scholarly journals MTSviewer: a database to visualize mitochondrial targeting sequences, cleavage sites, and mutations on protein structures

2021 ◽  
Author(s):  
Andrew N Bayne ◽  
Jing Dong ◽  
Saeid Amiri ◽  
Sali M.K. Farhan ◽  
Jean-Francois Trempe
Keyword(s):  
Functional Characterization ◽  
Protein Structures ◽  
Cleavage Sites ◽  
Mitochondrial Targeting ◽  
Regulatory Pathways ◽  
Mitochondrial Proteome ◽  
Mitochondrial Processing Peptidase ◽  
R Shiny ◽  
Cardiovascular Defects ◽  
Mitochondrial Targeting Sequences

Mitochondrial dysfunction is implicated in a wide array of human diseases ranging from neurodegenerative disorders to cardiovascular defects. The coordinated localization and import of proteins into mitochondria is an essential process that ensures mitochondrial homeostasis and consequently cell survival. The localization and import of most mitochondrial proteins are driven by N-terminal mitochondrial targeting sequences (MTS), which interact with import machinery and are removed by the mitochondrial processing peptidase (MPP). The recent discovery of internal MTS's - those which are distributed throughout a protein and act as import regulators or secondary MPP cleavage sites - has expanded the role of both MTS's and MPP beyond conventional N-terminal regulatory pathways. Still, the global mutational landscape of MTS's remains poorly characterized, both from genetic and structural perspectives. To this end, we have integrated a variety of prediction tools into one harmonized R/Shiny database called MTSviewer, which combines MTS predictions, MPP cleavage sites, genetic variants, pathogenicity predictions, and N-terminomics data with structural visualization using AlphaFold models. Using this platform, we have generated a list of disease-linked variants in protein MTS's and their predicted consequences as a resource for their functional characterization. Overall, MTSviewer is a platform that can be used to interrogate MTS mutations and their potential effects on import and proteolysis across the mitochondrial proteome.

scholarly journals MitoFates: Improved Prediction of Mitochondrial Targeting Sequences and Their Cleavage Sites

2015 ◽  
Vol 14 (4) ◽  
pp. 1113-1126 ◽  
Author(s):  
Yoshinori Fukasawa ◽  
Junko Tsuji ◽  
Szu-Chin Fu ◽  
Kentaro Tomii ◽  
Paul Horton ◽  
...  
Keyword(s):  
Cleavage Sites ◽  
Mitochondrial Targeting ◽  
Mitochondrial Targeting Sequences

Insights into the biochemical and functional characterization of sortase E transpeptidase of Corynebacterium glutamicum

2019 ◽  
Vol 476 (24) ◽  
pp. 3835-3847 ◽  
Author(s):  
Aliyath Susmitha ◽  
Kesavan Madhavan Nampoothiri ◽  
Harsha Bajaj
Keyword(s):  
Protein Engineering ◽  
Cell Attachment ◽  
Functional Characterization ◽  
Protein Structures ◽  
Structural Similarity ◽  
Surface Proteins ◽  
Sortase A ◽  
Peptide Cleavage ◽  
New Findings

Most Gram-positive bacteria contain a membrane-bound transpeptidase known as sortase which covalently incorporates the surface proteins on to the cell wall. The sortase-displayed protein structures are involved in cell attachment, nutrient uptake and aerial hyphae formation. Among the six classes of sortase (A–F), sortase A of S. aureus is the well-characterized housekeeping enzyme considered as an ideal drug target and a valuable biochemical reagent for protein engineering. Similar to SrtA, class E sortase in GC rich bacteria plays a housekeeping role which is not studied extensively. However, C. glutamicum ATCC 13032, an industrially important organism known for amino acid production, carries a single putative sortase (NCgl2838) gene but neither in vitro peptide cleavage activity nor biochemical characterizations have been investigated. Here, we identified that the gene is having a sortase activity and analyzed its structural similarity with Cd-SrtF. The purified enzyme showed a greater affinity toward LAXTG substrate with a calculated KM of 12 ± 1 µM, one of the highest affinities reported for this class of enzyme. Moreover, site-directed mutation studies were carried to ascertain the structure functional relationship of Cg-SrtE and all these are new findings which will enable us to perceive exciting protein engineering applications with this class of enzyme from a non-pathogenic microbe.

