keratin, type II cytoskeletal 7; cytokeratin-7; CK-7; keratin-7; K7; sarcolectin (KRT7, SCL)

Function

• blocks interferon-dependent interphase
• stimulates DNA synthesis in cells
• interacts with eukaryotic translation initiator factor 3 (eIF3)
• subunit EIF3S10 of eIF3

Structure

• heterotetramer of 2 type 1 & 2 type 2 keratins
• Arg-20 is dimethylated, probably to asymmetric dimethylarginine
• belongs to the intermediate filament family

Compartment

cytoplasm

Expression

• subset of endothelial cells in normal tissues
• present in many simple, pseudostratified & ductal epithelia & mesothelial cells
• rare in colonic epithelium, hepatocytes, prostatic acinar cells
• expressed in cultured epidermal, bronchial & mesothelial cells but absent in colon, ectocervix & liver
• observed throughout the glandular cells in the junction between stomach & esophagus but is absent in the esophagus
• up-regulated by retinoic acid

Pathology

• positive for antibody staining in
  • mesothelioma
  • transitional cell carcinoma
  • neuroendocrine carcinoma
  • thymic carcinoma
  • breast carcinoma
  • lung adenocarcinoma
  • ovarian carcinoma
  • endometrial carcinoma
  • pancreatic adenocarcinoma
  • fibrolamellar hepatocellular carcinoma
• mostly negative for antibody staining in
  • renal cell carcinoma
  • prostate cancer
  • squamous cell carcinoma
  • small cell carcinoma
  • rare in colorectal adenocarcinoma
  • other variams of hepatocellular carcinoma
• involved in the translational regulation of the human papillomavirus type 16 E7 mRNA (HPV16 E7)

More general terms

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

Database

• UniProt: http://www.uniprot.org/uniprot/P08729.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=3855
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:3855
• OMIM: https://mirror.omim.org/entry/148059