scholarly journals Qualitative difference of mitochondrial subproteoms of brain RPN10- and RPN13-binding proteins

2020 ◽  
Vol 66 (2) ◽  
pp. 138-144
Author(s):  
O.A. Buneeva ◽  
A.T. Kopylov ◽  
A.E. Medvedev
Keyword(s):  
Binding Proteins ◽  
Qualitative Difference ◽  
High Specificity ◽  
Ubiquitin Proteasome System ◽  
Good Evidence ◽  
Mitochondrial Proteins ◽  
Regulatory Subunit ◽  
Target Proteins ◽  
Affinity Ligand ◽  
Subsequent Degradation

Good evidence exists that the ubiquitin-proteasome system (UPS) plays an important role in degradation of mitochondrial proteins and membrane proteins associated with mitochondria (MAM proteins). Mitochondria contain all components of the ubiquitin-conjugating system, which are necessary for the attachment of ubiquitin molecules to target proteins, subjected to subsequent degradation in proteasomes. An important stage in the delivery of proteins for proteolytic degradation in proteasomes is their interaction with ubiquitin receptors located on the regulatory subunit (19S) of the proteasome: the Rpn10 or Rpn13 subunit. These subunits make basically the same contribution to the subsequent translocation of target proteins to the core part of the proteasome. A comparative study of mouse brain mitochondrial subproteomes bound to Rpn10 and Rpn13 subunits revealed a high specificity of the repertoire of Rpn10 and Rpn13-binding proteins. Moreover, proteins, for which mitochondrial localization or association with mitochondrial membranes was previously shown, prevailed in the case of using the Rpn13 subunit as an affinity ligand (Rpn13-binding proteins). This suggests that Rpn10 and Rpn13 play different roles in the degradation of mitochondrial proteins and MAM.

Changes in the mitochondrial subproteome of mouse brain Rpn13-binding proteins induced by the neurotoxin MPTP and the neuroprotector isatin

2021 ◽  
Vol 67 (1) ◽  
pp. 51-65
Author(s):  
O.A. Buneeva ◽  
A.T. Kopylov ◽  
O.V. Gnedenko ◽  
M.V. Medvedeva ◽  
I.G. Kapitsa ◽  
...  
Keyword(s):  
Mouse Brain ◽  
Binding Proteins ◽  
Functional Group ◽  
Neuroprotective Effect ◽  
Ubiquitin Proteasome System ◽  
Mitochondrial Proteins ◽  
Proteomic Profiling ◽  
Metabolism Regulation ◽  
Ubiquitin Proteasome ◽  
Biomedical Chemistry

Mitochondrial dysfunction and ubiquitin-proteasome system (UPS) failure contribute significantly to the development of Parkinson's disease (PD). The proteasome subunit Rpn13 located on the regulatory (19S) subparticle play an important role in the delivery of proteins, subjected to degradation, to the proteolytic (20S) part of proteasome. We have previously found several brain mitochondrial proteins specifically bound to Rpn13 (Buneeva et al. (2020) Biochemistry (Moscow), Supplement Series B: Biomedical Chemistry, 14, 297-305). In this study we have investigated the effect of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and the neuroprotector isatin on the mitochondrial subproteome of Rpn13-binding proteins of the mouse brain. Administration of MPTP (30 mg/kg) to animals caused movement disorders typical of PD, while pretreatment with isatin (100 mg/kg, 30 min before MPTP) reduced their severity. At the same time, the injection of MPTP, isatin, or their combination (isatin + MPTP) had a significant impact on the total number and the composition of Rpn13-binding proteins. The injection of MPTP decreased the total number of Rpn13-binding proteins in comparison with control, and the injection of isatin prior to MPTP or without MPTP caused an essential increase in the number of Rpn13-binding proteins, mainly of the functional group of proteins participating in the protein metabolism regulation, gene expression, and differentiation. Selected biosensor validation confirmed the interaction of Rpn13 subunit of proteasome with some proteins (glyceraldehyde-3-phosphate dehydrogenase, pyruvate kinase, histones H2A and H2B) revealed while proteomic profiling. The results obtained testify that under the conditions of experimental MPTP-induced parkinsonism the neuroprotective effect of isatin may be aimed at the interaction of mitochondria with the components of UPS.

