FIGURE 1:

Nonmuscle β- and γ-actin are novel prolyl hydroxylated proteins. (A) Schematic representation of the SILAC proteomic screening strategy. (B) Two prolyl hydroxylated peptides of the nonmuscle actin were identified by mass spectrometry. Hydroxyproline residues are underlined. (C, D) MS/MS spectrum of the prolyl hydroxylated nonmuscle actin peptide. Hydroxyproline residues are shown in lowercase. (E) Mapping hydroxylated proline residues Pro-307 and Pro-322 (red) in the protein structure of actin. Hydroxylated Pro-307 and Pro-322 were mapped by SWISS-MODEL (Arnold et al., 2006) using the protein structure of human β-actin (PDB ID 3BYH) as template (Galkin et al., 2008) and visualized using PyMOL (Schrödinger LLC, 2008).