P05784 (K1C18_MOUSE) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names

Recommended name:
Keratin, type I cytoskeletal 18

Alternative name(s):
Cytokeratin endo B
Short name=Keratin D
Cytokeratin-18
Short name=CK-18
Keratin-18
Short name=K18

Gene names

Name:	Krt18
Synonyms:	Kerd, Krt1-18

Organism

Mus musculus (Mouse) [Reference proteome]

Taxonomic identifier

10090 [NCBI]

Taxonomic lineage

cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Deuterostomia › Chordata › Craniata › Vertebrata › Gnathostomata › Teleostomi › Euteleostomi › Sarcopterygii › Tetrapoda › Amniota › Mammalia › Theria › Eutheria › Euarchontoglires › Glires › Rodentia › Sciurognathi › Muroidea › Muridae › Murinae › Mus › Mus

Protein attributes

Sequence length	423 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	When phosphorylated, plays a role in filament reorganization. Involved in the delivery of mutated CFTR to the plasma membrane. Involved in the uptake of thrombin-antithrombin complexes by hepatic cells By similarity. Together with KRT8, is involved in interleukin-6 (IL-6)-mediated barrier protection. Ref.11
Subunit structure	Heterotetramer of two type I and two type II keratins. KRT18 associates with KRT8. Interacts with PNN, HCV core protein and mutated CFTR. Interacts with YWHAE, YWHAH and YWHAZ only when phosphorylated. Interacts with the thrombin-antithrombin complex. Interacts with DNAJB6, TCHP and TRADD By similarity.
Subcellular location	Nucleus matrix By similarity. Nucleus › nucleolus By similarity. Cytoplasm By similarity.
Tissue specificity	Expressed in endoderm, intestinal epithelial cells and in most extraembryonic tissues. Ref.1 Ref.6 Ref.7 Ref.11
Developmental stage	During embryogenesis, expressed in a complex spatial and temporal pattern in various embryonic epithelia. In 7.5 and 13.5 day old embryo, expressed in most endodermal epithelia, ectodermal and nascent mesodermal tissues. When the neural plate forms, expression begins in the cells of skin ectoderm, head process/notochord, periderm, whisker buds, choroid plexus and the epithelia of auditory duct and inner ear. High expression in the lining endodermal cells when the foregut and hindgut invaginations form. Expression in all three layers of the urothelium starts at day 15 in the embryo and is not visible after day 18. By day 11 and 12, the entire embryonic palatal epithelium shows expression as well as the nasal passages and the roof of the mouth; which disappears progresively from day 13 to 15. Ref.7 Ref.8 Ref.10
Induction	By retinoic acid and IL-6. Ref.1 Ref.11
Post-translational modification	Phosphorylation increases by IL-6. Proteolytically cleaved by caspases during epithelial cell apoptosis. Cleavage occurs at Asp-231 by either caspase-3, caspas-6 or caspase-7. Ref.9 O-GlcNAcylation increases solubility, and decreases stability by inducing proteasomal degradation 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).
Sequence similarities	Belongs to the intermediate filament family.