scholarly journals Characterization of novel regulators for heat stress tolerance in tomato from Indian sub-continent

2019 ◽  
Author(s):  
Sonia Balyan ◽  
Sombir Rao ◽  
Sarita Jha ◽  
Chandni Bansal ◽  
Jaishri Rubina Das ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Heat Stress ◽  
Functional Characterization ◽  
Transcriptome Profiling ◽  
Negative Regulator ◽  
Comparative Transcriptome ◽  
Regulatory Pathways ◽  
Cool Region ◽  
Promoter Swapping

AbstractThe footprint of tomato cultivation, a cool region crop that exhibits heat stress (HS) sensitivity, is increasing in the tropics/sub-tropics. Knowledge of novel regulatory hot-spots from varieties growing in the Indian sub-continent climatic zones could be vital for developing HS-resilient crops. Comparative transcriptome-wide signatures of a tolerant (CLN1621L) and sensitive (CA4) cultivar-pair short-listed from a pool of varieties exhibiting variable thermo-sensitivity using physiological, survival and yield-related traits revealed redundant to cultivar-specific HS-regulation with more up-regulated genes for CLN1621L than CA4. The anatgonisiticly-expressing genes include enzymes; have roles in plant defense and response to different abiotic stresses. Functional characterization of three antagonistic genes by overexpression and TRV-VIGS silencing established Solyc09g014280 (Acylsugar acyltransferase) and Solyc07g056570 (Notabilis), that are up-regulated in tolerant cultivar, as positive regulators of HS-tolerance and Solyc03g020030 (Pin-II proteinase inhibitor), that is down-regulated in CLN1621L, as negative regulator of thermotolerance. Transcriptional assessment of promoters of these genes by SNPs in stress-responsive cis-elements and promoter swapping experiments in opposite cultivar background showed inherent cultivar-specific orchestration of transcription factors in regulating transcription. Moreover, overexpression of three ethylene response transcription factors (ERF.C1/F4/F5) also improved HS-tolerance in tomato. This study identifies several novel HS-tolerance genes and provides proof of their utility in tomato-thermotolerance.HighlightNovel heat stress regulatory pathways uncovered by comparative transcriptome profiling between contrasting tomato cultivars from Indian sub-continent for improving thermotolerance. (20/30)

scholarly journals Functional Characterization of the obesity-linked variant of the β3-adrenergic receptor

2021 ◽  
Author(s):  
Esraa Haji ◽  
Saeed Al Mahri ◽  
Yumna Aloraij ◽  
Shuja Shafi Malik ◽  
Sameer Mohammad
Keyword(s):  
Cell Surface ◽  
Adrenergic Receptor ◽  
Functional Characterization ◽  
Biochemical Properties ◽  
Cell Surface Expression ◽  
Cellular Distribution ◽  
Hek 293 ◽  
Regulatory Pathways ◽  
Beta 2 ◽  
Activation Behavior

Adrenergic receptor β3 (ADRβ3) is a member of the rhodopsin-like G protein-coupled receptor family. The binding of the ligand to ADRβ3 activates adenylate cyclase and increases cAMP in the cells. ADRβ3 is highly expressed in white and brown adipocytes and controls key regulatory pathways of lipid metabolism. Trp64Arg (W64R) polymorphism in the ADRβ3 has been associated with the early development of type 2 diabetes mellitus, lower resting metabolic rate, abdominal obesity, and insulin resistance. It is unclear how the substitution of W64R affects the functioning of ADRβ3. This study was initiated to functionally characterize this obesity-linked variant of ADRβ3. We evaluated in detail the expression, subcellular distribution, and post-activation behavior of the WT and W64R ADRβ3 using a single cell quantitative fluorescence microscopy. When expressed in HEK 293 cells, ADRβ3 shows a typical distribution displayed by other GPCRs with a predominant localization at the cell surface. Unlike Adrenergic receptor β2 (ADRβ2), agonist induced desensitization of ADRβ3 does not involve loss of cell surface expression. WT and W64R variant of ADRβ3 displayed comparable biochemical properties and there was no significant impact of the substitution of Tryptophan with Arginine on the expression, cellular distribution, signaling, and post-activation behavior of ADRβ3. The obesity-linked W64R variant of ADRβ3 is indistinguishable from the WT ADRβ3 in terms of expression, cellular distribution, signaling, and post-activation behavior.

