Fluorescent probes for in vivo redox potential measurement and thiol rich protein function

AbstractEmerging evidence has demonstrated that alternative splicing has a vital role in regulating protein function, but how alternative splicing factors can be regulated remains unclear. We showed that the PPM1G, a protein phosphatase, regulated the phosphorylation of SRSF3 in hepatocellular carcinoma (HCC) and contributed to the proliferation, invasion, and metastasis of HCC. PPM1G was highly expressed in HCC tissues compared to adjacent normal tissues, and higher levels of PPM1G were observed in adverse staged HCCs. The higher levels of PPM1G were highly correlated with poor prognosis, which was further validated in the TCGA cohort. The knockdown of PPM1G inhibited the cell growth and invasion of HCC cell lines. Further studies showed that the knockdown of PPM1G inhibited tumor growth in vivo. The mechanistic analysis showed that the PPM1G interacted with proteins related to alternative splicing, including SRSF3. Overexpression of PPM1G promoted the dephosphorylation of SRSF3 and changed the alternative splicing patterns of genes related to the cell cycle, the transcriptional regulation in HCC cells. In addition, we also demonstrated that the promoter of PPM1G was activated by multiple transcription factors and co-activators, including MYC/MAX and EP300, MED1, and ELF1. Our study highlighted the essential role of PPM1G in HCC and shed new light on unveiling the regulation of alternative splicing in malignant transformation.

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Important Role for Phylogenetically Invariant PP2Acα Active Site and C-Terminal Residues Revealed by Mutational Analysis in Saccharomyces cerevisiae

Genetics ◽

10.1093/genetics/156.1.21 ◽

2000 ◽

Vol 156 (1) ◽

pp. 21-29 ◽

Cited By ~ 1

Author(s):

David R H Evans ◽

Brian A Hemmings

Keyword(s):

Protein Interactions ◽

Active Site ◽

Protein Function ◽

Mutational Analysis ◽

Yeast Cells ◽

Temperature Sensitive ◽

Active Site Residues ◽

Catalytic Function

Abstract PP2A is a central regulator of eukaryotic signal transduction. The human catalytic subunit PP2Acα functionally replaces the endogenous yeast enzyme, Pph22p, indicating a conservation of function in vivo. Therefore, yeast cells were employed to explore the role of invariant PP2Ac residues. The PP2Acα Y127N substitution abolished essential PP2Ac function in vivo and impaired catalysis severely in vitro, consistent with the prediction from structural studies that Tyr-127 mediates substrate binding and its side chain interacts with the key active site residues His-118 and Asp-88. The V159E substitution similarly impaired PP2Acα catalysis profoundly and may cause global disruption of the active site. Two conditional mutations in the yeast Pph22p protein, F232S and P240H, were found to cause temperature-sensitive impairment of PP2Ac catalytic function in vitro. Thus, the mitotic and cell lysis defects conferred by these mutations result from a loss of PP2Ac enzyme activity. Substitution of the PP2Acα C-terminal Tyr-307 residue by phenylalanine impaired protein function, whereas the Y307D and T304D substitutions abolished essential function in vivo. Nevertheless, Y307D did not reduce PP2Acα catalytic activity significantly in vitro, consistent with an important role for the C terminus in mediating essential protein-protein interactions. Our results identify key residues important for PP2Ac function and characterize new reagents for the study of PP2A in vivo.

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A study of deregulated MMR pathways and anticancer potential of curcuma derivatives using computational approach

Scientific Reports ◽

10.1038/s41598-021-89282-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Priyanjali Bhattacharya ◽

Trupti N. Patel

Keyword(s):

Mismatch Repair ◽

Protein Function ◽

Curcuma Longa ◽

Signaling Cascades ◽

Altered Expression ◽

Anticancer Properties ◽

Medicinal Properties ◽

Multiple Signaling

AbstractPlant derived products have steadily gained momentum in treatment of cancer over the past decades. Curcuma and its derivatives, in particular, have diverse medicinal properties including anticancer potential with proven safety as supported by numerous in vivo and in vitro studies. A defective Mis-Match Repair (MMR) is implicated in solid tumors but its role in haematologic malignancies is not keenly studied and the current literature suggests that it is limited. Nonetheless, there are multiple pathways interjecting the mismatch repair proteins in haematologic cancers that may have a direct or indirect implication in progression of the disease. Here, through computational analysis, we target proteins that are involved in rewiring of multiple signaling cascades via altered expression in cancer using various curcuma derivatives (Curcuma longa L. and Curcuma caesia Roxb.) which in turn, profoundly controls MMR protein function. These biomolecules were screened to identify their efficacy on selected targets (in blood-related cancers); aberrations of which adversely impacted mismatch repair machinery. The study revealed that of the 536 compounds screened, six of them may have the potential to regulate the expression of identified targets and thus revive the MMR function preventing genomic instability. These results reveal that there may be potential plant derived biomolecules that may have anticancer properties against the tumors driven by deregulated MMR-pathways.