Ontologies

Keywords
Cellular component	Cytoplasm Intermediate filament Keratin Nucleus
Domain	Coiled coil
PTM	Acetylation Glycoprotein Phosphoprotein
Technical term	Complete proteome Reference proteome
Gene Ontology (GO)
Biological_process	Golgi to plasma membrane CFTR protein transport Inferred from electronic annotation. Source: Compara apoptotic process Inferred from mutant phenotype PubMed 10747083. Source: MGI negative regulation of apoptotic process Inferred from electronic annotation. Source: Compara tumor necrosis factor-mediated signaling pathway Inferred from genetic interaction PubMed 10747083. Source: MGI
Cellular_component	centriolar satellite Inferred from electronic annotation. Source: Compara keratin filament Inferred from direct assay PubMed 21930775. Source: MGI nuclear matrix Inferred from electronic annotation. Source: UniProtKB-SubCell nucleolus Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular_function	structural molecule activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Initiator methionine	1	1	Removed By similarity
	Chain	2 – 423	422	Keratin, type I cytoskeletal 18		PRO_0000063667
Regions
	Region	2 – 71	70	Head
	Region	62 – 366	305	Necessary for interaction with PNN By similarity
	Region	69 – 121	53	Interaction with TRADD By similarity
	Region	72 – 380	309	Rod
	Region	72 – 107	36	Coil 1A
	Region	108 – 125	18	Linker 1
	Region	126 – 217	92	Coil 1B
	Region	218 – 241	24	Linker 12
	Region	236 – 384	149	Interaction with DNAJB6 By similarity
	Region	242 – 380	139	Coil 2
	Region	381 – 423	43	Tail
Sites
	Site	231 – 232	2	Cleavage; by caspase-3, caspase-6 or caspase-7
	Site	264	1	Stutter
	Site	324	1	Stutter
Amino acid modifications
	Modified residue	2	1	N-acetylserine By similarity
	Modified residue	7	1	Phosphoserine By similarity
	Modified residue	8	1	Phosphothreonine Ref.13
	Modified residue	9	1	Phosphothreonine By similarity
	Modified residue	11	1	Phosphoserine By similarity
	Modified residue	12	1	Phosphothreonine Ref.13
	Modified residue	16	1	Phosphoserine By similarity
	Modified residue	19	1	Phosphoserine By similarity
	Modified residue	31	1	Phosphoserine; alternate Ref.13
	Modified residue	32	1	Phosphoserine; alternate Ref.13
	Modified residue	35	1	Phosphoserine Ref.13
	Modified residue	37	1	Phosphotyrosine By similarity
	Modified residue	43	1	Phosphoserine By similarity
	Modified residue	52	1	Phosphoserine; by MAPKAPK2 and MAPKAPK3 Ref.14
	Modified residue	60	1	Phosphoserine By similarity
	Modified residue	92	1	Phosphoserine By similarity
	Modified residue	124	1	N6-acetyllysine By similarity
	Modified residue	170	1	Phosphoserine By similarity
	Modified residue	295	1	Phosphothreonine By similarity
	Modified residue	392	1	Phosphoserine By similarity
	Modified residue	394	1	Phosphoserine Ref.12
	Modified residue	397	1	Phosphothreonine Ref.12
	Glycosylation	31	1	O-linked (GlcNAc); alternate By similarity
	Glycosylation	32	1	O-linked (GlcNAc); alternate By similarity
	Glycosylation	50	1	O-linked (GlcNAc) By similarity
Experimental info
	Sequence conflict	134	1	F → L in AAA39390. Ref.1
	Sequence conflict	134	1	F → L in AAA39373. Ref.2
	Sequence conflict	214	1	V → A in BAE26424. Ref.4
	Sequence conflict	214	1	V → A in BAE39378. Ref.4
	Sequence conflict	244	1	D → N in AAA39373. Ref.2
	Sequence conflict	253	1	A → G in AAA39373. Ref.2
	Sequence conflict	300	1	E → G in BAE39725. Ref.4

Sequences

	Sequence		Length	Mass (Da)
	P05784 [UniParc]. Last modified May 29, 2007. Version 5. Checksum: A67ACD6814A02118	FASTA	423	47,538
	10 20 30 40 50 60 MSFTTRSTTF STNYRSLGSV RTPSQRVRPA SSAASVYAGA GGSGSRISVS RSVWGGSVGS 70 80 90 100 110 120 AGLAGMGGIQ TEKETMQDLN DRLASYLDKV KSLETENRRL ESKIREHLEK KGPQGVRDWG 130 140 150 160 170 180 HYFKIIEDLR AQIFANSVDN ARIVLQIDNA RLAADDFRVK YETELAMRQS VESDIHGLRK 190 200 210 220 230 240 VVDDTNITRL QLETEIEALK EELLFMKKNH EEEVQGLEAQ IASSGLTVEV DAPKSQDLSK 250 260 270 280 290 300 IMADIRAQYE ALAQKNREEL DKYWSQQIEE STTVVTTKSA EIRDAETTLT ELRRTLQTLE 310 320 330 340 350 360 IDLDSMKNQN INLENSLGDV EARYKAQMEQ LNGVLLHLES ELAQTRAEGQ RQAQEYEALL 370 380 390 400 410 420 NIKVKLEAEI ATYRRLLEDG EDFSLNDALD SSNSMQTVQK TTTRKIVDGR VVSETNDTRV LRH

