Keratin 18

KRT18

Identifiers

Aliases

KRT18, CK-18, CYK18, K18, keratin 18

External IDs

OMIM: 148070; MGI: 96692; HomoloGene: 55448; GeneCards: KRT18; OMA:KRT18 - orthologs

Gene location (Human)

Chr.	Chromosome 12 (human)^[1]

Band	12q13.13	Start	52,948,871 bp^[1]
Band	12q13.13	End	52,952,906 bp^[1]

Gene location (Mouse)

Chr.	Chromosome 15 (mouse)^[2]

Band	15 F2\|15 57.22 cM	Start	101,936,615 bp^[2]
Band	15 F2\|15 57.22 cM	End	101,940,462 bp^[2]

RNA expression pattern

Bgee

Human

Mouse (ortholog)

Top expressed in

rectum

body of pancreas

parotid gland

placenta

islet of Langerhans

right uterine tube

duodenum

gallbladder

left lobe of thyroid gland

amniotic fluid

Top expressed in

epithelium of stomach

lacrimal gland

mucous cell of stomach

submandibular gland

seminal vesicula

crypt of lieberkuhn of small intestine

pyloric antrum

parotid gland

left colon

olfactory epithelium

More reference expression data

BioGPS


More reference expression data

Gene ontology
Molecular function	scaffold protein binding structural molecule activity protein binding cadherin binding involved in cell-cell adhesion RNA binding
Cellular component	cytoplasm centriolar satellite keratin filament microtubule organizing center nucleolus perinuclear region of cytoplasm extracellular exosome intermediate filament cell periphery nucleus cytosol
Biological process	Golgi to plasma membrane CFTR protein transport extrinsic apoptotic signaling pathway anatomical structure morphogenesis negative regulation of apoptotic process tumor necrosis factor-mediated signaling pathway intermediate filament cytoskeleton organization cell cycle viral process hepatocyte apoptotic process cell-cell adhesion keratinization cornification
Sources:Amigo / QuickGO

Orthologs

Species

Human

Mouse

Entrez


3875


16668

Ensembl


ENSG00000111057


ENSMUSG00000023043

UniProt


P05783


P05784

RefSeq (mRNA)


NM_199187 NM_000224


NM_010664

RefSeq (protein)


NP_000215 NP_954657


NP_034794

Location (UCSC)

Chr 12: 52.95 – 52.95 Mb

Chr 15: 101.94 – 101.94 Mb

PubMed search

^[3]

^[4]

Wikidata

View/Edit Human

View/Edit Mouse

Keratin 18 is a type I cytokeratin. It is, together with its filament partner keratin 8, perhaps the most commonly found products of the intermediate filament gene family. They are expressed in single layer epithelial tissues of the body. Mutations in this gene have been linked to cryptogenic cirrhosis. Two transcript variants encoding the same protein have been found for this gene.^[5]

Keratin 18 is often used together with keratin 8 and keratin 19 to differentiate cells of epithelial origin from hematopoietic cells in tests that enumerate circulating tumor cells in blood.^[6]

Interactions

Keratin 18 has been shown to interact with Collagen, type XVII, alpha 1,^[7] DNAJB6,^[8] Pinin^[9] and TRADD.^[10]

