Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Role of TbTim20 in mitochondrial protein import in trypanosomes – TbTim15 CoIPs

ABSTRACT: Protein import across the mitochondrial inner membrane typically depends on two protein translocases of the inner membrane (TIM) complexes and the membrane potential. The protozoan parasite Trypanosoma brucei, however, has a single, divergent TIM complex. Unlike other trypanosomal TIM subunits, TbTim20 is neither essential for normal growth of insect nor bloodstream forms of T. brucei, leaving its role uncertain. Specific mutations in the γ-subunit of the F1FO-ATPase, such as γL262P, permit bloodstream form trypanosomes to grow without mitochondrial DNA (kinetoplast or kDNA). Here we show that RNAi-mediated depletion of TbTim20 inhibits growth of this cell line, but only if it lacks the kDNA. Titration of mitochondrial uncouplers and direct membrane potential measurements reveal that TbTim20 becomes more critical as the membrane potential decreases across all tested lines. Proteomic analysis of the uninduced and induced γL262P TbTim20-RNAi cell line, which lacks kDNA and exhibits the lowest membrane potential, shows depletion of a subset of imported proteins. This subset includes ATPase subunits, explaining why TbTim20-silenced cell lines become more sensitive to uncouplers. Thus, we propose that TbTim20 supports import of a subset of proteins whose import is hypersensitive to a low membrane potential.

INSTRUMENT(S):

ORGANISM(S): Trypanosoma Brucei

SUBMITTER: Julian Bender

LAB HEAD: Bettina Warscheid

PROVIDER: PXD061391 | Pride | 2025-10-27

REPOSITORIES: Pride

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
	MaxQtxtTbTim15SILACCoIPs.zip	Other
	QEplus033232.raw	Raw
	QEplus033234.raw	Raw
	QEplus033237.raw	Raw
	QEplus033239.raw	Raw

Items per page:

1 - 5 of 5

Similar Datasets

Role of TbTim20 in mitochondrial protein import in trypanosomes – TbTim20 CoIPs

Project description:Protein import across the mitochondrial inner membrane typically depends on two protein translocases of the inner membrane (TIM) complexes and the membrane potential. The protozoan parasite Trypanosoma brucei, however, has a single, divergent TIM complex. Unlike other trypanosomal TIM subunits, TbTim20 is neither essential for normal growth of insect nor bloodstream forms of T. brucei, leaving its role uncertain. Specific mutations in the γ-subunit of the F1FO-ATPase, such as γL262P, permit bloodstream form trypanosomes to grow without mitochondrial DNA (kinetoplast or kDNA). Here we show that RNAi-mediated depletion of TbTim20 inhibits growth of this cell line, but only if it lacks the kDNA. Titration of mitochondrial uncouplers and direct membrane potential measurements reveal that TbTim20 becomes more critical as the membrane potential decreases across all tested lines. Proteomic analysis of the uninduced and induced γL262P TbTim20-RNAi cell line, which lacks kDNA and exhibits the lowest membrane potential, shows depletion of a subset of imported proteins. This subset includes ATPase subunits, explaining why TbTim20-silenced cell lines become more sensitive to uncouplers. Thus, we propose that TbTim20 supports import of a subset of proteins whose import is hypersensitive to a low membrane potential.

2025-10-27 | PXD061390 | Pride

Role of TbTim20 in mitochondrial protein import in trypanosomes – TbTim20 RNAi data

2025-10-27 | PXD061395 | Pride

Trypanosomal Pam18/Pam16 and maxicircle replication – TbPam16 CoIPs

Project description:Protein import and genome replication are essential processes for mitochondrial biogenesis and propagation. The J-domain proteins Pam16 and Pam18 regulate the presequence translocase of the mitochondrial inner membrane. In the protozoan Trypanosoma brucei, their counterparts are TbPam16 and TbPam18, which are essential for the procyclic form of the parasite, though not involved in mitochondrial protein import. Here, we show that during evolution, the two proteins have been repurposed to regulate the replication of maxicircles within the intricate kDNA network, the most complex mitochondrial genome known. TbPam18 and TbPam16 have inactive J-domains suggesting a function independent of heat shock proteins. However, their single transmembrane domain is essential for function. Pulldown of TbPam16 identifies a putative client protein, termed MaRF11, the depletion of which causes the selective loss of maxicircles, akin to the effects observed for TbPam18 and TbPam16. The level of MaRF11 is controlled by the mitochondrial proteasome. Thus, we propose a model for a membrane-bound regulatory circuit that controls maxicircle replication in response to an unknown nuclear signal. This model posits that MaRF11 directly mediates maxicircle replication, that its activity is regulated by the mitochondrial proteasome that its level is controlled by proteasomal digested that it is protected from degradation by binding to the TbPam18/TbPam16 dimer.

