keratin, type 2 cytoskeletal 1; cytokeratin-1; CK-1; keratin-1; K1; 67 kD cytokeratin; hair alpha protein (KRT1 KRTA)

Function

• may regulate activity of kinases such as PKC & SRC via binding to integrin beta-1 (ITB1) & the receptor of activated protein kinase C (RACK1/GNB2L1)
• undergoes deimination of some Arg (citrullination)
• heterotetramer of 2 type 1 keratins & 2 type 2 keratins
• cytokeratin-1 is generally associated with cytokeratin-10
• interacts with ITGB1 in the presence of GNB2L1 & SRC, & with GNB2L1

Structure

• type 2 keratin
• belongs to the intermediate filament family

Compartment

• cell membrane
• located on plasma membrane of neuroblastoma NMB7 cells

Expression

• isolated from neonatal foreskin
• 67-kD type 2 cytokeratins are expressed in terminally differentiating epidermis
• cytokeratin-1 & cytokeratin-10 are expressed in keratinizing squamous epithelium & squamous cell carcinomas

Pathology

• defects in KRT1 are a cause of
  • epidermolytic hyperkeratosis
  • palmoplantar keratoderma non-epidermolytic
  • ichthyosis annular epidermolytic
• defects in KRT1 are the cause of
  • ichthyosis hystrix Curth-Macklin type
  • palmoplantar keratoderma striate type-3

Polymorphism

• there are 2 size variants of KRT1, termed allele 1A & allele 1B with allelic frequencies of 0.61 & 0.39
• allele 1B lacks 7 residues compared to allele 1A

More general terms

• cytokeratin, epithelial keratins or soft alpha-keratins
• phosphoprotein

Database

• UniProt: http://www.uniprot.org/uniprot/P04264.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=3848
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:3848
• OMIM: https://mirror.omim.org/entry/113800
• OMIM: https://mirror.omim.org/entry/139350
• OMIM: https://mirror.omim.org/entry/146590
• OMIM: https://mirror.omim.org/entry/600962
• OMIM: https://mirror.omim.org/entry/607602
• OMIM: https://mirror.omim.org/entry/607654