References

^ ^a ^b ^c GRCh38: Ensembl release 89: ENSG00000111057 – Ensembl, May 2017
^ ^a ^b ^c GRCm38: Ensembl release 89: ENSMUSG00000023043 – Ensembl, May 2017
^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^ "Entrez Gene: KRT18 keratin 18".
^ W. Jeffrey Allard, Jeri Matera, M. Craig Miller, et al. (October 2004). "Tumor Cells Circulate in the Peripheral Blood of All Major Carcinomas but not in Healthy Subjects or Patients With Nonmalignant Diseases" (PDF). Clinical Cancer Research. 10 (20): 6897–6904. doi:10.1158/1078-0432.CCR-04-0378. PMID 15501967.
^ Aho S, Uitto J (March 1999). "180-kD bullous pemphigoid antigen/type XVII collagen: tissue-specific expression and molecular interactions with keratin 18". J. Cell. Biochem. 72 (3): 356–67. doi:10.1002/(SICI)1097-4644(19990301)72:3<356::AID-JCB5>3.0.CO;2-M. ISSN 0730-2312. PMID 10022517. S2CID 30404639.
^ Izawa I, Nishizawa M, Ohtakara K, Ohtsuka K, Inada H, Inagaki M (November 2000). "Identification of Mrj, a DnaJ/Hsp40 family protein, as a keratin 8/18 filament regulatory protein". J. Biol. Chem. 275 (44): 34521–7. doi:10.1074/jbc.M003492200. ISSN 0021-9258. PMID 10954706.
^ Shi J, Sugrue S P (May 2000). "Dissection of protein linkage between keratins and pinin, a protein with dual location at desmosome-intermediate filament complex and in the nucleus". J. Biol. Chem. 275 (20): 14910–5. doi:10.1074/jbc.275.20.14910. ISSN 0021-9258. PMID 10809736.
^ Inada H, Izawa I, Nishizawa M, Fujita E, Kiyono T, Takahashi T, Momoi T, Inagaki M (October 2001). "Keratin attenuates tumor necrosis factor-induced cytotoxicity through association with TRADD". J. Cell Biol. 155 (3): 415–26. doi:10.1083/jcb.200103078. ISSN 0021-9525. PMC 2150850. PMID 11684708.

