Fig. 1: KIAPs identified through comparative proteomics.

a Experimental flow of sample preparation for the comparative proteomic using attached in vitro haptomonad-like promastigotes and non-attached in vitro promastigotes. Scanning electron microscopy images show an intact in vitro haptomonad-like promastigote (1), an in vitro haptomonad-like promastigote after membrane extraction (2) and an attached flagellum remained on the substrate after cell body microtubule depolymerisation (3; the numbers correspond to those in the experimental flow, and each sample was prepared at the step indicated by the corresponding number). Arrowheads: attached flagellum. The scanning electron micrographs are representative of n = 2 independent sample preparations. b Localisation of mNeonGreen (mNG)-tagged KIAPs in non-attached in vitro promastigotes (leptomonad; see also Supplementary Fig. 2) and attached in vitro haptomonad-like promastigotes. Representative images from at least n = 3 independent sample preparations are shown. In the merged images, the overlays of the phase contrast, mNG (green) and Hoechst-stained DNA (blue) images are shown. c Protein domains of L. mexicana KIAPs. Domain names and ranges in the amino acid sequence are shown above coloured boxes. The amino acid (a.a.) length of each protein is indicated to the right of each structure. SP: signal peptide, DUF: domain of unknown function, TM: transmembrane domain. d Phylogenetic tree of kinetoplastids based on 18S rRNA sequences showing conservation of KIAPs across the kinetoplastids. The presence (filled circle) or absence (open circle) of an ortholog of a gene family is indicated on the right-hand side of the tree. The species indicated in blue are known to adhere to cuticle or wax layers in the insect vector and the species indicated in green are known to adhere to the cell membrane in the insect vector. Bodo saltans exhibits transient adhesion to substrates in the environment. Branch lengths do not represent evolutionary time.