Attenuation of the hypoxia-induced protein kinase Cδ interaction with the ‘d’ subunit of F1Fo-ATP synthase in neonatal cardiac myocytes: implications for energy preservation and survival

2010 ◽  
Vol 429 (2) ◽  
pp. 335-345 ◽  
Author(s):  
Tiffany T. Nguyen ◽  
Mourad Ogbi ◽  
Qilin Yu ◽  
John A. Johnson
Keyword(s):  
Protein Kinase ◽  
Atpase Activity ◽  
Atp Synthase ◽  
Mitochondrial Targeting ◽  
F1fo Atp Synthase ◽  
Hiv Tat ◽  
F1fo Atpase ◽  
D Subunit ◽  
Mitochondrial Targeting Sequences ◽  
Protein Kinase Cδ

The F1Fo-ATP synthase provides most of the heart's energy, yet events that alter its function during injury are poorly understood. Recently, we described a potent inhibitory effect on F1Fo-ATP synthase function mediated by the interaction of PKCδ (protein kinase Cδ) with dF1Fo (‘d’ subunit of the F1Fo-ATPase/ATP synthase). We have now developed novel peptide modulators which facilitate or inhibit the PKCδ–dF1Fo interaction. These peptides include HIV-Tat (transactivator of transcription) protein transduction and mammalian mitochondrial-targeting sequences. Pre-incubation of NCMs (neonatal cardiac myocyte) with 10 nM extracellular concentrations of the mitochondrial-targeted PKCδ–dF1Fo interaction inhibitor decreased Hx (hypoxia)-induced co-IP (co-immunoprecipitation) of PKCδ with dF1Fo by 40±9%, abolished Hx-induced inhibition of F1Fo-ATPase activity, attenuated Hx-induced losses in F1Fo-derived ATP and protected against Hx- and reperfusion-induced cell death. A scrambled-sequence (inactive) peptide, which contained HIV-Tat and mitochondrial-targeting sequences, was without effect. In contrast, the cell-permeant mitochondrial-targeted PKCδ–dF1Fo facilitator peptide, which we have shown previously to induce the PKCδ–dF1Fo co-IP, was found to inhibit F1Fo-ATPase activity to an extent similar to that caused by Hx alone. The PKCδ–dF1Fo facilitator peptide also decreased ATP levels by 72±18% under hypoxic conditions in the presence of glycolytic inhibition. None of the PKCδ–dF1Fo modulatory peptides altered the inner mitochondrial membrane potential. Our studies provide the first evidence that disruption of the PKCδ–dF1Fo interaction using cell-permeant mitochondrial-targeted peptides attenuates cardiac injury resulting from prolonged oxygen deprivation.

scholarly journals Functional characterization of 3D protein structures informed by human genetic diversity

2019 ◽  
Vol 116 (18) ◽  
pp. 8960-8965 ◽  
Author(s):  
Michael Hicks ◽  
Istvan Bartha ◽  
Julia di Iulio ◽  
J. Craig Venter ◽  
Amalio Telenti
Keyword(s):  
Large Scale ◽  
Functional Characterization ◽  
Protein Structures ◽  
Large Scale Data ◽  
Allosteric Sites ◽  
Missense Variation ◽  
Binding Pockets ◽  
Definition Of ◽  
Scale Data

Sequence variation data of the human proteome can be used to analyze 3D protein structures to derive functional insights. We used genetic variant data from nearly 140,000 individuals to analyze 3D positional conservation in 4,715 proteins and 3,951 homology models using 860,292 missense and 465,886 synonymous variants. Sixty percent of protein structures harbor at least one intolerant 3D site as defined by significant depletion of observed over expected missense variation. Structural intolerance data correlated with deep mutational scanning functional readouts for PPARG, MAPK1/ERK2, UBE2I, SUMO1, PTEN, CALM1, CALM2, and TPK1 and with shallow mutagenesis data for 1,026 proteins. The 3D structural intolerance analysis revealed different features for ligand binding pockets and orthosteric and allosteric sites. Large-scale data on human genetic variation support a definition of functional 3D sites proteome-wide.

