The bacterial-like HslVU protease complex subunits are involved in the control of different cell cycle events in trypanosomatids

Mbang-Benet, Diane-Ethna; Sterkers, Yvon; Morelle, Christelle; Kebe, Ndeye-Mathy; Crobu, Lucien; Portalès, Pierre; Coux, Olivier; Hernandez, Jean‐François; Meghamla, Sabrina; Pagès, Michel; Bastien, Patrick

doi:10.1016/j.actatropica.2013.11.017

Cited by 11 publications

(17 citation statements)

References 37 publications

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“…Furthermore, results shown in this study argued against an association between HslV and the HslU proteins in L. donovani [ 32 ]. However, these findings have been questioned in a recent report, in which the mitochondrial localization of proteins HslU1, HslU2, and HslV in L. major procyclic promastigotes has been definitively established [ 33 ].…”

Section: Hsp100/clp Familymentioning

confidence: 99%

Molecular Chaperones ofLeishmania: Central Players in Many Stress-Related and -Unrelated Physiological Processes

Requena

Montalvo

Fraga

2015

BioMed Research International

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Molecular chaperones are key components in the maintenance of cellular homeostasis and survival, not only during stress but also under optimal growth conditions. Folding of nascent polypeptides is supported by molecular chaperones, which avoid the formation of aggregates by preventing nonspecific interactions and aid, when necessary, the translocation of proteins to their correct intracellular localization. Furthermore, when proteins are damaged, molecular chaperones may also facilitate their refolding or, in the case of irreparable proteins, their removal by the protein degradation machinery of the cell. During their digenetic lifestyle, Leishmania parasites encounter and adapt to harsh environmental conditions, such as nutrient deficiency, hypoxia, oxidative stress, changing pH, and shifts in temperature; all these factors are potential triggers of cellular stress. We summarize here our current knowledge on the main types of molecular chaperones in Leishmania and their functions. Among them, heat shock proteins play important roles in adaptation and survival of this parasite against temperature changes associated with its passage from the poikilothermic insect vector to the warm-blooded vertebrate host. The study of structural features and the function of chaperones in Leishmania biology is providing opportunities (and challenges) for drug discovery and improving of current treatments against leishmaniasis.

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Section: Hsp100/clp Familymentioning

confidence: 99%

Molecular Chaperones ofLeishmania: Central Players in Many Stress-Related and -Unrelated Physiological Processes

Requena

Montalvo

Fraga

2015

BioMed Research International

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“…Interestingly, from the studies on HslVU functions in these eukaryotes, it appears that, in contrast to its bacterial counterpart [21], the protease HslVU is essential for the survival of several parasites [22,23,24,25,26]. Indeed, it has been shown that both HslV and HslU1/U2 have important roles in mitochondrial DNA replication and cell cycle control in Trypanosoma brucei [22,26], and in transcription of genes encoded by the mitochondrial genome as well as cellular and mitochondrial growth in Plasmodium falciparum [23,25]. Thus, thanks to its essential functions in these dangerous parasites and its absence in humans, HslVU represents an attractive potential drug target to fight against deadly parasitic diseases.…”

Section: Introductionmentioning

confidence: 99%

“…Similar to T. brucei , L. major , which is the causative agent of cutaneous leishmaniasis, expresses together with HslV (LmHslV, UniProt ID Q4Q116) two isoforms of HslU, named LmHslU1 and LmHslU2 (UniProt IDs Q4QFH5 and Q4QI03, respectively). Our recent studies suggest that these two isoforms have specific roles [26], but whether they function as hetero- (U1/U2) or homo- (U1 and U2) complexes is presently not known.…”

Section: Introductionmentioning

confidence: 99%

The HslV Protease from Leishmania major and Its Activation by C-terminal HslU Peptides

Kebe

Samanta

Singh

et al. 2019

IJMS

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HslVU is an ATP-dependent proteolytic complex present in certain bacteria and in the mitochondrion of some primordial eukaryotes, including deadly parasites such as Leishmania. It is formed by the dodecameric protease HslV and the hexameric ATPase HslU, which binds via the C-terminal end of its subunits to HslV and activates it by a yet unclear allosteric mechanism. We undertook the characterization of HslV from Leishmania major (LmHslV), a trypanosomatid that expresses two isoforms for HslU, LmHslU1 and LmHslU2. Using a novel and sensitive peptide substrate, we found that LmHslV can be activated by peptides derived from the C-termini of both LmHslU1 and LmHslU2. Truncations, Ala- and D-scans of the C-terminal dodecapeptide of LmHslU2 (LmC12-U2) showed that five out of the six C-terminal residues of LmHslU2 are essential for binding to and activating HslV. Peptide cyclisation with a lactam bridge allowed shortening of the peptide without loss of potency. Finally, we found that dodecapeptides derived from HslU of other parasites and bacteria are able to activate LmHslV with similar or even higher efficiency. Importantly, using electron microscopy approaches, we observed that the activation of LmHslV was accompanied by a large conformational remodeling, which represents a yet unidentified layer of control of HslV activation.