Human Epididymis Protein 4 Quantification and Interaction Network Analysis in Seminal Plasma

2019 ◽  
Vol 26 (6) ◽  
pp. 458-465
Author(s):  
Krishna Kant ◽  
Anil K. Tomar ◽  
Pankaj Sharma ◽  
Bishwajit Kundu ◽  
Sarman Singh ◽  
...  
Keyword(s):  
Seminal Plasma ◽  
Binding Proteins ◽  
Interaction Network ◽  
Prostatic Acid Phosphatase ◽  
Regulatory Subunit ◽  
Plasma Samples ◽  
Human Seminal Plasma ◽  
Human Epididymis Protein 4 ◽  
Human Epididymis ◽  
Core Proteins

Background: A well-known tissue marker of ovarian cancer, Human Epididymis protein 4 (HE4) is the member of whey acidic four-disulfide core proteins family. Purified from human seminal plasma and characterized as a cross-class protease inhibitor, HE4 was proposed to shield spermatozoa against proteolytic factors. However, its exact biological function is unknown. Proteins usually function in conjunction with other proteins in the system and thus, identification and analysis of protein networks become essential to decode protein functions. Objective: This study was performed to explore possible role(s) of HE4 in reproductive physiology via identification of its interactome in human seminal plasma. Methods: HE4 binding proteins were identified through co-immunoprecipitation and MALDITOF/ MS analysis. Also, HE4 was quantified by ELISA in fertile and infertile human seminal plasma samples. Results: Ten HE4 binding proteins were identified, viz. protein phosphatase 1 regulatory subunit 21, protein kinase CLK3, Ankyrin repeat domain-containing protein36A, prostatic acid phosphatase, KIF5C, Spectrin repeat containing, nuclear envelope 1, isoform CRAf, tropomyosin 4, vezatin, utrophin and fibronectin1. This interaction network suggests that HE4 plays multiple roles, specifically in capacitation, sperm motility and maturation. Further, HE4 concentration in human seminal plasma samples was determined by Elisa. Higher HE4 expression in normozoospermia compared to azoospermia and asthenozoospermia affirms its importance in fertilization. Conclusion: Based on identified interactome, it is plausible that HE4 plays a crucial role in fertilization, specifically in sperm maturation, motility and capacitation.

Shall we really say goodbye to first rank symptoms?

2016 ◽  
Vol 37 ◽  
pp. 8-13 ◽  
Author(s):  
A. Heinz ◽  
M. Voss ◽  
S.M. Lawrie ◽  
A. Mishara ◽  
M. Bauer ◽  
...  
Keyword(s):  
Meta Analysis ◽  
High Specificity ◽  
Good Evidence ◽  
Diagnostic Process ◽  
Future Research ◽  
Phenotypic Trait ◽  
Warning Sign ◽  
Systematic Assessment ◽  
Specific Care ◽  
First Rank Symptoms

AbstractBackgroundFirst rank symptoms (FRS) of schizophrenia have been used for decades for diagnostic purposes. In the new version of the DSM-5, the American Psychiatric Association (APA) has abolished any further reference to FRS of schizophrenia and treats them like any other “criterion A” symptom (e.g. any kind of hallucination or delusion) with regard to their diagnostic implication. The ICD-10 is currently under revision and may follow suit. In this review, we discuss central points of criticism that are directed against the continuous use of first rank symptoms (FRS) to diagnose schizophrenia.MethodsWe describe the specific circumstances in which Schneider articulated his approach to schizophrenia diagnosis and discuss the relevance of his approach today. Further, we discuss anthropological and phenomenological aspects of FRS and highlight the importance of self-disorder (as part of FRS) for the diagnosis of schizophrenia. Finally, we will conclude by suggesting that the theory and rationale behind the definition of FRS is still important for psychopathological as well as neurobiological approaches today.ResultsResults of a pivotal meta-analysis and other studies show relatively poor sensitivity, yet relatively high specificity for FRS as diagnostic marker for schizophrenia. Several methodological issues impede a systematic assessment of the usefulness of FRS in the diagnosis of schizophrenia. However, there is good evidence that FRS may still be useful to differentiate schizophrenia from somatic causes of psychotic states. This may be particularly important in countries or situations with little access to other diagnostic tests. FRS may thus still represent a useful aid for clinicians in the diagnostic process.ConclusionIn conclusion, we suggest to continue a tradition of careful clinical observation and fine-grained psychopathological assessment, including a focus on symptoms regarding self-disorders, which reflects a key aspect of psychosis. We suggest that the importance of FRS may indeed be scaled down to a degree that the occurrence of a single FRS alone should not suffice to diagnose schizophrenia, but, on the other hand, absence of FRS should be regarded as a warning sign that the diagnosis of schizophrenia or schizoaffective disorder is not warranted and requires specific care to rule out other causes, particularly neurological and other somatic disorders. With respect to the current stage of the development of ICD-11, we appreciate the fact that self-disorders are explicitly mentioned (and distinguished from delusions) in the list of mandatory symptoms but still feel that delusional perceptions and complex hallucinations as defined by Schneider should be distinguished from delusions or hallucinations of “any kind”. Finally, we encourage future research to explore the psychopathological context and the neurobiological correlates of self-disorders as a potential phenotypic trait marker of schizophrenia.

