Probing for primary functions of prohibitin in Trypanosoma brucei

Týč, Jiří; Faktorová, Drahomíra; Kriegová, Eva; Jirků, Milan; Vávrová, Zuzana; Maslov, Dmitri; Lukeš, Julius

doi:10.1016/j.ijpara.2009.07.008

Cited by 25 publications

(13 citation statements)

References 47 publications

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“…Cell lysates corresponding to 5 × 10 6 procyclic cells per lane were separated on a 12% SDS/PAGE gel and blotted. The polyclonal rabbit antibodies against IscU, MRP2, GAP1, PHB1 and enolase were used at 1 : 1000, 1 : 1000, 1 : 1000, 1 : 1000 and 1 : 150 000, respectively [43–45]. The polyclonal chicken antibodies against Nfs were used at 1 : 500.…”

Section: Methodsmentioning

confidence: 99%

Functions and cellular localization of cysteine desulfurase and selenocysteine lyase in Trypanosoma brucei

et al. 2010

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Nfs‐like proteins have cysteine desulfurase (CysD) activity, which removes sulfur (S) from cysteine, and provides S for iron–sulfur cluster assembly and the thiolation of tRNAs. These proteins also have selenocysteine lyase activity in vitro, and cleave selenocysteine into alanine and elemental selenium (Se). It was shown previously that the Nfs‐like protein called Nfs from the parasitic protist Trypanosoma brucei is a genuine CysD. A second Nfs‐like protein is encoded in the nuclear genome of T. brucei. We called this protein selenocysteine lyase (SCL) because phylogenetic analysis reveals that it is monophyletic with known eukaryotic selenocysteine lyases. The Nfs protein is located in the mitochondrion, whereas the SCL protein seems to be present in the nucleus and cytoplasm. Unexpectedly, downregulation of either Nfs or SCL protein leads to a dramatic decrease in both CysD and selenocysteine lyase activities concurrently in the mitochondrion and the cytosolic fractions. Because loss of Nfs causes a growth phenotype but loss of SCL does not, we propose that Nfs can fully complement SCL, whereas SCL can only partially replace Nfs under our growth conditions. Structured digital abstract http://mint.bio.uniroma2.it/mint/search/interaction.do?interactionAc=MINT-7298305: NFS (uniprotkb:http://www.uniprot.org/uniprot/Q386Y7?format=text&ascii) and PHB1 (uniprotkb:http://www.uniprot.org/uniprot/Q57UX1?format=text&ascii) colocalize (http://www.ebi.ac.uk/ontology-lookup/?termId=MI:0403) by cosedimentation through density gradients (http://www.ebi.ac.uk/ontology-lookup/?termId=MI:0029) http://mint.bio.uniroma2.it/mint/search/interaction.do?interactionAc=MINT-7298357: SCL (uniprotkb:http://www.uniprot.org/uniprot/Q38DC4?format=text&ascii) and Enolase (uniprotkb:http://www.uniprot.org/uniprot/Q38BV6?format=text&ascii) colocalize (http://www.ebi.ac.uk/ontology-lookup/?termId=MI:0403) by cosedimentation through density gradients (http://www.ebi.ac.uk/ontology-lookup/?termId=MI:0029)

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Section: Methodsmentioning

confidence: 99%

Functions and cellular localization of cysteine desulfurase and selenocysteine lyase in Trypanosoma brucei

et al. 2010

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“…Plasma membrane localization of prohibitin has been reported in T. brucei (Broadhead et al, 2006;Bridges et al, 2008), a closely related species to Leishmania. A very recent report indicates a mitochondria linked function in Trypanosoma brucei (Tyc et al, 2009). Barring these few reports on identification, no literature is available on prohibitin function in the kinetoplastid parasites.…”

Section: Introductionmentioning

confidence: 99%

Leishmaniacell surface prohibitin: role in host-parasite interaction

Jain

Ghoshal

Mandal

et al. 2010

Cellular Microbiology

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SummaryProteins selectively upregulated in infective parasitic forms could be critical for disease pathogenesis. A mammalian prohibitin orthologue is upregulated in infective metacyclic promastigotes of Leishmania donovani, a parasite that causes visceral leishmaniasis. Leishmania donovani prohibitin shares 41% similarity with mammalian prohibitin and 95-100% within the genus. Prohibitin is concentrated at the surface of the flagellar and the aflagellar pole, the aflagellar pole being a region through which host-parasite interactions occur. Prohibitin is attached to the membrane through a GPI anchor. Overexpression of wild-type prohibitin increases protein surface density resulting in parasites with higher infectivity. However, parasites overexpressing a mutant prohibitin with an amino acid substitution at the GPI anchor site to prevent surface expression through GPI-link show lesser surface expression and lower infective abilities. Furthermore, the presence of anti-prohibitin antibodies during macrophage-Leishmania interaction in vitro reduces infection. The cognate binding partner for Leishmania prohibitin on the host cell appears to be macrophage surface HSP70, siRNA mediated downregulation of which abrogates the capability of the macrophage to bind to parasites. Leishmania prohibitin is able to generate a strong humoral response in visceral leishmaniasis patients. The above observations suggest that prohibitin plays an important role in events leading to Leishmania-host interaction.

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“…Proteins from total, cytosolic and mitochondrial fractions (10 µg/lane) were used for Western analysis as described above. The purity of fractions was assayed using antibodies against enolase and prohibitin [19], which are specific for cytosol and mitochondrion, respectively (Fig. 1C).…”

Section: Resultsmentioning

confidence: 99%

Futile import of tRNAs and proteins into the mitochondrion of Trypanosoma brucei evansi

Paris

Hashimi

Lun

et al. 2011

Molecular and Biochemical Parasitology

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Trypanosoma brucei brucei has two distinct developmental stages, the procyclic stage in the insect and the bloodstream stage in the mammalian host. The significance of each developmental stage is punctuated by specific changes in metabolism. In the insect, T. b. brucei is strictly dependent on mitochondrial function and thus respiration to generate the bulk of its ATP, whereas in the mammalian host it relies heavily on glycolysis. These observations have raised questions about the importance of mitochondrial function in the bloodstream. Peculiarly, akinetoplastic strains of Trypanosoma brucei evansi that lack mitochondrial DNA do exist in the wild and are developmentally locked in the glycolysis-dependent bloodstream stage. Using RNAi we show that two mitochondrion-imported proteins, mitochondrial RNA polymerase and guide RNA associated protein 1, are still imported into the nucleic acids-lacking organelle of T. b. evansi, making the need for these proteins futile. We also show that, like in the T. b. brucei procyclic stage, the mitochondria of both bloodstream stage of T. b. brucei and T. b. evansi import various tRNAs, including those that undergo thiolation. However, we were unable to detect mitochondrial thiolation in the akinetoplastic organelle. Taken together, these data suggest a lack of connection between nuclear and mitochondrial communication in strains of T. b. evansi that lost mitochondrial genome and that do not required an insect vector for survival.

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Probing for primary functions of prohibitin in Trypanosoma brucei

Cited by 25 publications

References 47 publications

Functions and cellular localization of cysteine desulfurase and selenocysteine lyase in Trypanosoma brucei

Functions and cellular localization of cysteine desulfurase and selenocysteine lyase in Trypanosoma brucei

Leishmaniacell surface prohibitin: role in host-parasite interaction

Futile import of tRNAs and proteins into the mitochondrion of Trypanosoma brucei evansi

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