title: A mutation in the common docking domain of ERK2 in a human cancer cell line, which was associated with its constitutive phosphorylation.
abstract: The EGFR/Ras/Raf/MEK/ERK pathway is a major pathway involved in the control of growth signals, cell survival and differentiation. Mutations of signaling components, such as EGFR (c-erbB1), Ras, and B-Raf, have been shown to play roles in the genesis of human cancer, while point mutation of ERK has not been reported. In this study, we present evidence for a mutation in an oral squamous cell carcinoma cell line, HSC6. PCR-amplification of cDNA, cloning and sequencing resulted in the identification of glutamic acid to lysine substitution at codon 322 (E322K) that occurred in the common docking (CD) domain of ERK2. The mutant protein contributed towards faster-migration in SDS-PAGE, and constitutive phosphorylation in a MEK-dependent manner. The transient transfection of the mutant ERK2 in 293T cells resulted in the expression of the same faster-migrating band in SDS-PAGE as was detected in HSC6 cells, which was preferentially phosphorylated relative to endogenous wild-type ERK2. The present study is the first to report ERK2 substitution mutation in a human cancer cell line which resulted in constitutive phosphorylation.
authors.affiliation: Department of Molecular Cellular Oncology and Microbiology, Graduate School of Medicine and Dentistry, Tokyo Medical and Dental University, 113-8549 Tokyo, Japan.
authors.forename: Ramanathan
authors.initials: R
authors.lastname: Arvind
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Shimamoto
authors.forename: Fumio
authors.initials: F
authors.lastname: Momose
authors.forename: Teruo
authors.initials: T
authors.lastname: Amagasa
authors.forename: Ken
authors.initials: K
authors.lastname: Omura
authors.forename: Nobuo
authors.initials: N
authors.lastname: Tsuchida
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D002294:Carcinoma, Squamous Cell / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002460:Cell Line; D045744:Cell Line, Tumor; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics* / Q000378:metabolism; D009062:Mouth Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D020125:Mutation, Missense; D010766:Phosphorylation; D017354:Point Mutation; D017386:Sequence Homology, Amino Acid; D014162:Transfection
chemical_list: D007527:Isoenzymes; D019950:Mitogen-Activated Protein Kinase 1