Fig. 3. The N-terminus of Arl8b is acetylated. (A) Alignment of human Arl8a and Arl8b with their relatives from Xenopus tropicalis, Drosophila melanogaster, Caenorhabditis elegans, Schistosoma japonicum, Arabidopsis thaliana, Neurospora crassa and Dictyostelium discoideum. Sequences were aligned with CLUSTAL W, and shaded in cases where more than half of the residues are related (grey) or identical (black). Hydrophobic amino acids are shown in red, arrows indicate the mutants analysed with combined point mutations in hydrophobic residues (red), or in individual conserved residues (black). (B) Alignment of the N-termini of human Arl8b, Arl1, Arf1 and ARFRP1. The second residue is shown in red. (C) MALDI mass spectrum of tryptic peptides from Arl8b-HA immunoprecipitated from transfected COS cells. Peptides with masses corresponding to expected digestion products of Arl8b are indicated with the sequence for the N-terminal peptide, or with residue numbers (o, oxidised). (D) Anti-HA immunoprecipitates from COS cells expressing LAT-HA or Arl8b-HA and labelled with [³H]palmitate. After gel electrophoresis, the precipitates were either probed with anti-HA antibodies or ³H-detected with fluorography.