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“…Furthermore, we found down regulation of several proteasome subunits that are known to be linked with cell cycle regulation in T. brucei (42). Particularly, the mitochondrial heat shock locus ATPase (HslVU) complex, known to play roles in kDNA replication/segregation (43,44), were downregulated >4-fold (pvalue <0.005) in TbTim50 KD cells (Table 1). We found that several subunits of the ATP synthase (complex V) complex were downregulated, which could be due to loss of CL or vice versa.…”

Section: Global Proteomics Analysis Revealed Downregulation Of Certain Cellular Functions Due Tomentioning

confidence: 90%

“…From our proteomic analysis we observed that mitochondrial HsIVU subunits were consistently downregulated >4-fold in all biological replicates (Table 1). HslVU is a prokaryotic proteasome complex found in mitochondria in certain eukaryotic species, including trypanosomatids (43)(44)(45)(46). T. brucei and related parasites thus have both mitochondrial HslVU and cytosolic 26S proteasome complexes.…”

Section: Global Proteomics Analysis Revealed Downregulation Of Certain Cellular Functions Due Tomentioning

confidence: 99%

Trypanosoma bruceiTim50 Plays a Critical Role in Cell Cycle Regulation and Parasite Infectivity

Tripathi

Cooley

et al. 2021

Preprint

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Tim50 is a receptor subunit of the preprotein-translocase of the mitochondrial inner membrane, TIM23. Trypanosoma brucei, the infective agent for African trypanosomiasis, possesses a homologue of Tim50 (TbTim50) with a pair of characteristic DXDX(T/V) phosphatase signature motifs. Here, we demonstrated that besides its protein phosphatase activity, the recombinant TbTim50 binds and hydrolyzes phosphatidic acid in a concentration-dependent manner. In silico structural homology models identify the putative binding interfaces that may accommodate different phospho-substrates. Interestingly, TbTim50 depletion in the bloodstream form (BF) of T. brucei reduced cardiolipin (CL) levels and decreased mitochondrial membrane potential (ΔΨ). TbTim50 knockdown (KD) also reduced the population of G2 phase and increased G1 phase; thus, BF cell growth was reduced. Confocal and electron microscopy revealed a defect in regulation of kinetoplast (kDNA) replication due to TbTim50 KD. Depletion of TbTim50 increased the levels of AMPK phosphorylation, and parasite morphology was changed to stumpy-like with upregulation of few stumpy marker gene expressions. Importantly, we observed that TbTim50-depleted parasites were unable to establish infection in mice and rats. Proteomics analysis showed reductions of the translation factors, flagellar transport proteins, and many proteasomal subunits, including the mitochondrial HslVU that is known to play a role in kDNA replication. Reduction of the level of HslV in TbTim50 KD cells was further validated by immunoblot analysis. Altogether, our results showed that TbTim50 is essential for mitochondrial function, regulation of kDNA replication, and cell cycle in the BF. Therefore, TbTim50 is an important target for structure-based drug design to combat African trypanosomiasis.ImportanceAfrican trypanosomiasis, a neglected tropical disease caused by parasitic protozoan Trypanosoma brucei, is transmitted by the tsetse fly prevalent in sub-Saharan Africa. During its digenetic life cycle, T. brucei undergoes multiple developmental changes to adapt in different environments. T. brucei BF, dwelling in mammalian blood, generates ATP from glycolysis and hydrolyzes ATP in mitochondria for inner membrane potential. We found that TbTim50, a HAD-family phosphatase, is critical for T. brucei BF survival in vitro and in vivo. Depletion of TbTim50 in BF reduced CL levels and mitochondrial ΔΨ and caused a detrimental effect on many cellular functions. Cells accumulated in G1-S phase, and kinetoplast was over-replicated due to depletion of mitochondrial proteasomes, HslVU, a master-regulator of kDNA replication. Cell growth inhibition was accompanied by changes in morphology, AMPK phosphorylation, and upregulation of stumpy-specific gene expression. TbTim50 is essential for T. brucei survival and an important T. brucei therapeutic target.

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The bacterial-like HslVU protease complex subunits are involved in the control of different cell cycle events in trypanosomatids

Cited by 11 publications

References 37 publications

Molecular Chaperones ofLeishmania: Central Players in Many Stress-Related and -Unrelated Physiological Processes

Molecular Chaperones ofLeishmania: Central Players in Many Stress-Related and -Unrelated Physiological Processes

The HslV Protease from Leishmania major and Its Activation by C-terminal HslU Peptides

Trypanosoma bruceiTim50 Plays a Critical Role in Cell Cycle Regulation and Parasite Infectivity

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