TY - JOUR
T1 - The characterization and evolutionary relationships of a trypanosomal thiolase
AU - Mazet, Muriel
AU - Harijan, Rajesh K.
AU - Kiema, Tiila Riika
AU - Haapalainen, Antti M.
AU - Morand, Pauline
AU - Morales, Jorge
AU - Bringaud, Frédéric
AU - Wierenga, Rik K.
AU - Michels, Paul A.M.
N1 - Funding Information:
We thank Dr. Barycki (University of Nebraska, USA) for providing the plasmid of SC-HAD. We are grateful to The Institute for Genomic Research (TIGR), USA and the Wellcome Trust Sanger Institute, UK for the chromosome sequences accessible in the trypanosomatid genome GeneDB ( http://www.genedb.org/Homepage ). This research was supported through grants to PAMM from the ‘Fonds de la Recherche Scientifique’ (F.R.S-FNRS) of the ‘Communauté française de Belgique’ and the Interuniversity Attraction Poles – Belgian Federal Office for Scientific, Technical and Cultural Affairs. MM acknowledges a postdoctoral fellowship from the F.R.S-FNRS. FB and PM are supported by the ‘Agence Nationale de la Recherche’ (ANR) programs METABOTRYP (ANR-MIME-2007 call), SYSTRYP (ANR-BBSRC-2007 call) and ACETOTRYP (ANR-BLANC-SVSE3-2010 call), the ‘Conseil Régional d’Aquitaine’, the ‘Université Bordeaux Segalen’ and the CNRS, France. Support from the Academy of Finland (grant 131795 to RW) is also gratefully acknowledged. We would also like to acknowledge expert support from Ville Ratas.
PY - 2011/10
Y1 - 2011/10
N2 - Thiolases are enzymes that remove an acetyl-coenzyme A group from acyl-CoA in the catabolic β-oxidation of fatty acids, or catalyse the reverse condensation reaction for anabolic processes such as the biosynthesis of sterols and ketone bodies. In humans, six homologous isoforms of thiolase have been described, differing from each other in sequence, oligomeric state, substrate specificity and subcellular localization. A bioinformatics analysis of parasite genomes, being (i) different species of African trypanosomes, (ii) Trypanosoma cruzi and (iii) Leishmania spp., using the six human sequences as queries, showed that the distribution of thiolases in human and each of the studied Trypanosomatidae is completely different. Only one of these isoforms, called SCP2-thiolase, was found in each of the Trypanosomatidae, whereas the TFE-thiolase was also found in T. cruzi and Leishmania spp., and the AB-thiolase only in T. cruzi. Each of the trypanosomatid thiolases clusters with its orthologues from other organisms in a phylogenetic analysis and shares with them the isoform-specific sequence fingerprints. The single T. brucei SCP2-thiolase has been expressed in Escherichia coli and characterized. It shows activity in both the degradative and synthetic directions. Transcripts of this thiolase were detected in both bloodstream- and procyclic-form trypanosomes, but the protein was found only in the procyclic form. The encoded protein has both a predicted N-terminal mitochondrial signal peptide and a C-terminal candidate type 1 peroxisomal-targeting signal for sorting it into glycosomes. However experimentally, only a mitochondrial localization was found for both procyclic trypanosomes grown with glucose and cells cultured with amino acids as an energy source. When the thiolase expression in procyclic cells was knocked down by RNA interference, no important change in growth rate occurred, irrespective of whether the cells were grown with or without glucose, indicating that the metabolic pathway(s) involving this enzyme is/are not essential for the parasite under either of these growth conditions.
AB - Thiolases are enzymes that remove an acetyl-coenzyme A group from acyl-CoA in the catabolic β-oxidation of fatty acids, or catalyse the reverse condensation reaction for anabolic processes such as the biosynthesis of sterols and ketone bodies. In humans, six homologous isoforms of thiolase have been described, differing from each other in sequence, oligomeric state, substrate specificity and subcellular localization. A bioinformatics analysis of parasite genomes, being (i) different species of African trypanosomes, (ii) Trypanosoma cruzi and (iii) Leishmania spp., using the six human sequences as queries, showed that the distribution of thiolases in human and each of the studied Trypanosomatidae is completely different. Only one of these isoforms, called SCP2-thiolase, was found in each of the Trypanosomatidae, whereas the TFE-thiolase was also found in T. cruzi and Leishmania spp., and the AB-thiolase only in T. cruzi. Each of the trypanosomatid thiolases clusters with its orthologues from other organisms in a phylogenetic analysis and shares with them the isoform-specific sequence fingerprints. The single T. brucei SCP2-thiolase has been expressed in Escherichia coli and characterized. It shows activity in both the degradative and synthetic directions. Transcripts of this thiolase were detected in both bloodstream- and procyclic-form trypanosomes, but the protein was found only in the procyclic form. The encoded protein has both a predicted N-terminal mitochondrial signal peptide and a C-terminal candidate type 1 peroxisomal-targeting signal for sorting it into glycosomes. However experimentally, only a mitochondrial localization was found for both procyclic trypanosomes grown with glucose and cells cultured with amino acids as an energy source. When the thiolase expression in procyclic cells was knocked down by RNA interference, no important change in growth rate occurred, irrespective of whether the cells were grown with or without glucose, indicating that the metabolic pathway(s) involving this enzyme is/are not essential for the parasite under either of these growth conditions.
KW - Isoforms
KW - Leishmania
KW - Metabolism
KW - Mitochondrion
KW - Phylogenetic analysis
KW - SCP2
KW - Thiolase
KW - Trypanosoma
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U2 - 10.1016/j.ijpara.2011.07.009
DO - 10.1016/j.ijpara.2011.07.009
M3 - Article
C2 - 21907205
AN - SCOPUS:80053386318
SN - 0020-7519
VL - 41
SP - 1273
EP - 1283
JO - International Journal for Parasitology
JF - International Journal for Parasitology
IS - 12
ER -