ID   K1C20_BOVIN             Reviewed;         422 AA.
AC   A6QQQ9;
DT   23-OCT-2007, integrated into UniProtKB/Swiss-Prot.
DT   13-NOV-2007, sequence version 2.
DT   25-MAY-2022, entry version 71.
DE   RecName: Full=Keratin, type I cytoskeletal 20;
DE   AltName: Full=Cytokeratin-20;
DE            Short=CK-20;
DE   AltName: Full=Keratin-20;
DE            Short=K20;
GN   Name=KRT20 {ECO:0000250|UniProtKB:P35900};
OS   Bos taurus (Bovine).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi; Mammalia;
OC   Eutheria; Laurasiatheria; Artiodactyla; Ruminantia; Pecora; Bovidae;
OC   Bovinae; Bos.
OX   NCBI_TaxID=9913;
RN   [1] {ECO:0000312|EMBL:AAI49956.1}
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA].
RC   STRAIN=Crossbred X Angus {ECO:0000312|EMBL:AAI49956.1};
RC   TISSUE=Ileum {ECO:0000312|EMBL:AAI49956.1};
RG   NIH - Mammalian Gene Collection (MGC) project;
RL   Submitted (JUL-2007) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Plays a significant role in maintaining keratin filament
CC       organization in intestinal epithelia. When phosphorylated, plays a role
CC       in the secretion of mucin in the small intestine (By similarity).
CC       {ECO:0000250|UniProtKB:Q9D312}.
CC   -!- SUBUNIT: Heterotetramer of two type I and two type II keratins.
CC       Associates with KRT8 (By similarity). {ECO:0000250|UniProtKB:P35900,
CC       ECO:0000305}.
CC   -!- PTM: Hyperphosphorylation at Ser-13 occurs during the early stages of
CC       apoptosis but becomes less prominent during the later stages.
CC       Phosphorylation at Ser-13 also increases in response to stress brought
CC       on by cell injury (By similarity). {ECO:0000250|UniProtKB:P35900,
CC       ECO:0000250|UniProtKB:Q9D312}.
CC   -!- PTM: Proteolytically cleaved by caspases during apoptosis. Cleavage
CC       occurs at Asp-228 (By similarity). {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   -!- SEQUENCE CAUTION:
CC       Sequence=AAI49956.1; Type=Erroneous initiation; Evidence={ECO:0000305};
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DR   EMBL; BC149955; AAI49956.1; ALT_INIT; mRNA.
DR   RefSeq; NP_001095321.1; NM_001101851.2.
DR   AlphaFoldDB; A6QQQ9; -.
DR   SMR; A6QQQ9; -.
DR   STRING; 9913.ENSBTAP00000010255; -.
DR   PaxDb; A6QQQ9; -.
DR   PeptideAtlas; A6QQQ9; -.
DR   PRIDE; A6QQQ9; -.
DR   GeneID; 505214; -.
DR   KEGG; bta:505214; -.
DR   CTD; 54474; -.
DR   eggNOG; ENOG502QUY3; Eukaryota.
DR   HOGENOM; CLU_012560_8_2_1; -.
DR   InParanoid; A6QQQ9; -.
DR   OrthoDB; 798081at2759; -.
DR   Proteomes; UP000009136; Unplaced.
DR   GO; GO:0005856; C:cytoskeleton; IBA:GO_Central.
DR   GO; GO:0005882; C:intermediate filament; IEA:UniProtKB-KW.
DR   GO; GO:0005198; F:structural molecule activity; IEA:InterPro.
DR   GO; GO:0006915; P:apoptotic process; IEA:UniProtKB-KW.
DR   GO; GO:0009267; P:cellular response to starvation; ISS:UniProtKB.
DR   GO; GO:0030855; P:epithelial cell differentiation; IBA:GO_Central.
DR   GO; GO:0045109; P:intermediate filament organization; ISS:UniProtKB.
DR   GO; GO:0050708; P:regulation of protein secretion; ISS:UniProtKB.
DR   InterPro; IPR018039; IF_conserved.
DR   InterPro; IPR039008; IF_rod_dom.
DR   InterPro; IPR002957; Keratin_I.
DR   PANTHER; PTHR23239; PTHR23239; 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   Apoptosis; Coiled coil; Intermediate filament; Keratin; Phosphoprotein;
KW   Reference proteome.
FT   CHAIN           1..422
FT                   /note="Keratin, type I cytoskeletal 20"
FT                   /id="PRO_0000308357"
FT   DOMAIN          70..381
FT                   /note="IF rod"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01188"
FT   REGION          1..69
FT                   /note="Head"
FT   REGION          1..25
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   REGION          70..105
FT                   /note="Coil 1A"
FT   REGION          106..123
FT                   /note="Linker 1"
FT   REGION          124..215
FT                   /note="Coil 1B"
FT   REGION          216..238
FT                   /note="Linker 12"
FT   REGION          239..377
FT                   /note="Coil 2"
FT   REGION          378..422
FT                   /note="Tail"
FT   SITE            228..229
FT                   /note="Cleavage; by caspases"
FT                   /evidence="ECO:0000250"
FT   MOD_RES         13
FT                   /note="Phosphoserine; by MAPKAPK2, MAPKAPK3 and PKC"
FT                   /evidence="ECO:0000250|UniProtKB:P35900"
FT   MOD_RES         16
FT                   /note="Phosphoserine"
FT                   /evidence="ECO:0000250|UniProtKB:Q9D312"
FT   MOD_RES         26
FT                   /note="Phosphoserine"
FT                   /evidence="ECO:0000250|UniProtKB:P25030"
FT   CONFLICT        1
FT                   /note="M -> V (in Ref. 1; AAI49956)"
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   422 AA;  48172 MW;  2F0890CBE0400B1C CRC64;
     MDFSQRSFHR SLSSSSQSPG LSMSSSIYRR GVAPSVYGGA GGHGTRISTS RHLANYGSVP
     AGGNLFAGNE KMTMQNLNDR LASYLERVRS LEQSNSHLEQ QIKHWYETNT PSTGRDHSAY
     MGQIKELRDQ IKDAQLQNAR CVLQIDNAKL AMEDFRLKYE AERGICQTVV ADLHGLKRVF
     DELTLTKADL EIQIEELTKD LHLLQKEHEE EVRSLRAHLG NNVNVEVDAP PSLNLGAIMN
     EMRQKYDAMA QENLQKAKEQ FEIQINDLQQ QVTVSTEELK GTKDQIKEQR HTYQVLELEL
     QSLLNMKEAL EHTLEETNAR YGSHLAKIQA RLNSLEGQLV QVRTDTERQI HEYNILLDIK
     IRLEQEIATY RRLLEGEDVK EYQLSTLDEK DIKKTRKIKT VVQEVVDGKV VSSEVKEVEE
     SV