title: Characterization of the pattern of ribosomal protein L19 production during the lifecycle of Leishmania spp.
abstract: Leishmania is a genus of protozoan parasites causing a wide clinical spectrum of diseases in humans. Analysis of a region of chromosome 6 from Leishmania major (Iribar et al.) showed that the transcript of a putative L19 ribosomal protein (RPL19) was most abundant at the amastigote stage. We therefore decided to characterize L19 protein abundance throughout the lifecycle of Leishmania. Differential expression of the L19 gene during development has been observed for all Leishmania species studied to date (L. major, L. braziliensis, L. donovani, and L. amazonensis). Immunoblotting with polyclonal antibodies against L. major RPL19 revealed that changes to L19 protein abundance follow a similar pattern in various species. The amount of L19 protein was higher in exponentially growing promastigotes than in stationary phase promastigotes. The L19 protein was barely detectable in amastigotes, despite the abundance of L19 transcripts observed in L. major at this stage. Immunofluorescence assays showed a granular, dispersed distribution of RPL19 throughout the cytoplasm. Subcellular fractionation confirmed the presence of the protein in the ribosomal fraction, but not in the cytosol of L. major. We generated a L. major transfectant bearing a plasmid-borne L19 gene. Overproduction of the L19 transcript and protein resulted in impaired growth of the transfectants in association with high polysome peaks. We also showed by metabolic labeling that L19 overexpressing clones display low rates of translation. These data suggest that L19 overexpression affects negatively translation elongation or termination. The lack of correlation between L19 transcript and protein abundances suggest that the translation of L19 is differentially controlled during development in the various species investigated.
authors.affiliation: Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, no. 3900, CEP 14049-900 Ribeirão Preto, São Paulo, Brazil.
authors.forename: Janayna Hammes
authors.initials: JH
authors.lastname: de Almeida-Bizzo
authors.affiliation: Laboratório de Regulação da Expressão Gênica, Instituto Carlos Chagas, Fiocruz-Paraná, Curitiba, Paraná, Brazil.
authors.forename: Lysangela Ronalte
authors.initials: LR
authors.lastname: Alves
authors.affiliation: Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, no. 3900, CEP 14049-900 Ribeirão Preto, São Paulo, Brazil.
authors.forename: Felipe F
authors.initials: FF
authors.lastname: Castro
authors.affiliation: Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, no. 3900, CEP 14049-900 Ribeirão Preto, São Paulo, Brazil.
authors.forename: Juliana Bório Ferreira
authors.initials: JB
authors.lastname: Garcia
authors.affiliation: Laboratório de Regulação da Expressão Gênica, Instituto Carlos Chagas, Fiocruz-Paraná, Curitiba, Paraná, Brazil.
authors.forename: Samuel
authors.initials: S
authors.lastname: Goldenberg
authors.affiliation: Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade Medicina de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, no. 3900, CEP 14049-900 Ribeirão Preto, São Paulo, Brazil. Electronic address: akcruz@fmrp.usp.br.
authors.forename: Angela Kaysel
authors.initials: AK
authors.lastname: Cruz
mesh_terms: D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis / Q000276:immunology; D015152:Blotting, Northern; D015153:Blotting, Western; D003001:Cloning, Molecular; D005260:Female; D005455:Fluorescent Antibody Technique; D018507:Gene Expression Regulation, Developmental / Q000235:genetics / Q000502:physiology*; D005822:Genetic Vectors; D007891:Leishmania / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D007896:Leishmaniasis / Q000469:parasitology*; D008018:Life Cycle Stages / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011132:Polyribosomes / Q000737:chemistry; D012333:RNA, Messenger / Q000032:analysis / Q000302:isolation & purification; D016053:RNA, Protozoan / Q000032:analysis / Q000302:isolation & purification; D011817:Rabbits; D012269:Ribosomal Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D012270:Ribosomes / Q000235:genetics
chemical_list: D000913:Antibodies, Protozoan; D012333:RNA, Messenger; D016053:RNA, Protozoan; D012269:Ribosomal Proteins
keywords: Gene expression; L19; Leishmania; Ribosomal protein