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Molecular cloning and characterization of the Endo B cytokeratin expressed in preimplantation mouse embryos." Singer P.A., Trevor K., Oshima R.G. J. Biol. Chem. 261:538-547(1986) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA], TISSUE SPECIFICITY, INDUCTION. Tissue: Endoderm.
[2]	"Cloning and characterization of keratin D, a murine endodermal cytoskeletal protein induced during in vitro differentiation of F9 teratocarcinoma cells." Alonso A., Weber T., Jorcano J.L. Roux's Arch. Dev. Biol. 196:16-21(1987) Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Teratocarcinoma.
[3]	"Nucleotide sequence and structure of the mouse cytokeratin endoB gene." Ichinose Y., Morita T., Zhang F., Srimahasongcram S., Tondella M.L.C., Matsumoto M., Nozaki M., Matsushiro A. Gene 70:85-95(1988) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: 129/SvJ. Tissue: Liver.
[4]	"The transcriptional landscape of the mammalian genome." Carninci P., Kasukawa T., Katayama S., Gough J., Frith M.C., Maeda N., Oyama R., Ravasi T., Lenhard B., Wells C., Kodzius R., Shimokawa K., Bajic V.B., Brenner S.E., Batalov S., Forrest A.R., Zavolan M., Davis M.J. , Wilming L.G., Aidinis V., Allen J.E., Ambesi-Impiombato A., Apweiler R., Aturaliya R.N., Bailey T.L., Bansal M., Baxter L., Beisel K.W., Bersano T., Bono H., Chalk A.M., Chiu K.P., Choudhary V., Christoffels A., Clutterbuck D.R., Crowe M.L., Dalla E., Dalrymple B.P., de Bono B., Della Gatta G., di Bernardo D., Down T., Engstrom P., Fagiolini M., Faulkner G., Fletcher C.F., Fukushima T., Furuno M., Futaki S., Gariboldi M., Georgii-Hemming P., Gingeras T.R., Gojobori T., Green R.E., Gustincich S., Harbers M., Hayashi Y., Hensch T.K., Hirokawa N., Hill D., Huminiecki L., Iacono M., Ikeo K., Iwama A., Ishikawa T., Jakt M., Kanapin A., Katoh M., Kawasawa Y., Kelso J., Kitamura H., Kitano H., Kollias G., Krishnan S.P., Kruger A., Kummerfeld S.K., Kurochkin I.V., Lareau L.F., Lazarevic D., Lipovich L., Liu J., Liuni S., McWilliam S., Madan Babu M., Madera M., Marchionni L., Matsuda H., Matsuzawa S., Miki H., Mignone F., Miyake S., Morris K., Mottagui-Tabar S., Mulder N., Nakano N., Nakauchi H., Ng P., Nilsson R., Nishiguchi S., Nishikawa S., Nori F., Ohara O., Okazaki Y., Orlando V., Pang K.C., Pavan W.J., Pavesi G., Pesole G., Petrovsky N., Piazza S., Reed J., Reid J.F., Ring B.Z., Ringwald M., Rost B., Ruan Y., Salzberg S.L., Sandelin A., Schneider C., Schoenbach C., Sekiguchi K., Semple C.A., Seno S., Sessa L., Sheng Y., Shibata Y., Shimada H., Shimada K., Silva D., Sinclair B., Sperling S., Stupka E., Sugiura K., Sultana R., Takenaka Y., Taki K., Tammoja K., Tan S.L., Tang S., Taylor M.S., Tegner J., Teichmann S.A., Ueda H.R., van Nimwegen E., Verardo R., Wei C.L., Yagi K., Yamanishi H., Zabarovsky E., Zhu S., Zimmer A., Hide W., Bult C., Grimmond S.M., Teasdale R.D., Liu E.T., Brusic V., Quackenbush J., Wahlestedt C., Mattick J.S., Hume D.A., Kai C., Sasaki D., Tomaru Y., Fukuda S., Kanamori-Katayama M., Suzuki M., Aoki J., Arakawa T., Iida J., Imamura K., Itoh M., Kato T., Kawaji H., Kawagashira N., Kawashima T., Kojima M., Kondo S., Konno H., Nakano K., Ninomiya N., Nishio T., Okada M., Plessy C., Shibata K., Shiraki T., Suzuki S., Tagami M., Waki K., Watahiki A., Okamura-Oho Y., Suzuki H., Kawai J., Hayashizaki Y. Science 309:1559-1563(2005) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Strain: C57BL/6J. Tissue: Blastocyst, Embryo and Placenta.