scholarly journals The interactome of 2-Cys peroxiredoxins in Plasmodium falciparum

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Christina Brandstaedter ◽  
Claire Delahunty ◽  
Susanne Schipper ◽  
Stefan Rahlfs ◽  
John R. Yates ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Active Site ◽  
Cellular Protein ◽  
Mitochondrial Proteins ◽  
Target Proteins ◽  
Cellular Processes ◽  
Mixed Disulfide ◽  
Functional Analyses ◽  
Cell Proteome ◽  
Active Site Mutants

Abstract Peroxiredoxins (Prxs) are crucially involved in maintaining intracellular H2O2 homeostasis via their peroxidase activity. However, more recently, this class of proteins was found to also transmit oxidizing equivalents to selected downstream proteins, which suggests an important function of Prxs in the regulation of cellular protein redox relays. Using a pull-down assay based on mixed disulfide fishing, we characterized the thiol-dependent interactome of cytosolic Prx1a and mitochondrial Prx1m from the apicomplexan malaria parasite Plasmodium falciparum (Pf). Here, 127 cytosolic and 20 mitochondrial proteins that are components of essential cellular processes were found to interact with PfPrx1a and PfPrx1m, respectively. Notably, our data obtained with active-site mutants suggests that reducing equivalents might also be transferred from Prxs to target proteins. Initial functional analyses indicated that the interaction with Prx can strongly impact the activity of target proteins. The results provide initial insights into the interactome of Prxs at the level of a eukaryotic whole cell proteome. Furthermore, they contribute to our understanding of redox regulatory principles and thiol-dependent redox relays of Prxs in subcellular compartments.

scholarly journals Rotavirus NSP1 Associates with Components of the Cullin RING Ligase Family of E3 Ubiquitin Ligases

2016 ◽  
Vol 90 (13) ◽  
pp. 6036-6048 ◽  
Author(s):  
Lindy M. Lutz ◽  
Chandler R. Pace ◽  
Michelle M. Arnold
Keyword(s):  
Mass Spectrometry ◽  
Ubiquitin Ligase ◽  
Nonstructural Protein ◽  
Ubiquitin Proteasome System ◽  
Scaffolding Proteins ◽  
Target Proteins ◽  
Rotavirus A ◽  
Ubiquitin Proteasome ◽  
Infected Cells

ABSTRACTThe rotavirus nonstructural protein NSP1 acts as an antagonist of the host antiviral response by inducing degradation of key proteins required to activate interferon (IFN) production. Protein degradation induced by NSP1 is dependent on the proteasome, and the presence of a RING domain near the N terminus has led to the hypothesis that NSP1 is an E3 ubiquitin ligase. To examine this hypothesis, pulldown assays were performed, followed by mass spectrometry to identify components of the host ubiquitination machinery that associate with NSP1. Multiple components of cullin RING ligases (CRLs), which are essential multisubunit ubiquitination complexes, were identified in association with NSP1. The mass spectrometry was validated in both transfected and infected cells to show that the NSP1 proteins from different strains of rotavirus associated with key components of CRL complexes, most notably the cullin scaffolding proteins Cul3 and Cul1.In vitrobinding assays using purified proteins confirmed that NSP1 specifically interacted with Cul3 and that the N-terminal region of Cul3 was responsible for binding to NSP1. To test if NSP1 used CRL3 to induce degradation of the target protein IRF3 or β-TrCP, Cul3 levels were knocked down using a small interfering RNA (siRNA) approach. Unexpectedly, loss of Cul3 did not rescue IRF3 or β-TrCP from degradation in infected cells. The results indicate that, rather than actively using CRL complexes to induce degradation of target proteins required for IFN production, NSP1 may use cullin-containing complexes to prevent another cellular activity.IMPORTANCEThe ubiquitin-proteasome pathway plays an important regulatory role in numerous cellular functions, and many viruses have evolved mechanisms to exploit or manipulate this pathway to enhance replication and spread. Rotavirus, a major cause of severe gastroenteritis in young children that causes approximately 420,000 deaths worldwide each year, utilizes the ubiquitin-proteasome system to subvert the host innate immune response by inducing the degradation of key components required for the production of interferon (IFN). Here, we show that NSP1 proteins from different rotavirus strains associate with the scaffolding proteins Cul1 and Cul3 of CRL ubiquitin ligase complexes. Nonetheless, knockdown of Cul1 and Cul3 suggests that NSP1 induces the degradation of some target proteins independently of its association with CRL complexes, stressing a need to further investigate the mechanistic details of how NSP1 subverts the host IFN response.

Sign in / Sign up

Export Citation Format

Share Document