scholarly journals Members of the GADD45 Protein Family Show Distinct Propensities to form Toxic Amyloid-Like Aggregates in Physiological Conditions

2021 ◽  
Vol 22 (19) ◽  
pp. 10700
Author(s):  
Giovanni Smaldone ◽  
Daniela Caruso ◽  
Annamaria Sandomenico ◽  
Emanuela Iaccarino ◽  
Annalia Focà ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Protein Family ◽  
Label Free ◽  
Cellular Functions ◽  
Physiological Conditions ◽  
Toxic Species ◽  
High Molecular Weight Species ◽  
Functional Implications ◽  
Uv Visible ◽  
Strong Interactors

The three members (GADD45α, GADD45β, and GADD45γ) of the growth arrest and DNA damage-inducible 45 (GADD45) protein family are involved in a myriad of diversified cellular functions. With the aim of unravelling analogies and differences, we performed comparative biochemical and biophysical analyses on the three proteins. The characterization and quantification of their binding to the MKK7 kinase, a validated functional partner of GADD45β, indicate that GADD45α and GADD45γ are strong interactors of the kinase. Despite their remarkable sequence similarity, the three proteins present rather distinct biophysical properties. Indeed, while GADD45β and GADD45γ are marginally stable at physiological temperatures, GADD45α presents the Tm value expected for a protein isolated from a mesophilic organism. Surprisingly, GADD45α and GADD45β, when heated, form high-molecular weight species that exhibit features (ThT binding and intrinsic label-free UV/visible fluorescence) proper of amyloid-like aggregates. Cell viability studies demonstrate that they are endowed with a remarkable toxicity against SHSY-5Y and HepG2 cells. The very uncommon property of GADD45β to form cytotoxic species in near-physiological conditions represents a puzzling finding with potential functional implications. Finally, the low stability and/or the propensity to form toxic species of GADD45 proteins constitute important features that should be considered in interpreting their many functions.

scholarly journals Serum proteomics identify potential biomarkers for nasopharyngeal carcinoma sensitivity to radiotherapy

2019 ◽  
Vol 39 (5) ◽  
Author(s):  
Guangying Zhang ◽  
Kun Zhang ◽  
Chao Li ◽  
Yanyan Li ◽  
Zhanzhan Li ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Serum Proteins ◽  
Sequence Similarity ◽  
Predictive Biomarkers ◽  
Primary Treatment ◽  
Label Free ◽  
Discrimination Ability ◽  
Serum Proteomics ◽  
High Discrimination ◽  
Southern University

Abstract Radiotherapy is the primary treatment option for nasopharyngeal carcinoma (NPC). Local recurrence and metastasis caused by radioresistance become a bottleneck of curative effect for patients with NPC. Currently, serum predictive biomarkers of radioresistance are scare. We enrolled NPC patients, who underwent radiotherapy in the Department of Oncology, Xiangya Hospital, Central Southern University, and analyzed the serum proteins profiles in NPC patients using with quantitative label-free proteomics using ultra-definition MS. Patients were divided into those who were radioresistant and radiosensitive by the overall reduction (≤50% or >50%, respectively) in tumor extent. The MS/MS spectrum database search identified 911 proteins and 809 proteins are quantitatable. Eight proteins significantly up-regulated and 12 serum proteins were significantly down-regulated in the radioresistance group compared with radiosensitivity group (P<0.05). Finally, five proteins entered the optimal models, including secreted protein acidic and cysteine rich (SPARC) (P=0.032), serpin family D member 1S (ERPIND1) (P=0.040), complement C4B (C4B) (P=0.017), peptidylprolyl Isomerase B (PPIB) (P=0.042), and family with sequence similarity 173 member A (FAM173A) (P=0.017). In all patient, the area under the curves (AUC) for SPARC, SERPIND, C4B, PPIB, and FAM173A were 0.716 (95% CI: 0.574–0.881), 0.697 (95% CI: 0.837–0.858), 0.686 (95% CI: 0.522–0.850), 0.668 (95% CI: 0.502–0.834) and 0.657 (95% CI: 0.512–0.825), respectively. The AUC of five selected proteins was 0.968 (95% CI: 0.918–1.000) with the sensitivity of 0.941 and the specificity of 0.926. Our result indicated that a panel including five serum protein (SPARC SERPIND1 C4B PPIB FAM173A) based on serum proteomics provided a high discrimination ability for radiotherapy effects in NPC patients. Studies with larger sample size and longer follow-up outcome are required.

