Figure 1.
Identification of a MEK1K57N mutation in human lung adenocarcinoma. A, reverse sequencing chromatograms display presence of a G→T mutation at position 171 in exon 2 of MEK1 in two tumor samples. This mutation was absent from matched normal control samples. (Forward sequence chromatograms not shown due to space constraints.) B, protein sequence alignment of MEK1 from various species shows that K57 is a highly conserved residue. Numbers indicate amino acid positions. C, K57N is located in between the nuclear export signal (NES) and the kinase domain of MEK1. D, docking domain. Shown are mutations found in patients with cardio-facio-cutaneous (CFC) syndrome.