[5]	"The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)." The MGC Project Team Genome Res. 14:2121-2127(2004) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA]. Strain: C57BL/6. Tissue: Eye.
[6]	"Identification of the gene coding for the Endo B murine cytokeratin and its methylated, stable inactive state in mouse nonepithelial cells." Oshima R.G., Trevor K., Shevinsky L.H., Ryder O.A., Cecena G. Genes Dev. 2:505-516(1988) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 1-132, TISSUE SPECIFICITY.
[7]	"Embryonic expression of human keratin 18 and K18-beta-galactosidase fusion genes in transgenic mice." Thorey I.S., Meneses J.J., Neznanov N., Kulesh D.A., Pedersen R.A., Oshima R.G. Dev. Biol. 160:519-534(1993) [PubMed] [Europe PMC] [Abstract] Cited for: TISSUE SPECIFICITY, DEVELOPMENTAL STAGE.
[8]	"Monoclonal antibodies recognising stage and region specific epitopes in embryonic mouse palatal epithelial cells." Dixon M.J., Robinson V., White A., Ferguson M.W. J. Anat. 183:423-438(1993) [PubMed] [Europe PMC] [Abstract] Cited for: DEVELOPMENTAL STAGE.
[9]	"Caspase cleavage of keratin 18 and reorganization of intermediate filaments during epithelial cell apoptosis." Caulin C., Salvesen G.S., Oshima R.G. J. Cell Biol. 138:1379-1394(1997) [PubMed] [Europe PMC] [Abstract] Cited for: CLEAVAGE BY CASPASES.
[10]	"Superficial cell differentiation during embryonic and postnatal development of mouse urothelium." Erman A., Veranic P., Psenicnik M., Jezernik K. Tissue Cell 38:293-301(2006) [PubMed] [Europe PMC] [Abstract] Cited for: DEVELOPMENTAL STAGE.
[11]	"Interleukin-6 induces keratin expression in intestinal epithelial cells: potential role of keratin-8 in interleukin-6-induced barrier function alterations." Wang L., Srinivasan S., Theiss A.L., Merlin D., Sitaraman S.V. J. Biol. Chem. 282:8219-8227(2007) [PubMed] [Europe PMC] [Abstract] Cited for: FUNCTION, TISSUE SPECIFICITY, PHOSPHORYLATION, INDUCTION.
[12]	"Protein phosphorylation and expression profiling by Yin-yang multidimensional liquid chromatography (Yin-yang MDLC) mass spectrometry." Dai J., Jin W.-H., Sheng Q.-H., Shieh C.-H., Wu J.-R., Zeng R. J. Proteome Res. 6:250-262(2007) [PubMed] [Europe PMC] [Abstract] Cited for: PHOSPHORYLATION [LARGE SCALE ANALYSIS] AT SER-394 AND THR-397, MASS SPECTROMETRY. Tissue: Liver.
[13]	"Large-scale phosphorylation analysis of mouse liver." Villen J., Beausoleil S.A., Gerber S.A., Gygi S.P. Proc. Natl. Acad. Sci. U.S.A. 104:1488-1493(2007) [PubMed] [Europe PMC] [Abstract] Cited for: PHOSPHORYLATION [LARGE SCALE ANALYSIS] AT THR-8; THR-12; SER-31; SER-32 AND SER-35, MASS SPECTROMETRY. Tissue: Liver.
[14]	"p38 MAP kinase and MAPKAP kinases MK2/3 cooperatively phosphorylate epithelial keratins." Menon M.B., Schwermann J., Singh A.K., Franz-Wachtel M., Pabst O., Seidler U., Omary M.B., Kotlyarov A., Gaestel M. J. Biol. Chem. 285:33242-33251(2010) [PubMed] [Europe PMC] [Abstract] Cited for: PHOSPHORYLATION AT SER-52 BY MAPKAPK2 AND MAPKAPK3.
+	Additional computationally mapped references.

