scholarly journals Knock-Out of ACBD3 Leads to Dispersed Golgi Structure, but Unaffected Mitochondrial Functions in HEK293 and HeLa Cells

2021 ◽  
Vol 22 (14) ◽  
pp. 7270
Author(s):  
Tereza Daňhelovská ◽  
Lucie Zdražilová ◽  
Hana Štufková ◽  
Marie Vanišová ◽  
Nikol Volfová ◽  
...  
Keyword(s):  
Hela Cells ◽  
Protein Biosynthesis ◽  
Alternative Pathway ◽  
Mitochondrial Protein ◽  
Knock Out ◽  
Sphingomyelin Synthase ◽  
Mitochondrial Functions ◽  
Golgi Structure ◽  
Steroidogenic Cells ◽  
The Impact

The Acyl-CoA-binding domain-containing protein (ACBD3) plays multiple roles across the cell. Although generally associated with the Golgi apparatus, it operates also in mitochondria. In steroidogenic cells, ACBD3 is an important part of a multiprotein complex transporting cholesterol into mitochondria. Balance in mitochondrial cholesterol is essential for proper mitochondrial protein biosynthesis, among others. We generated ACBD3 knock-out (ACBD3-KO) HEK293 and HeLa cells and characterized the impact of protein absence on mitochondria, Golgi, and lipid profile. In ACBD3-KO cells, cholesterol level and mitochondrial structure and functions are not altered, demonstrating that an alternative pathway of cholesterol transport into mitochondria exists. However, ACBD3-KO cells exhibit enlarged Golgi area with absence of stacks and ribbon-like formation, confirming the importance of ACBD3 in Golgi stacking. The glycosylation of the LAMP2 glycoprotein was not affected by the altered Golgi structure. Moreover, decreased sphingomyelins together with normal ceramides and sphingomyelin synthase activity reveal the importance of ACBD3 in ceramide transport from ER to Golgi.

scholarly journals A Conserved Mitochondrial Chaperone-Protease Complex Involved in Protein Homeostasis

2021 ◽  
Vol 8 ◽  
Author(s):  
Mauro Serricchio ◽  
Peter Bütikofer
Keyword(s):  
Quality Control ◽  
Protein Complex ◽  
Elevated Temperatures ◽  
Protein Complexes ◽  
Mitochondrial Dynamics ◽  
Mitochondrial Protein ◽  
Culture Conditions ◽  
Inner Mitochondrial Membrane ◽  
Knock Out ◽  
Mitochondrial Functions

Mitochondria are essential organelles involved in cellular energy production. The inner mitochondrial membrane protein stomatin-like protein 2 (SLP-2) is a member of the SPFH (stomatin, prohibitin, flotilin, and HflK/C) superfamily and binds to the mitochondrial glycerophospholipid cardiolipin, forming cardiolipin-enriched membrane domains to promote the assembly and/or stabilization of protein complexes involved in oxidative phosphorylation. In addition, human SLP-2 anchors a mitochondrial processing complex required for proteolytic regulation of proteins involved in mitochondrial dynamics and quality control. We now show that deletion of the gene encoding the Trypanosoma brucei homolog TbSlp2 has no effect on respiratory protein complex stability and mitochondrial functions under normal culture conditions and is dispensable for growth of T. brucei parasites. In addition, we demonstrate that TbSlp2 binds to the metalloprotease TbYme1 and together they form a large mitochondrial protein complex. The two proteins negatively regulate each other’s expression levels by accelerating protein turnover. Furthermore, we show that TbYme1 plays a role in heat-stress resistance, as TbYme1 knock-out parasites displayed mitochondrial fragmentation and loss of viability when cultured at elevated temperatures. Unbiased interaction studies uncovered putative TbYme1 substrates, some of which were differentially affected by the absence of TbYme1. Our results support emerging evidence for the presence of mitochondrial quality control pathways in this ancient eukaryote.

