ID   K1C18_XENTR             Reviewed;         429 AA.
AC   Q6P864; Q28H80;
DT   29-MAY-2007, integrated into UniProtKB/Swiss-Prot.
DT   05-JUL-2004, sequence version 1.
DT   03-AUG-2022, entry version 85.
DE   RecName: Full=Keratin, type I cytoskeletal 18;
DE   AltName: Full=Cytokeratin-18;
DE            Short=CK-18;
DE   AltName: Full=Keratin-18;
DE            Short=K18;
GN   Name=krt18 {ECO:0000312|EMBL:CAJ82137.1}; ORFNames=TEgg011c19.1;
OS   Xenopus tropicalis (Western clawed frog) (Silurana tropicalis).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Amphibia;
OC   Batrachia; Anura; Pipoidea; Pipidae; Xenopodinae; Xenopus; Silurana.
OX   NCBI_TaxID=8364;
RN   [1] {ECO:0000312|EMBL:CAJ82137.1}
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC   TISSUE=Egg {ECO:0000312|EMBL:CAJ82137.1};
RG   Sanger Xenopus tropicalis EST/cDNA project;
RL   Submitted (OCT-2006) to the EMBL/GenBank/DDBJ databases.
RN   [2] {ECO:0000312|EMBL:CAJ82137.1}
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC   TISSUE=Neurula {ECO:0000312|EMBL:AAH61366.1};
RG   NIH - Xenopus Gene Collection (XGC) project;
RL   Submitted (NOV-2003) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: When phosphorylated, plays a role in filament reorganization.
CC       {ECO:0000250}.
CC   -!- SUBUNIT: Heterotetramer of two type I and two type II keratins.
CC       Keratin-18 associates with keratin-8 (By similarity). {ECO:0000250}.
CC   -!- PTM: Phosphorylated. {ECO:0000250}.
CC   -!- PTM: Proteolytically cleaved by caspases during epithelial cell
CC       apoptosis. {ECO:0000250}.
CC   -!- MISCELLANEOUS: There are two types of cytoskeletal and microfibrillar
CC       keratin: I (acidic; 40-55 kDa) and II (neutral to basic; 56-70 kDa).
CC       {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the intermediate filament family.
CC       {ECO:0000255|PROSITE-ProRule:PRU01188}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; CR761001; CAJ82137.1; -; mRNA.
DR   EMBL; BC061366; AAH61366.1; -; mRNA.
DR   RefSeq; NP_988944.1; NM_203613.1.
DR   AlphaFoldDB; Q6P864; -.
DR   SMR; Q6P864; -.
DR   STRING; 8364.ENSXETP00000019968; -.
DR   PaxDb; Q6P864; -.
DR   DNASU; 394541; -.
DR   GeneID; 394541; -.
DR   KEGG; xtr:394541; -.
DR   CTD; 394541; -.
DR   Xenbase; XB-GENE-5820467; krt18.1.
DR   eggNOG; ENOG502QUS8; Eukaryota.
DR   InParanoid; Q6P864; -.
DR   OrthoDB; 711591at2759; -.
DR   Reactome; R-XTR-6805567; Keratinization.
DR   Reactome; R-XTR-6809371; Formation of the cornified envelope.
DR   Proteomes; UP000008143; Chromosome 2.
DR   Proteomes; UP000790000; Unplaced.
DR   GO; GO:0005856; C:cytoskeleton; IBA:GO_Central.
DR   GO; GO:0045095; C:keratin filament; IBA:GO_Central.
DR   GO; GO:0005198; F:structural molecule activity; IEA:InterPro.
DR   GO; GO:0045104; P:intermediate filament cytoskeleton organization; IBA:GO_Central.
DR   InterPro; IPR018039; IF_conserved.
DR   InterPro; IPR039008; IF_rod_dom.
DR   InterPro; IPR027695; Keratin-18.
DR   InterPro; IPR002957; Keratin_I.
DR   PANTHER; PTHR23239; PTHR23239; 1.
DR   PANTHER; PTHR23239:SF349; PTHR23239:SF349; 1.
DR   Pfam; PF00038; Filament; 1.
DR   PRINTS; PR01248; TYPE1KERATIN.
DR   SMART; SM01391; Filament; 1.
DR   PROSITE; PS00226; IF_ROD_1; 1.
DR   PROSITE; PS51842; IF_ROD_2; 1.
PE   2: Evidence at transcript level;
KW   Coiled coil; Intermediate filament; Keratin; Phosphoprotein;
KW   Reference proteome.
FT   INIT_MET        1
FT                   /note="Removed"
FT                   /evidence="ECO:0000250|UniProtKB:P05783"
FT   CHAIN           2..429
FT                   /note="Keratin, type I cytoskeletal 18"
FT                   /evidence="ECO:0000250|UniProtKB:P05783"
FT                   /id="PRO_0000289078"
FT   DOMAIN          79..389
FT                   /note="IF rod"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01188"
FT   REGION          2..78
FT                   /note="Head"
FT                   /evidence="ECO:0000255"
FT   REGION          79..114
FT                   /note="Coil 1A"
FT                   /evidence="ECO:0000255"
FT   REGION          115..130
FT                   /note="Linker 1"
FT                   /evidence="ECO:0000255"
FT   REGION          131..222
FT                   /note="Coil 1B"
FT                   /evidence="ECO:0000255"
FT   REGION          223..246
FT                   /note="Linker 12"
FT                   /evidence="ECO:0000255"
FT   REGION          247..385
FT                   /note="Coil 2"
FT                   /evidence="ECO:0000255"
FT   REGION          386..429
FT                   /note="Tail"
FT                   /evidence="ECO:0000255"
FT   SITE            236..237
FT                   /note="Cleavage; by caspases"
FT                   /evidence="ECO:0000250"
FT   SITE            329
FT                   /note="Stutter"
FT                   /evidence="ECO:0000255"
FT   CONFLICT        24
FT                   /note="S -> A (in Ref. 1; CAJ82137)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   429 AA;  47613 MW;  416F307F66D55101 CRC64;
     MSYSRSVYSS SSVVGGSPYR SLSSAPRFIP SSSAASVHAG AGGSGARISV SRVSSVGSGF
     GGGYSGVSNV NLIGGGQNEK ETMQDLNDRL ASYLERVRSL EAANKKLEVQ IRQHTEKKGP
     SKDWSPYYKT IEDLRKQVFD STLENSQLVL QIDNARLAAD DFRVKYEAEM AIRMSVEGDI
     TGLRKLIDDT NVSRMNLENE IESLKEELIF LKKNHQDDVT ELQAQVARSA VTVEVDAPKS
     QDLGKIMTEL RAQYDGLAQK NRDDVEKWYQ SKVDEHTVQV NLDTEALHSA KSSVTDLRRT
     VQSLEIELES LRNQKASLEG TLHDTEARYA MELEMLGGTA MAMEAELVQV RSDCQRQQQE
     YQALLNTKMK LEAEIHTYRR LLEGDGSFDL QDAVPTVTTQ TVKKVITTTQ RIVDGKVVSE
     SNDTEVLKS