Getting into mitochondria

2016 ◽  
Vol 473 (21) ◽  
pp. 3755-3758 ◽  
Author(s):  
Ján A. Miernyk
Keyword(s):  
Secondary Structure ◽  
Glutamate Dehydrogenase ◽  
Protein Import ◽  
Terminal Region ◽  
Nuclear Genes ◽  
Cleavage Sites ◽  
Mitochondrial Targeting ◽  
Limited Ability ◽  
Secondary Structure Predictions ◽  
High Matrix

The human mitochondrial glutamate dehydrogenase isoenzymes (hGDH1 and hGDH2) are abundant matrix-localized proteins encoded by nuclear genes. The proteins are synthesized in the cytoplasm, with an atypically long N-terminal mitochondrial targeting sequence (MTS). The results of secondary structure predictions suggest the presence of two α-helices within the N-terminal region of the MTS. Results from deletion analyses indicate that individual helices have limited ability to direct protein import and matrix localization, but that there is a synergistic interaction when both helices are present [Biochem. J. (2016) 473, 2813–2829]. Mutagenesis of the MTS cleavage sites blocked post-import removal of the presequences, but did not impede import. The authors propose that the high matrix levels of hGDH can be attributed to the unusual length and secondary structure of the MTS.

scholarly journals Sequence Analysis and Structure Prediction of Malaysia SARS-CoV-2 Strain’s Structural and Accessory Proteins

2021 ◽  
Vol 12 (3) ◽  
pp. 3259-3304
Keyword(s):  
Structure Prediction ◽  
Active Sites ◽  
Homo Sapiens ◽  
Functional Characterization ◽  
Protein Structures ◽  
Three Dimensional ◽  
Experimental Models ◽  
Amino Acid Sequences ◽  
Accessory Proteins ◽  
Evolutionary Analysis

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that transmitted from animal to human became a life-threatening pandemic in 2020. Scientists are currently testing several drugs to eradicate the COVID-19 outbreak. However, there is no 100 % effective drug or vaccine against SARS-CoV-2 has been discovered so far. In this study, we explored the structure prediction and functional analysis of 75 Malaysia SARS-CoV-2 strain’s structural and accessory proteins without the presence of experimental models. Physiochemical analysis, secondary structure analysis, structure prediction, functional characterization, active site identification, and evolutionary analysis based on the amino acid sequences retrieved from National Centre for Biotechnology Information (NCBI). Three-dimensional (3-D) protein structures were built using the Swiss model. The quality of protein models was verified by ERRAT, PROCHECK, and Verify 3D tools. Active prediction analysis revealed the high potential active sites of proteins where the anti-viral drug or vaccine may bind and inhibit the viral activities. Molecular phylogenetic analysis of ORF10, ORF8, and ORF6 proteins from five different species was analyzed. The results from this analysis proved that Homo sapiens SARS-CoV-2 had high genetic similarity with the bat coronavirus. These analyses may help in designing structure-based anti-viral drugs or to develop potential vaccines for SARS-CoV-2.

scholarly journals Sequential digestion with Trypsin and Elastase in cross-linking/mass spectrometry

2018 ◽  
Author(s):  
Therese Dau ◽  
Kapil Gupta ◽  
Imre Berger ◽  
Juri Rappsilber
Keyword(s):  
Mass Spectrometry ◽  
Protein Interactions ◽  
Protein Structures ◽  
Cross Linking ◽  
Cleavage Sites ◽  
Protein Modelling ◽  
Protein Protein Interactions ◽  
Important Approach ◽  
Cross Links ◽  
Sequential Digestion

ABSTRACTCross-linking/mass spectrometry has become an important approach for studying protein structures and protein-protein interactions. The amino acid composition of some protein regions impedes the detection of cross-linked residues, although it would yield invaluable information for protein modelling. Here, we report on a sequential digestion strategy with trypsin and elastase to penetrate regions with a low density of trypsin cleavage sites. We exploited intrinsic substrate recognition properties of elastase to specifically target larger tryptic peptides. Our application of this protocol to the TAF4-12 complex allowed us to identify cross-links in previously inaccessible regions.

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