scholarly journals Inhibition of p38 Mitogen-Activated Protein Kinase Impairs Mayaro Virus Replication in Human Dermal Fibroblasts and HeLa Cells

Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1156
Author(s):  
Madelaine Sugasti-Salazar ◽  
Yessica Y. Llamas-González ◽  
Dalkiria Campos ◽  
José González-Santamaría
Keyword(s):  
Protein Expression ◽  
Hela Cells ◽  
Plaque Assay ◽  
Dermal Fibroblasts ◽  
Dependent Manner ◽  
Human Dermal Fibroblasts ◽  
Mitogen Activated Protein ◽  
Mayaro Virus ◽  
The Impact ◽  
Dose Dependent

Mayaro virus (MAYV) hijacks the host’s cell machinery to effectively replicate. The mitogen-activated protein kinases (MAPKs) p38, JNK, and ERK1/2 have emerged as crucial cellular factors implicated in different stages of the viral cycle. However, whether MAYV uses these MAPKs to competently replicate has not yet been determined. The aim of this study was to evaluate the impact of MAPK inhibition on MAYV replication using primary human dermal fibroblasts (HDFs) and HeLa cells. Viral yields in supernatants from MAYV-infected cells treated or untreated with inhibitors SB203580, SP600125, U0126, or Losmapimod were quantified using plaque assay. Additionally, viral protein expression was analyzed using immunoblot and immunofluorescence. Knockdown of p38⍺/p38β isoforms was performed in HDFs using the PROTACs molecule NR-7h. Our data demonstrated that HDFs are highly susceptible to MAYV infection. SB203580, a p38 inhibitor, reduced MAYV replication in a dose-dependent manner in both HDFs and HeLa cells. Additionally, SB203580 significantly decreased viral E1 protein expression. Similarly, knockdown or inhibition of p38⍺/p38β isoforms with NR-7h or Losmapimod, respectively, affected MAYV replication in a dose-dependent manner. Collectively, these findings suggest that p38 could play an important role in MAYV replication and could serve as a therapeutic target to control MAYV infection.

scholarly journals Age-Dependent Decline in Neuron Growth Potential and Mitochondria Functions in Cortical Neurons

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1625
Author(s):  
Theresa C. Sutherland ◽  
Arthur Sefiani ◽  
Darijana Horvat ◽  
Taylor E. Huntington ◽  
Yuanjiu Lei ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Traumatic Injury ◽  
Axon Growth ◽  
Neurite Growth ◽  
Growth Potential ◽  
Mitochondrial Functions ◽  
Cord Injury ◽  
Age Dependent ◽  
Mitochondria Functions ◽  
The Impact

The age of incidence of spinal cord injury (SCI) and the average age of people living with SCI is continuously increasing. However, SCI is extensively modeled in young adult animals, hampering translation of research to clinical applications. While there has been significant progress in manipulating axon growth after injury, the impact of aging is still unknown. Mitochondria are essential to successful neurite and axon growth, while aging is associated with a decline in mitochondrial functions. Using isolation and culture of adult cortical neurons, we analyzed mitochondrial changes in 2-, 6-, 12- and 18-month-old mice. We observed reduced neurite growth in older neurons. Older neurons also showed dysfunctional respiration, reduced membrane potential, and altered mitochondrial membrane transport proteins; however, mitochondrial DNA (mtDNA) abundance and cellular ATP were increased. Taken together, these data suggest that dysfunctional mitochondria in older neurons may be associated with the age-dependent reduction in neurite growth. Both normal aging and traumatic injury are associated with mitochondrial dysfunction, posing a challenge for an aging SCI population as the two elements can combine to worsen injury outcomes. The results of this study highlight this as an area of great interest in CNS trauma.

scholarly journals OseIF3h Regulates Plant Growth and Pollen Development at Translational Level Presumably through Interaction with OsMTA2

