title: A combined proteomic and transcriptomic approach to the study of stage differentiation in Leishmania infantum.
abstract: Protozoan parasites of the genus Leishmania are found as promastigotes in the sandfly vector and as amastigotes in mammalian macrophages. Mechanisms controlling stage-regulated gene expression in these organisms are poorly understood. Here, we applied a comprehensive approach consisting of protein prefractionation, global proteomics and targeted DNA microarray analysis to the study of stage differentiation in Leishmania. By excluding some abundant structural proteins and reducing complexity, we detected and identified numerous novel differentially expressed protein isoforms in L. infantum. Using 2-D gels, over 2200 protein isoforms were visualized in each developmental stage. Of these, 6.1% were strongly increased or appeared unique in the promastigote stage, while the relative amounts of 12.4% were increased in amastigotes. Amastigote-specific protein isoform and mRNA expression trends correlated modestly (53%), while no correlation was found for promastigote-specific spots. Even where direction of regulation was similar, fold-changes were more modest at the RNA than protein level. Many proteins were present in multiple spots, suggesting that PTM is extensive in this organism. In several cases, different isoforms appeared to be specific to different life stages. Our results suggest that post-transcriptional controls at translational and post-translational levels could play major roles in differentiation in Leishmania parasites.
authors.affiliation: Infectious Diseases Research Centre, CHUL Research Centre and Division of Microbiology, Faculty of Medicine, Laval University, Quebec, Canada.
authors.forename: François
authors.initials: F
authors.lastname: McNicoll
authors.forename: Jolyne
authors.initials: J
authors.lastname: Drummelsmith
authors.forename: Michaela
authors.initials: M
authors.lastname: Müller
authors.forename: Eric
authors.initials: E
authors.lastname: Madore
authors.forename: Nathalie
authors.initials: N
authors.lastname: Boilard
authors.forename: Marc
authors.initials: M
authors.lastname: Ouellette
authors.forename: Barbara
authors.initials: B
authors.lastname: Papadopoulou
mesh_terms: D000818:Animals; D015180:Electrophoresis, Gel, Two-Dimensional; D018507:Gene Expression Regulation, Developmental; D018390:Gene Targeting; D017125:Genes, Protozoan; D018314:Leishmania infantum / Q000737:chemistry / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D008018:Life Cycle Stages; D020411:Oligonucleotide Array Sequence Analysis; D010446:Peptide Fragments / Q000737:chemistry; D010449:Peptide Mapping; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D020543:Proteome / Q000032:analysis; D040901:Proteomics / Q000379:methods*; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D010446:Peptide Fragments; D020033:Protein Isoforms; D020543:Proteome; D015800:Protozoan Proteins; D012333:RNA, Messenger