A Single Tim Translocase in the Mitosomes of Giardia intestinalis Illustrates Convergence of Protein Import Machines in Anaerobic Eukaryotes

Pyrihová, Eva; Motyčková, Alžběta; Voleman, Luboš; Wandyszewska, Natalia; Fišer, Radovan; Seydlová, Gabriela; Roger, Andrew J.; Kolísko, Martin; Doležal, Pavel

doi:10.1093/gbe/evy215

Cited by 43 publications

(46 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, it is extremely difficult to paint a clearer picture of the import process occurring in Entamoeba mitosomes. In G. intestinalis , a metamonad-specific hidden Markov model-based search yielded a highly divergent homolog of the pore-forming Tim17, which interacts with Gi Tim44, a tethering molecule linking the Tim and Pam complexes [ 54 ]. Similar to Giardia , it would not be surprising if future studies reveal a minimalist mechanism of protein targeting and import in this relic mitochondria of Entamoeba that is accompanied by components unique to its genus.…”

Section: Discussionmentioning

confidence: 99%

Import of Entamoeba histolytica Mitosomal ATP Sulfurylase Relies on Internal Targeting Sequences

et al. 2020

View full text Add to dashboard Cite

Mitochondrial matrix proteins synthesized in the cytosol often contain amino (N)-terminal targeting sequences (NTSs), or alternately internal targeting sequences (ITSs), which enable them to be properly translocated to the organelle. Such sequences are also required for proteins targeted to mitochondrion-related organelles (MROs) that are present in a few species of anaerobic eukaryotes. Similar to other MROs, the mitosomes of the human intestinal parasite Entamoeba histolytica are highly degenerate, because a majority of the components involved in various processes occurring in the canonical mitochondria are either missing or modified. As of yet, sulfate activation continues to be the only identified role of the relic mitochondria of Entamoeba. Mitosomes influence the parasitic nature of E. histolytica, as the downstream cytosolic products of sulfate activation have been reported to be essential in proliferation and encystation. Here, we investigated the position of the targeting sequence of one of the mitosomal matrix enzymes involved in the sulfate activation pathway, ATP sulfurylase (AS). We confirmed by immunofluorescence assay and subcellular fractionation that hemagluttinin (HA)-tagged EhAS was targeted to mitosomes. However, its ortholog in the δ-proteobacterium Desulfovibrio vulgaris, expressed as DvAS-HA in amoebic trophozoites, indicated cytosolic localization, suggesting a lack of recognizable mitosome targeting sequence in this protein. By expressing chimeric proteins containing swapped sequences between EhAS and DvAS in amoebic cells, we identified the ITSs responsible for mitosome targeting of EhAS. This observation is similar to other parasitic protozoans that harbor MROs, suggesting a convergent feature among various MROs in favoring ITS for the recognition and translocation of targeted proteins.

show abstract

Section: Discussionmentioning

confidence: 99%

Import of Entamoeba histolytica Mitosomal ATP Sulfurylase Relies on Internal Targeting Sequences

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Unlike trypanosomatids, other members of the eukaryotic supergroup Excavata, including Trichomonas vaginalis (T. vaginalis) and Naegleria gruberi, possess multiple copies of the Tim17/22/23 family proteins [32,34] (Table 3). Recently, a Tim17-like protein also has been identified in Giardia mitosomes [92]. The Giardia Tim17 showed a stronger similarity to Tim17 than Tim23 and to Tim22 in other eukaryotes [34].…”

Section: Prevalence Of Tim17 and Tim17 Homologues Among Eukaryotesmentioning

confidence: 99%

“…However, TbTim17 possesses the signature PRAT motif within TM2-loop2-TM3 region and multiple GXXXG motifs within the TMs, as discussed in the later section [73] (Figure 2). The most divergent Tim17 sequence has been found in Giardia (Gi), which was recognized by specialized Hidden Markov Model [92]. In spite of this divergence, GiTim17 has the conserved arginine residue for interaction with Tim44 and also has one GXXXG motif in one of the predicted TMs at the C-terminal domain [92].…”

Section: Tim17 Structurementioning

confidence: 99%

Tim17 Updates: A Comprehensive Review of an Ancient Mitochondrial Protein Translocator

et al. 2020

View full text Add to dashboard Cite

The translocases of the mitochondrial outer and inner membranes, the TOM and TIMs, import hundreds of nucleus-encoded proteins into mitochondria. TOM and TIMs are multi-subunit protein complexes that work in cooperation with other complexes to import proteins in different sub-mitochondrial destinations. The overall architecture of these protein complexes is conserved among yeast/fungi, animals, and plants. Recent studies have revealed unique characteristics of this machinery, particularly in the eukaryotic supergroup Excavata. Despite multiple differences, homologues of Tim17, an essential component of one of the TIM complexes and a member of the Tim17/Tim22/Tim23 family, have been found in all eukaryotes. Here, we review the structure and function of Tim17 and Tim17-containing protein complexes in different eukaryotes, and then compare them to the single homologue of this protein found in Trypanosoma brucei, a unicellular parasitic protozoan.

show abstract

“…Additional file 9: Table S6 in lists all primers used in this study. Escherichia coli biotin ligase (BirA) in pTG vector was used for the co-expression with GiPuf4 [80]. G. intestinalis transfection was performed as previously described [40].…”

Section: Cell Culture Cloning and Transfectionmentioning

confidence: 99%

The evolution of the Puf superfamily of proteins across the tree of eukaryotes

et al. 2020

Self Cite

View full text Add to dashboard Cite

Background: Eukaryotic gene expression is controlled by a number of RNA-binding proteins (RBP), such as the proteins from the Puf (Pumilio and FBF) superfamily (PufSF). These proteins bind to RNA via multiple Puf repeat domains, each of which specifically recognizes a single RNA base. Recently, three diversified PufSF proteins have been described in model organisms, each of which is responsible for the maturation of ribosomal RNA or the translational regulation of mRNAs; however, less is known about the role of these proteins across eukaryotic diversity. Results: Here, we investigated the distribution and function of PufSF RBPs in the tree of eukaryotes. We determined that the following PufSF proteins are universally conserved across eukaryotes and can be broadly classified into three groups: (i) Nop9 orthologues, which participate in the nucleolar processing of immature 18S rRNA; (ii) 'classical' Pufs, which control the translation of mRNA; and (iii) PUM3 orthologues, which are involved in the maturation of 7S rRNA. In nearly all eukaryotes, the rRNA maturation proteins, Nop9 and PUM3, are retained as a single copy, while mRNA effectors ('classical' Pufs) underwent multiple lineage-specific expansions. We propose that the variation in number of 'classical' Pufs relates to the size of the transcriptome and thus the potential mRNA targets. We further distinguished full set of PufSF proteins in divergent metamonad Giardia intestinalis and initiated their cellular and biochemical characterization. Conclusions: Our data suggest that the last eukaryotic common ancestor (LECA) already contained all three types of PufSF proteins and that 'classical' Pufs then underwent lineage-specific expansions.

show abstract

A Single Tim Translocase in the Mitosomes of Giardia intestinalis Illustrates Convergence of Protein Import Machines in Anaerobic Eukaryotes

Cited by 43 publications

References 53 publications

Import of Entamoeba histolytica Mitosomal ATP Sulfurylase Relies on Internal Targeting Sequences

Import of Entamoeba histolytica Mitosomal ATP Sulfurylase Relies on Internal Targeting Sequences

Tim17 Updates: A Comprehensive Review of an Ancient Mitochondrial Protein Translocator

The evolution of the Puf superfamily of proteins across the tree of eukaryotes

Contact Info

Product

Resources

About