Plants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1101
Author(s):  
Yuqing Huang ◽  
Peng Zheng ◽  
Xuejiao Liu ◽  
Hao Chen ◽  
Jumin Tu
Keyword(s):  
Plant Growth ◽  
Translation Initiation ◽  
Pollen Development ◽  
Messenger Rna ◽  
Protein Biosynthesis ◽  
Translation Initiation Factor ◽  
Initiation Factor ◽  
Sequencing Data ◽  
Knock Out ◽  
Translational Level

The initiation stage of protein biosynthesis is a sophisticated process tightly regulated by numerous initiation factors and their associated components. However, the mechanism underlying translation initiation has not been completely understood in rice. Here, we showed knock-out mutation of the rice eukaryotic translation initiation factor 3 subunit h (OseIF3h) resulted in plant growth retardation and seed-setting rate reduction as compared to the wild type. Further investigation demonstrated an interaction between OseIF3h and OsMTA2 (mRNA adenosine methylase 2), a rice homolog of METTL3 (methyltransferase-like 3) in mammals, which provided new insight into how N6-methyladenosine (m6A) modification of messenger RNA (mRNA) is engaged in the translation initiation process in monocot species. Moreover, the RIP-seq (RNA immunoprecipitation sequencing) data suggested that OseIF3h was involved in multiple biological processes, including photosynthesis, cellular metabolic process, precursor metabolites, and energy generation. Therefore, we infer that OseIF3h interacts with OsMTA2 to target a particular subset of genes at translational level, regulating plant growth and pollen development.

scholarly journals Exploring the Ability of LARS2 Carboxy-Terminal Domain in Rescuing the MELAS Phenotype

Life ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 674
Author(s):  
Francesco Capriglia ◽  
Francesca Rizzo ◽  
Giuseppe Petrosillo ◽  
Veronica Morea ◽  
Giulia d’Amati ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Molecular Mechanisms ◽  
Mitochondrial Protein ◽  
Trna Synthetase ◽  
Mitochondrial Protein Synthesis ◽  
Mitochondrial Translation ◽  
Terminal Domain ◽  
Carboxy Terminal Domain ◽  
Mitochondrial Functions ◽  
Carboxy Terminal

The m.3243A>G mutation within the mitochondrial mt-tRNALeu(UUR) gene is the most prevalent variant linked to mitochondrial encephalopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome. This pathogenic mutation causes severe impairment of mitochondrial protein synthesis due to alterations of the mutated tRNA, such as reduced aminoacylation and a lack of post-transcriptional modification. In transmitochondrial cybrids, overexpression of human mitochondrial leucyl-tRNA synthetase (LARS2) has proven effective in rescuing the phenotype associated with m.3243A>G substitution. The rescuing activity resides in the carboxy-terminal domain (Cterm) of the enzyme; however, the precise molecular mechanisms underlying this process have not been fully elucidated. To deepen our knowledge on the rescuing mechanisms, we demonstrated the interactions of the Cterm with mutated mt-tRNALeu(UUR) and its precursor in MELAS cybrids. Further, the effect of Cterm expression on mitochondrial functions was evaluated. We found that Cterm ameliorates de novo mitochondrial protein synthesis, whilst it has no effect on mt-tRNALeu(UUR) steady-state levels and aminoacylation. Despite the complete recovery of cell viability and the increase in mitochondrial translation, Cterm-overexpressing cybrids were not able to recover bioenergetic competence. These data suggest that, in our MELAS cell model, the beneficial effect of Cterm may be mediated by factors that are independent of the mitochondrial bioenergetics.

scholarly journals Developmental up-regulation of NMDA receptors in the prefrontal cortex and hippocampus of mGlu5 receptor knock-out mice

