1. Antibody analysis of Erk.
Antibody analysis of Erk. (A) Primary sequence of the His6‐tagged Erk2 from Xenopus laevis used in the paper, showing two tryptic peptides identified as being phosphorylated (underlined): the central peptide contains the two activating phosphorylation sites in the canonical TEY motif and the N‐terminal peptide (omitting the N‐terminal M, which is cleaved) contains the His6 tag and the two novel S‐phosphorylation sites discussed in the text. The phospho‐sites are marked in large, bold, blue font. (B) Ribbon diagram of Erk2 from Rattus norvegicus (PDB‐2ERK) showing activating phosphorylations on T and Y (yellow). (C) Summary of amount/intensity relationship for each antibody. The measures R2 and α are explained in the text and derived from the data in Supplementary Figure 1. (D) Phospho‐form measurements. Each vertical sub‐panel shows the results from the antibody listed at the top of the sub‐panel. Erk samples are listed horizontally at the bottom with X denoting sample Erk‐X. Each bar gives the ratio of the fluorescence intensity of the corresponding antibody to the intensity of the anti‐total Erk antibody. Both antibodies were multiplexed on the same gel. Each of the four Erk samples were run in triplicate on the same gel and each gel was repeated three times; error bars give the mean±s.d. of the nine data points. The underlying data are shown in Supplementary Figure 2. Note that there is no sum normalisation and it is coincidental that values lie between 0 and 1. The arrows show particular comparisons discussed in the text. Source data is available for this figure at
Sudhakaran Prabakaran et al. Mol Syst Biol 2011;7:482
© as stated in the article, figure or figure legend