Omary MB, Baxter GT, Chou CF, et al. (1992). "PKC epsilon-related kinase associates with and phosphorylates cytokeratin 8 and 18". J. Cell Biol. 117 (3): 583–93. doi:10.1083/jcb.117.3.583. PMC 2289443. PMID 1374067.
Waseem A, Gough AC, Spurr NK, Lane EB (1990). "Localization of the gene for human simple epithelial keratin 18 to chromosome 12 using polymerase chain reaction". Genomics. 7 (2): 188–94. doi:10.1016/0888-7543(90)90540-B. PMID 1693358.
Heath P, Elvin P, Jenner D, et al. (1990). "Localisation of a cDNA clone for human cytokeratin 18 to chromosome 17p11-p12 by in situ hybridisation". Hum. Genet. 85 (6): 669–70. doi:10.1007/BF00193596. PMID 1699878. S2CID 19296094.
Waseem A, Alexander CM, Steel JB, Lane EB (1991). "Embryonic simple epithelial keratins 8 and 18: chromosomal location emphasizes difference from other keratin pairs". New Biol. 2 (5): 464–78. PMID 1705144.
Romano V, Hatzfeld M, Magin TM, et al. (1986). "Cytokeratin expression in simple epithelia. I. Identification of mRNA coding for human cytokeratin no. 18 by a cDNA clone". Differentiation. 30 (3): 244–53. doi:10.1111/j.1432-0436.1986.tb00787.x. PMID 2422083.
Oshima RG, Millán JL, Ceceña G (1987). "Comparison of mouse and human keratin 18: a component of intermediate filaments expressed prior to implantation". Differentiation. 33 (1): 61–8. doi:10.1111/j.1432-0436.1987.tb01542.x. PMID 2434380.
Leube RE, Bosch FX, Romano V, et al. (1987). "Cytokeratin expression in simple epithelia. III. Detection of mRNAs encoding human cytokeratins nos. 8 and 18 in normal and tumor cells by hybridization with cDNA sequences in vitro and in situ". Differentiation. 33 (1): 69–85. doi:10.1111/j.1432-0436.1986.tb00412.x. PMID 2434381.
Kulesh DA, Oshima RG (1988). "Cloning of the human keratin 18 gene and its expression in nonepithelial mouse cells". Mol. Cell. Biol. 8 (4): 1540–50. doi:10.1128/MCB.8.4.1540. PMC 363314. PMID 2454392.
Sémat A, Vasseur M, Maillet L, et al. (1988). "Sequence analysis of murine cytokeratin endo A (no. 8) cDNA. Evidence for mRNA species initiated upstream of the normal 5' end in PCC4 cells". Differentiation. 37 (1): 40–6. doi:10.1111/j.1432-0436.1988.tb00794.x. PMID 2454862.
Kulesh DA, Oshima RG (1989). "Complete structure of the gene for human keratin 18". Genomics. 4 (3): 339–47. doi:10.1016/0888-7543(89)90340-6. PMID 2469635.
Ku NO, Omary MB (1994). "Identification of the major physiologic phosphorylation site of human keratin 18: potential kinases and a role in filament reorganization". J. Cell Biol. 127 (1): 161–71. doi:10.1083/jcb.127.1.161. PMC 2120194. PMID 7523419.
Liao J, Lowthert LA, Ghori N, Omary MB (1995). "The 70-kDa heat shock proteins associate with glandular intermediate filaments in an ATP-dependent manner". J. Biol. Chem. 270 (2): 915–22. doi:10.1074/jbc.270.2.915. PMID 7529764.
Yoon SJ, LeBlanc-Straceski J, Ward D, et al. (1995). "Organization of the human keratin type II gene cluster at 12q13". Genomics. 24 (3): 502–8. doi:10.1006/geno.1994.1659. PMID 7536183.
Ku NO, Omary MB (1995). "Identification and mutational analysis of the glycosylation sites of human keratin 18". J. Biol. Chem. 270 (20): 11820–7. doi:10.1074/jbc.270.20.11820. PMID 7538124.
Neumaier M, Gerhard M, Wagener C (1995). "Diagnosis of micrometastases by the amplification of tissue-specific genes". Gene. 159 (1): 43–7. doi:10.1016/0378-1119(94)00522-T. PMID 7541767.
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.
Liao J, Lowthert LA, Ku NO, et al. (1996). "Dynamics of human keratin 18 phosphorylation: polarized distribution of phosphorylated keratins in simple epithelial tissues". J. Cell Biol. 131 (5): 1291–301. doi:10.1083/jcb.131.5.1291. PMC 2120635. PMID 8522590.
Ku NO, Wright TL, Terrault NA, et al. (1997). "Mutation of human keratin 18 in association with cryptogenic cirrhosis". J. Clin. Invest. 99 (1): 19–23. doi:10.1172/JCI119127. PMC 507762. PMID 9011570.
Ji H, Reid GE, Moritz RL, et al. (1997). "A two-dimensional gel database of human colon carcinoma proteins". Electrophoresis. 18 (3–4): 605–13. doi:10.1002/elps.1150180344. PMID 9150948. S2CID 25454450.

Proteins of the cytoskeleton

Human

Microfilaments
and 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

Intermediate
filaments

Type 1/2
(Keratin,
Cytokeratin)

Epithelial keratins (soft alpha-keratins)	type I/chromosome 17 9 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 6C 7 8
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

Type 4

Type 5

Microtubules
and MAPs

Tubulins	TUBA1A TUBA1B TUBA1C TUBA3C TUBA3D TUBA3E TUBA4A TUBA8 TUBB TUBB1 TUBB2A TUBB2B TUBB2C TUBB3 TUBB4 TUBB4Q TUBB6 TUBB8 TUBG1 TUBG2 TUBGCP2 TUBGCP3 TUBGCP4 TUBGCP5 TUBGCP6 TUBD1 TUBE1
MAPs	EB1 EB2 EB3 MAP1A MAP1B MAP2 MAP4
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
Microtubule organising proteins	CAMSAP1 CAMSAP2 CAMSAP3 Centrin 1 Centrin 2 Centrin 3 PCM1
Microtubule severing proteins	Katanin Spastin
Other	Tau protein Dynactin DCTN1 Stathmin Tektin TEKT1 TEKT2 TEKT3 TEKT4 TEKT5 Dynamin DNM1 DNM2 DNM3