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Tiziana Imbriglio ◽  
Remy Verhaeghe ◽  
Nico Antenucci ◽  
Stefania Maccari ◽  
Giuseppe Battaglia ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Nmda Receptor ◽  
Metabotropic Glutamate Receptors ◽  
Adult Life ◽  
Developmental Time ◽  
Postnatal Life ◽  
Developmental Studies ◽  
Knock Out ◽  
Nmda Receptor Subunits ◽  
The Impact

AbstractmGlu5 metabotropic glutamate receptors are highly expressed and functional in the early postnatal life, and are known to positively modulate NMDA receptor function. Here, we examined the expression of NMDA receptor subunits and interneuron-related genes in the prefrontal cortex and hippocampus of mGlu5−/− mice and wild-type littermates at three developmental time points (PND9, − 21, and − 75). We were surprised to find that expression of all NMDA receptor subunits was greatly enhanced in mGlu5−/− mice at PND21. In contrast, at PND9, expression of the GluN2B subunit was enhanced, whereas expression of GluN2A and GluN2D subunits was reduced in both regions. These modifications were transient and disappeared in the adult life (PND75). Changes in the transcripts of interneuron-related genes (encoding parvalbumin, somatostatin, vasoactive intestinal peptide, reelin, and the two isoforms of glutamate decarboxylase) were also observed in mGlu5−/− mice across postnatal development. For example, the transcript encoding parvalbumin was up-regulated in the prefrontal cortex of mGlu5−/− mice at PND9 and PND21, whereas it was significantly reduced at PND75. These findings suggest that in mGlu5−/− mice a transient overexpression of NMDA receptor subunits may compensate for the lack of the NMDA receptor partner, mGlu5. Interestingly, in mGlu5−/− mice the behavioral response to the NMDA channel blocker, MK-801, was significantly increased at PND21, and largely reduced at PND75. The impact of adaptive changes in the expression of NMDA receptor subunits should be taken into account when mGlu5−/− mice are used for developmental studies.

Androgen Control of Mitochondrial Protein Biosynthesis in Male Sex Accessory Tissue and Liver of Rats1

Endocrinology ◽  
1971 ◽  
Vol 89 (2) ◽  
pp. 338-346 ◽  
Author(s):  
K. A. DOEG ◽  
L. L. POLOMSKI ◽  
L. H. DOEG ◽  
P. M. DUBOS
Keyword(s):  
Protein Biosynthesis ◽  
Mitochondrial Protein ◽  
Male Sex

Unstable mitochondrial DNA in natural-death nuclear mutants of Neurospora crassa

1989 ◽  
Vol 9 (10) ◽  
pp. 4259-4264
Author(s):  
B L Seidel-Rogol ◽  
J King ◽  
H Bertrand
Keyword(s):  
Neurospora Crassa ◽  
Mitochondrial Protein ◽  
Nuclear Gene ◽  
Recessive Mutation ◽  
Natural Death ◽  
Mitochondrial Ribosomes ◽  
Large Deletions ◽  
Group I ◽  
Mitochondrial Functions ◽  
Mitochondrial Chromosome

The natural-death mutant of Neurospora crassa has an accelerated senescence phenotype caused by a recessive mutation, nd, in a nuclear gene that is located in linkage group I. An examination of mitochondrial functions, however, revealed that the mutant has phenotypic and molecular defects similar to those commonly associated with maternally transmitted fungal senescence syndromes, including (i) deficiencies in cytochromes aa3 and b; (ii) a deficit in small subunits of mitochondrial ribosomes, and hence defective mitochondrial protein synthesis; and (iii) accumulation of gross rearrangements, including large deletions, in the mitochondrial chromosome of vegetatively propagated cells. These traits indicate that the nd+ allele codes for a function that is essential for stable maintenance of the mitochondrial chromosome, possibly a protein involved in replication, repair, or recombination.

scholarly journals Unstable mitochondrial DNA in natural-death nuclear mutants of Neurospora crassa.

