactin (DCTN1) · Tubulins (TUBA1A, TUBA1B, TUBA1C, TUBA3C, TUBA3D, TUBA3E, TUBA4A, TUBA8) · Stathmin · Tektin (TEKT1, TEKT2, TEKT3, TEKT4, TEKT5) · Dynamin (DNM1, DNM2, DNM3)

Catenins

Alpha catenin · Beta catenin (APC) · Plakoglobin (gamma catenin) · Delta catenin · GAN

Membrane

Dystrophin (Dystroglycan) · Utrophin · Ankyrin (ANK1, ANK2, ANK3) · Spectrin (SPTA1, SPTAN1, SPTB, SPTBN1, SPTBN2, SPTBN4, SPTBN5)

Other

plakin (Desmoplakin, Plectin) · Talin (TLN1) · Vinculin · Plakophilin (PKP1, PKP2)

Nonhuman

Major sperm proteins · Prokaryotic cytoskeleton (Crescentin, FtsZ, MreB)

see also cytoskeletal defects
B strc: edmb (perx), skel (ctrs), epit, cili, mito, nucl (chro)

Keratin 7

Function

References

Further reading