ID   K1C18_CARAU             Reviewed;         435 AA.
AC   Q07427;
DT   29-MAY-2007, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   25-MAY-2022, entry version 68.
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;
OS   Carassius auratus (Goldfish).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Actinopterygii; Neopterygii; Teleostei; Ostariophysi; Cypriniformes;
OC   Cyprinidae; Cyprininae; Carassius.
OX   NCBI_TaxID=7957;
RN   [1] {ECO:0000305, ECO:0000312|EMBL:AAC38007.1}
RP   NUCLEOTIDE SEQUENCE [MRNA], AND TISSUE SPECIFICITY.
RC   TISSUE=Optic nerve {ECO:0000312|EMBL:AAC38007.1};
RX   PubMed=7515399; DOI=10.1002/cne.903400211;
RA   Druger R.K., Glasgow E., Fuchs C., Levine E.M., Matthews J.P., Park C.Y.,
RA   Schechter N.;
RT   "Complex expression of keratins in goldfish optic nerve.";
RL   J. Comp. Neurol. 340:269-280(1994).
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   -!- TISSUE SPECIFICITY: Abundantly expressed in an even distribution
CC       throughout the optic nerve, localizing specifically to the astrocyte
CC       domains. Moderately expressed in spinal cord, brain, liver and oocytes.
CC       {ECO:0000269|PubMed:7515399}.
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}.
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DR   EMBL; L09744; AAC38007.1; -; mRNA.
DR   AlphaFoldDB; Q07427; -.
DR   SMR; Q07427; -.
DR   PRIDE; Q07427; -.
DR   Proteomes; UP000515129; Genome assembly.
DR   GO; GO:0005882; C:intermediate filament; IEA:UniProtKB-KW.
DR   GO; GO:0005198; F:structural molecule activity; IEA:InterPro.
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..435
FT                   /note="Keratin, type I cytoskeletal 18"
FT                   /evidence="ECO:0000250|UniProtKB:P05783"
FT                   /id="PRO_0000289071"
FT   DOMAIN          89..399
FT                   /note="IF rod"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01188"
FT   REGION          1..36
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          2..88
FT                   /note="Head"
FT                   /evidence="ECO:0000255"
FT   REGION          89..123
FT                   /note="Coil 1A"
FT                   /evidence="ECO:0000255"
FT   REGION          124..140
FT                   /note="Linker 1"
FT                   /evidence="ECO:0000255"
FT   REGION          141..232
FT                   /note="Coil 1B"
FT                   /evidence="ECO:0000255"
FT   REGION          233..256
FT                   /note="Linker 12"
FT                   /evidence="ECO:0000255"
FT   REGION          257..394
FT                   /note="Coil 2"
FT                   /evidence="ECO:0000255"
FT   REGION          395..435
FT                   /note="Tail"
FT                   /evidence="ECO:0000255"
FT   SITE            246..247
FT                   /note="Cleavage; by caspases"
FT                   /evidence="ECO:0000250"
FT   SITE            339
FT                   /note="Stutter"
FT                   /evidence="ECO:0000255"
SQ   SEQUENCE   435 AA;  49179 MW;  C5346F321732ABA7 CRC64;
     MSLRSSYSVR SSTSQVPVSQ MSQMSQMSIK RTTNVPTYRA ARSTAAAGQG TRISSASYSG
     VRSGVGLPSM SSSIHVSATG ATGDIMGNEK MAMQNLNDRL ASYLRSETLE QANSKLELKI
     REALEKKGPE VCDYSRFQPI IDDLRRKIFD ATSNNARLVL QIDNARLAAD DFRVKYDSEL
     SIRQGVEADI AGLRKVIDDT NMNRMNLESE IEALKEELIF LKKNHDNEVM ELRNQISHSG
     VQVDVDAPKG QDLAKIMEEI RSKYEKMALK NQEELKAWHE SQITEVQVQV IQNTEALEGA
     RTEVNELRRQ IQTLEIELES QRNLKGSLEA TLRDTEMRYN MEIESLNAVT MQLEAELTQL
     RNNIQHQTQE YEALLNLKMK LEAEIATYRR LLDGGDFKLQ DALEEQKRVK VMTVTQTLVD
     GKVVSSSTET KEKKF