1989 ◽  
Vol 9 (10) ◽  
pp. 4259-4264 ◽  
Author(s):  
B L Seidel-Rogol ◽  
J King ◽  
H Bertrand
Keyword(s):  
Neurospora Crassa ◽  
Mitochondrial Protein ◽  
Nuclear Gene ◽  
Recessive Mutation ◽  
Natural Death ◽  
Mitochondrial Ribosomes ◽  
Large Deletions ◽  
Group I ◽  
Mitochondrial Functions ◽  
Mitochondrial Chromosome

The natural-death mutant of Neurospora crassa has an accelerated senescence phenotype caused by a recessive mutation, nd, in a nuclear gene that is located in linkage group I. An examination of mitochondrial functions, however, revealed that the mutant has phenotypic and molecular defects similar to those commonly associated with maternally transmitted fungal senescence syndromes, including (i) deficiencies in cytochromes aa3 and b; (ii) a deficit in small subunits of mitochondrial ribosomes, and hence defective mitochondrial protein synthesis; and (iii) accumulation of gross rearrangements, including large deletions, in the mitochondrial chromosome of vegetatively propagated cells. These traits indicate that the nd+ allele codes for a function that is essential for stable maintenance of the mitochondrial chromosome, possibly a protein involved in replication, repair, or recombination.

scholarly journals Metabolomic and transcriptomic analysis reveals endogenous substrates and metabolic adaptation in rats lacking Abcg2 and Abcb1a transporters

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253852
Author(s):  
Samit Ganguly ◽  
David Finkelstein ◽  
Timothy I. Shaw ◽  
Ryan D. Michalek ◽  
Kimberly M. Zorn ◽  
...  
Keyword(s):  
Uric Acid ◽  
Rat Plasma ◽  
Drug Clearance ◽  
Transcriptomic Analysis ◽  
Metabolic Adaptation ◽  
Sprague Dawley ◽  
Knock Out ◽  
Primary Driver ◽  
Endogenous Substrates ◽  
The Impact

Abcg2/Bcrp and Abcb1a/Pgp are xenobiotic efflux transporters limiting substrate permeability in the gastrointestinal system and brain, and increasing renal and hepatic drug clearance. The systemic impact of Bcrp and Pgp ablation on metabolic homeostasis of endogenous substrates is incompletely understood. We performed untargeted metabolomics of cerebrospinal fluid (CSF) and plasma, transcriptomics of brain, liver and kidney from male Sprague Dawley rats (WT) and Bcrp/Pgp double knock-out (dKO) rats, and integrated metabolomic/transcriptomic analysis to identify putative substrates and perturbations in canonical metabolic pathways. A predictive Bayesian machine learning model was used to predict in silico those metabolites with greater substrate-like features for either transporters. The CSF and plasma levels of 169 metabolites, nutrients, signaling molecules, antioxidants and lipids were significantly altered in dKO rats, compared to WT rats. These metabolite changes suggested alterations in histidine, branched chain amino acid, purine and pyrimidine metabolism in the dKO rats. Levels of methylated and sulfated metabolites and some primary bile acids were increased in dKO CSF or plasma. Elevated uric acid levels appeared to be a primary driver of changes in purine and pyrimidine biosynthesis. Alterations in Bcrp/Pgp dKO CSF levels of antioxidants, precursors of neurotransmitters, and uric acid suggests the transporters may contribute to the regulation of a healthy central nervous system in rats. Microbiome-generated metabolites were found to be elevated in dKO rat plasma and CSF. The altered dKO metabolome appeared to cause compensatory transcriptional change in urate biosynthesis and response to lipopolysaccharide in brain, oxidation-reduction processes and response to oxidative stress and porphyrin biosynthesis in kidney, and circadian rhythm genes in liver. These findings present insight into endogenous functions of Bcrp and Pgp, the impact that transporter substrates, inhibitors or polymorphisms may have on metabolism, how transporter inhibition could rewire drug sensitivity indirectly through metabolic changes, and identify functional Bcrp biomarkers.

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