scholarly journals The Arabidopsis Mitochondrial Glutaredoxin GRXS15 Provides [2Fe-2S] Clusters for ISCA-Mediated [4Fe-4S] Cluster Maturation

2020 ◽  
Vol 21 (23) ◽  
pp. 9237
Author(s):  
Tamanna Azam ◽  
Jonathan Przybyla-Toscano ◽  
Florence Vignols ◽  
Jérémy Couturier ◽  
Nicolas Rouhier ◽  
...  
Keyword(s):  
Resonance Raman Spectroscopy ◽  
Cd Spectroscopy ◽  
Bimolecular Fluorescence Complementation ◽  
Cluster Assembly ◽  
Cellular Functions ◽  
Visible Absorption ◽  
Uv Visible ◽  
S Proteins

Iron-sulfur (Fe-S) proteins are crucial for many cellular functions, particularly those involving electron transfer and metabolic reactions. An essential monothiol glutaredoxin GRXS15 plays a key role in the maturation of plant mitochondrial Fe-S proteins. However, its specific molecular function is not clear, and may be different from that of the better characterized yeast and human orthologs, based on known properties. Hence, we report here a detailed characterization of the interactions between Arabidopsis thaliana GRXS15 and ISCA proteins using both in vivo and in vitro approaches. Yeast two-hybrid and bimolecular fluorescence complementation experiments demonstrated that GRXS15 interacts with each of the three plant mitochondrial ISCA1a/1b/2 proteins. UV-visible absorption/CD and resonance Raman spectroscopy demonstrated that coexpression of ISCA1a and ISCA2 resulted in samples with one [2Fe-2S]2+ cluster per ISCA1a/2 heterodimer, but cluster reconstitution using as-purified [2Fe-2S]-ISCA1a/2 resulted in a [4Fe-4S]2+ cluster-bound ISCA1a/2 heterodimer. Cluster transfer reactions monitored by UV-visible absorption and CD spectroscopy demonstrated that [2Fe-2S]-GRXS15 mediates [2Fe-2S]2+ cluster assembly on mitochondrial ferredoxin and [4Fe-4S]2+ cluster assembly on the ISCA1a/2 heterodimer in the presence of excess glutathione. This suggests that ISCA1a/2 is an assembler of [4Fe-4S]2+ clusters, via two-electron reductive coupling of two [2Fe-2S]2+ clusters. Overall, the results provide new insights into the roles of GRXS15 and ISCA1a/2 in effecting [2Fe-2S]2+ to [4Fe-4S]2+ cluster conversions for the maturation of client [4Fe-4S] cluster-containing proteins in plants.

scholarly journals Does it take two to tango? RING domain self-association and activity in TRIM E3 ubiquitin ligases

2020 ◽  
Vol 48 (6) ◽  
pp. 2615-2624
Author(s):  
Filippo Fiorentini ◽  
Diego Esposito ◽  
Katrin Rittinger
Keyword(s):  
Coiled Coil ◽  
E3 Ligase ◽  
Protein Family ◽  
Ring Domain ◽  
Cellular Functions ◽  
Protein Activity ◽  
Coiled Coil Region ◽  
Tripartite Motif ◽  
Large Protein Family ◽  
Self Association

TRIM proteins form a protein family that is characterized by a conserved tripartite motif domain comprising a RING domain, one or two B-box domains and a coiled-coil region. Members of this large protein family are important regulators of numerous cellular functions including innate immune responses, transcriptional regulation and apoptosis. Key to their cellular role is their E3 ligase activity which is conferred by the RING domain. Self-association is an important characteristic of TRIM protein activity and is mediated by homodimerization via the coiled-coil region, and in some cases higher order association via additional domains of the tripartite motif. In many of the TRIM family proteins studied thus far, RING dimerization is an important prerequisite for E3 ligase enzymatic activity though the propensity of RING domains to dimerize differs significantly between different TRIMs and can be influenced by other regions of the protein.