Cross-references

Sequence databases
EMBL GenBank DDBJ	M11686 mRNA. Translation: AAA39390.1. M36376 mRNA. Translation: AAA39373.1. M22832 Genomic DNA. Translation: AAA37552.1. AK145413 mRNA. Translation: BAE26424.1. AK167072 mRNA. Translation: BAE39232.1. AK167265 mRNA. Translation: BAE39378.1. AK167432 mRNA. Translation: BAE39519.1. AK167469 mRNA. Translation: BAE39553.1. AK167676 mRNA. Translation: BAE39725.1. BC089022 mRNA. Translation: AAH89022.1. Y00217 Genomic DNA. Translation: CAA68365.1.
IPI	IPI00311493.
PIR	I59463.
RefSeq	NP_034794.2. NM_010664.2.
UniGene	Mm.22479.
3D structure databases
ProteinModelPortal	P05784.
SMR	P05784. Positions 122-221, 290-378.
ModBase	Search...
PTM databases
PhosphoSite	P05784.
2D gel databases
SWISS-2DPAGE	P05784.
Proteomic databases
PaxDb	P05784.
PRIDE	P05784.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Genome annotation databases
Ensembl	ENSMUST00000023803; ENSMUSP00000023803; ENSMUSG00000023043.
GeneID	16668.
KEGG	mmu:16668.
UCSC	uc007xuj.2. mouse.
Organism-specific databases
CTD	3875.
MGI	MGI:96692. Krt18.
Phylogenomic databases
eggNOG	NOG150427.
GeneTree	ENSGT00560000076905.
HOGENOM	HOG000230975.
HOVERGEN	HBG013015.
InParanoid	P05784.
KO	K07604.
OMA	KKNHEEA.
OrthoDB	EOG4RV2S1.
Gene expression databases
Bgee	P05784.
CleanEx	MM_KRT18.
Genevestigator	P05784.
GermOnline	ENSMUSG00000023043. Mus musculus.
Family and domain databases
InterPro	IPR016044. F. IPR001664. IF. IPR018039. Intermediate_filament_CS. IPR002957. Keratin_I. [Graphical view]
PANTHER	PTHR23239. PTHR23239. 1 hit.
Pfam	PF00038. Filament. 1 hit. [Graphical view]
PRINTS	PR01248. TYPE1KERATIN.
PROSITE	PS00226. IF. 1 hit. [Graphical view]
ProtoNet	Search...
Other
ChiTaRS	KRT18. mouse.
NextBio	290387.
SOURCE	Search...

Entry information

Entry name

K1C18_MOUSE

Accession

Primary (citable) accession number: P05784
Secondary accession number(s): Q3TIX1 , Q3TJH6, Q3TJW7, Q61766

Entry history

Integrated into UniProtKB/Swiss-Prot:	November 1, 1988
Last sequence update:	May 29, 2007
Last modified:	May 1, 2013
This is version 118 of the entry and version 5 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program