2024-07-20 | PXD046849 | Pride

Beyond a linear structure: The Tubular of the Tripartite Attachment Complex and the Functional Role of TAC53

Project description:The tripartite attachment complex (TAC) is essential for mitochondrial DNA (kDNA) segregation in Trypanosoma brucei, providing a physical link between the flagellar basal body and the mitochondrial genome. Although the TAC's hierarchical assembly and linear organization have been extensively studied, much remains to be discovered regarding its complete architecture and composition – for instance, our identification of a new TAC component underscores these knowledge gaps. Here, we use a combination of proteomics, RNA interference (RNAi), and Ultrastructure Expansion Microscopy (U-ExM) to characterize the TAC at high resolution and identify a novel component, TAC53 (Tb927.2.6100). Depletion of TAC53 in both procyclic and bloodstream forms results in kDNA missegregation and loss, a characteristic feature of TAC dysfunction. TAC53 localizes to the kDNA in a cell cycle–dependent manner and represents the most kDNA-proximal TAC component identified to date. U-ExM reveals a previously unrecognized tubular architecture of the TAC, with two distinct TAC structures per kDNA disc, suggesting a mechanism for precise kDNA alignment and segregation. Moreover, immunoprecipitation and imaging analyses indicate that TAC53 interacts with known TAC-associated proteins HMG44, KAP68, and KAP3, forming a network at the TAC-kDNA interface. These findings redefine our understanding of TAC architecture and function and identify TAC53 as a key structural component anchoring the mitochondrial genome in T. brucei.

2025-08-11 | PXD062506 | Pride

A hybrid TIM complex mediates protein import into hydrogenosomes of Trichomonas vaginalis

Project description:Hydrogenosomes are a specific type of mitochondria that have adapted for life under anaerobiosis. Limited availability of oxygen has resulted in the loss of the membrane- associated respiratory chain, and consequently in the generation of minimal inner membrane potential (), and inefficient ATP synthesis via substrate-level phosphorylation. The changes in energy metabolism are directly linked with the organelle biogenesis. In mitochondria, proteins are imported across the outer membrane via the Translocase of the Outer Membrane (TOM complex), while two Translocases of the Inner Membrane, TIM22, and TIM23, facilitate import to the inner membrane and matrix. TIM23-mediated steps are entirely dependent on and ATP hydrolysis, while TIM22 requires only . The character of the hydrogenosomal inner membrane translocase and the mechanism of translocation is currently unknown.

2024-06-16 | PXD047649 | Pride

The non-canonical mitochondrial inner membrane presequence translocase of trypanosomatids contains two essential rhomboid-like proteins

Project description:Mitochondrial protein import is essential for all eukaryotes. Here we show that the early diverging eukaryote Trypanosoma brucei has a non-canonical inner membrane (IM) protein translocation machinery. Besides TbTim17, the single member of the Tim17/22/23 family in trypanosomes, the presequence translocase contains nine subunits that co-purify in reciprocal immunoprecipitations and with a presequence-containing substrate that is trapped in the translocation channel. Two of the newly discovered subunits are rhomboid-like proteins, which are essential for growth and mitochondrial protein import. Rhomboid-like proteins were proposed to form the protein translocation pore of the ER-associated degradation system, suggesting that they may contribute to pore formation in the presequence translocase of T. brucei. Pulldown of import-arrested mitochondrial carrier protein shows that the carrier translocase shares eight subunits with the presequence translocase. This indicates that T. brucei may have a single IM translocase that with compositional variations mediates import of presequence-containing and carrier proteins.

2016-12-20 | PXD005484 | Pride

Bound chromatin analysis of mouse Zfp92 in MIN6 cells

Project description:Zfp92, a repressive KRAB domain-containing zinc-finger protein, was identified by Gene Co-expression Network analysis to be an interesting candidate gene involved in endocrine specification and maturation. We examined the role of Zfp92, a KRAB-ZFP that is highly expressed in pancreatic islets of adult mice, by analyzing global Zfp92 knockout (KO) mice. Adult Zfp92 KO animals exhibited only mild changes in glucose homeostasis and no change in islet structure, although, male KO mice exhibited decreased growth, and female KO mice exhibited increased body fat accumulation on a high fat diet. We found that Zfp92 regulates a subset of transposable elements as well as Mafb, a transcription factor involved in islet development.

2023-03-17 | E-MTAB-12576 | biostudies-arrayexpress

Trypanosomal Pam18/Pam16 and maxicircle replication – MaRF11 SILAC RNAi

2024-07-20 | PXD053251 | Pride

Trypanosomal Pam18/Pam16 and maxicircle replication – TbPam18 SILAC RNAiTrypanosomal Pam18/Pam16 and maxicircle replication – TbPam18 SILAC RNAi

2024-07-20 | PXD046845 | Pride

Trypanosomal Pam18/Pam16 and maxicircle replication – TbPam16 SILAC RNAi

2024-07-20 | PXD046840 | Pride