scholarly journals Prediction of Sub-cellular Localization of Scramblase Protein Family

2010 ◽  
pp. 187-195
Author(s):  
Babita Sahoo ◽  
Santosh Kumar Sahu ◽  
Tripti Swarnkar
Keyword(s):  
Subcellular Localization ◽  
Cellular Localization ◽  
Protein Family ◽  
Cellular Functions

In the present work, we discuss an anaysis about the localization of different members of scramblase protein family. Different scramblase sequences were picked up from organisms of all eukaryotic phyla and their localization were predicted using the P-SORT programme. Our analysis showed that the scramblase protein family shows multiple subcellular localization. Most proteins were found to be localized to the cytoplasm, where as others were found to be present in the nucleus or mitochondria. Interestingly, we found that in yeast, all putative scramblases were localized in the nucleus with a reliability of more than 95%. Our analysis shows that scramblases are a family of protein having diversed cellular localization and hence hypothesized to be performing multiple cellular functions in various organisms.

scholarly journals Novel roles for mammalian septins: from vesicle trafficking to oncogenesis

2001 ◽  
Vol 114 (5) ◽  
pp. 839-844 ◽  
Author(s):  
B. Kartmann ◽  
D. Roth
Keyword(s):  
Plasma Membrane ◽  
Recent Work ◽  
Cell Biology ◽  
Vesicle Trafficking ◽  
Family Members ◽  
Protein Family ◽  
Cellular Functions ◽  
Cellular Processes ◽  
Sequence Homologies ◽  
Genome Analyses

In recent years a convergence of various aspects of cell biology has become apparent, and yet investigators are only beginning to grasp the underlying unifying mechanisms. Among the proteins that participate in diverse aspects of cell biology are the septins. These are a group of novel GTPase proteins that are broadly distributed in many eukaryotes except plants. Although septins were originally identified as a protein family involved in cytokinesis in yeast, recent advances in the field have now ascribed additional functions to these proteins. In particular, the number of known mammalian septin family members has increased dramatically as more data has become available through genome analyses. We suggest a classification for the mammalian septins based on the sequence homologies in their highly divergent N- and C-termini. Recent work suggests novel functions for septins in vesicle trafficking, oncogenesis and compartmentalization of the plasma membrane. Given the ability of the septins to bind GTP and phosphatidylinositol 4,5-bisphosphate in a mutually exclusive manner, these proteins might be crucial elements for the spatial and/or temporal control of diverse cellular functions. As the functions of the septins become unraveled, our understanding of seemingly different cellular processes may move a step further.

scholarly journals Biochemical characterization of androgen receptor-interacting protein 4

2006 ◽  
Vol 393 (3) ◽  
pp. 789-795 ◽  
Author(s):  
Andrii Domanskyi ◽  
Katja T. Virtanen ◽  
Jorma J. Palvimo ◽  
Olli A. Jänne
Keyword(s):  
Androgen Receptor ◽  
Biochemical Characterization ◽  
Specific Activity ◽  
Protein Complexes ◽  
Sequence Similarity ◽  
Protein Family ◽  
Interacting Protein ◽  
Attachment Sites

ARIP4 [AR (androgen receptor)-interacting protein 4] is a member of the SNF2-like family of proteins. Its sequence similarity to known proteins is restricted to the centrally located SNF2 ATPase domain. ARIP4 is an active ATPase, and dsDNA (double-stranded DNA) and ssDNA (single-stranded DNA) enhance its catalytic activity. We show in the present study that ARIP4 interacts with AR and binds to DNA and mononucleosomes. The N-terminal region of ARIP4 mediates interaction with AR. Kinetic parameters of the ARIP4 ATPase are similar to those of BRG-1 and SNF2h, two members of the SNF2-like protein family, but the specific activity of ARIP4 protein purified to >90% homogeneity is approximately ten times lower, being 120 molecules of ATP hydrolysed by an ARIP4 molecule per min in contrast with approx. 1000 ATP molecules hydrolysed per min by ATP-dependent chromatin remodellers. Unlike other members of the SNF2 family, ARIP4 does not appear to form large protein complexes in vivo or remodel mononucleosomes in vitro. ARIP4 is covalently modified by sumoylation, and mutation of six potential SUMO (small ubiquitin-related modifier) attachment sites abolished the ability of ARIP4 to bind DNA, hydrolyse ATP and activate AR function. We conclude that, similar to its closest homologues in the SNF2-like protein family, ATRX (α-thalassemia, mental retardation, X-linked) and Rad54, ARIP4 does not seem to be a classical chromatin remodelling protein.

In VitroDiagnostic Device with a Bio-Coupled Gate Field Effect Transistor

2018 ◽  
Vol 12 (1) ◽  
pp. 45-51 ◽  
Author(s):  
Toshiya Sakata ◽  
Keyword(s):  
Semiconductor Device ◽  
Direct Detection ◽  
Cell Communication ◽  
Label Free ◽  
Cellular Functions ◽  
Biological Phenomena ◽  
Communication Processes ◽  
Antigen Antibody ◽  
Antibody Interactions

In this study, we report a simple and rapid biosensing method for the analysis andin vitromonitoring of biological processes, including DNAbinding events, antigen-antibody interactions, and cellular functions, using a semiconductor device. Most biological phenomena involve cell-cell communication processes that are mediated by the transport of sodium or potassium ions and other charged biomolecules, such as DNA, across ion channels in the cell membrane. Therefore, our approach focused on the direct detection of changes in ion concentrations by utilizing a semiconductor-based biosensor device. Our results demonstrated that our semiconductor-based biosensor platform achieves label-free and noninvasive biosensing that is suitable forin vitrodiagnosis.

scholarly journals Shedding light on melanins within in situ human eye melanocytes using 2-photon microscopy profiling techniques

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ephrem Sitiwin ◽  
Michele C. Madigan ◽  
Enrico Gratton ◽  
Svetlana Cherepanoff ◽  
Robert Max Conway ◽  
...  
Keyword(s):  
Label Free ◽  
Spectral Emission ◽  
Cellular Functions ◽  
Linear Distribution ◽  
Human Eye ◽  
Non Invasive ◽  
Photon Excitation ◽  
Profiling Techniques ◽  
Normal Human

AbstractChoroidal melanocytes (HCMs) are melanin-producing cells in the vascular uvea of the human eye (iris, ciliary body and choroid). These cranial neural crest-derived cells migrate to populate a mesodermal microenvironment, and display cellular functions and extracellular interactions that are biologically distinct to skin melanocytes. HCMs (and melanins) are important in normal human eye physiology with roles including photoprotection, regulation of oxidative damage and immune responses. To extend knowledge of cytoplasmic melanins and melanosomes in label-free HCMs, a non-invasive ‘fit-free’ approach, combining 2-photon excitation fluorescence lifetimes and emission spectral imaging with phasor plot segmentation was applied. Intracellular melanin-mapped FLIM phasors showed a linear distribution indicating that HCM melanins are a ratio of two fluorophores, eumelanin and pheomelanin. A quantitative histogram of HCM melanins was generated by identifying the image pixel fraction contributed by phasor clusters mapped to varying eumelanin/pheomelanin ratio. Eumelanin-enriched dark HCM regions mapped to phasors with shorter lifetimes and longer spectral emission (580–625 nm) and pheomelanin-enriched lighter pigmented HCM regions mapped to phasors with longer lifetimes and shorter spectral emission (550–585 nm). Overall, we demonstrated that these methods can identify and quantitatively profile the heterogeneous eumelanins/pheomelanins within in situ HCMs, and visualize melanosome spatial distributions, not previously reported for these cells.

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