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Polarity-active NIR probes with strong two-photon absorption and ultrahigh binding affinity of insulin amyloid fibrils

Chemical Science ◽

10.1039/d0sc03907a ◽

2021 ◽

Author(s):

Li Li ◽

Zheng Lv ◽

Zhongwei Man ◽

Zhenzhen Xu ◽

YuLing Wei ◽

...

Keyword(s):

Neurodegenerative Diseases ◽

Binding Affinity ◽

Fluorescent Probes ◽

Amyloid Fibrils ◽

Photon Absorption ◽

Two Photon Absorption ◽

Two Photon ◽

Medical Diagnostic

Amyloid fibrils are associated with many neurodegenerative diseases. In-situ and in-vivo visualization of amyloid fibrils is important for medical diagnostic and requires fluorescent probes with both excitation and emission wavelengths in...

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Insulin amyloid polymorphs: implications for iatrogenic cytotoxicity

RSC Advances ◽

10.1039/d0ra07742a ◽

2020 ◽

Vol 10 (62) ◽

pp. 37721-37727 ◽

Cited By ~ 1

Author(s):

Keisuke Yuzu ◽

Mikael Lindgren ◽

Sofie Nyström ◽

Jun Zhang ◽

Wakako Mori ◽

...

Keyword(s):

Fluorescent Probes ◽

Structural Polymorphism

Structural polymorphism of insulin amyloids in vivo can be recognized using novel amyloid specific fluorescent probes, pFTAA and BTD21.

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Biological nanoscale fluorescent probes: From structure and performance to bioimaging

Reviews in Analytical Chemistry ◽

10.1515/revac-2020-0119 ◽

2020 ◽

Vol 39 (1) ◽

pp. 209-221

Author(s):

Jiafeng Wan ◽

Xiaoyuan Zhang ◽

Kai Zhang ◽

Zhiqiang Su

Keyword(s):

Fluorescent Probes ◽

Organic Dyes ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

High Sensitivity ◽

Biological Imaging ◽

Fluorescent Materials ◽

And Performance

Abstract In recent years, nanomaterials have attracted lots of attention from researchers due to their unique properties. Nanometer fluorescent materials, such as organic dyes, semiconductor quantum dots (QDs), metal nano-clusters (MNCs), carbon dots (CDs), etc., are widely used in biological imaging due to their high sensitivity, short response time, and excellent accuracy. Nanometer fluorescent probes can not only perform in vitro imaging of organisms but also achieve in vivo imaging. This provides medical staff with great convenience in cancer treatment. Combined with contemporary medical methods, faster and more effective treatment of cancer is achievable. This article explains the response mechanism of three-nanometer fluorescent probes: the principle of induced electron transfer (PET), the principle of fluorescence resonance energy transfer (FRET), and the principle of intramolecular charge transfer (ICT), showing the semiconductor QDs, precious MNCs, and CDs. The excellent performance of the three kinds of nano fluorescent materials in biological imaging is highlighted, and the application of these three kinds of nano fluorescent probes in targeted biological imaging is also introduced. Nanometer fluorescent materials will show their significance in the field of biomedicine.

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In vivo visualization of osteoarthritic hypertrophic lesions

Chemical Science ◽

10.1039/c5sc01301a ◽

2015 ◽

Vol 6 (11) ◽

pp. 6256-6261 ◽

Cited By ~ 13

Author(s):

Hai-Yu Hu ◽

Ngee-Han Lim ◽

Hans-Paul Juretschke ◽

Danping Ding-Pfennigdorff ◽

Peter Florian ◽

...

Keyword(s):

Animal Models ◽

Fluorescent Probes

Cartilage-binding bimodal MRI and fluorescent probes were developed to monitor osteoarthritic damage in animal models over extended periods of time.

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Sirtuin-dependent reversible lysine acetylation controls the activity of acetyl-Coenzyme A synthetase in Campylobacter jejuni

Journal of Bacteriology ◽

10.1128/jb.00333-21 ◽

2021 ◽

Author(s):

Victoria L. Jeter ◽

Jorge C. Escalante-Semerena

Keyword(s):

Campylobacter Jejuni ◽

Posttranslational Modifications ◽

Active Site ◽

Protein Function ◽

Metabolic Enzyme ◽

Lysine Acetylation ◽

Class Iii ◽

Acetyl Coa

Posttranslational modifications are mechanisms for rapid control of protein function used by cells from all domains of life. Acetylation of the epsilon amino group ( N ε ) of an active-site lysine of the AMP-forming acetyl-CoA synthetase (Acs) enzyme is the paradigm for the posttranslational control of the activity of metabolic enzymes. In bacteria, the alluded active-site lysine of Acs enzymes can be modified by a number of different GCN5-type N -acetyltransferases (GNATs). Acs activity is lost as a result of acetylation, and restored by deacetylation. Using a heterologous host, we show that Campylobacter jejuni NCTC11168 synthesizes enzymes that control Acs function by reversible lysine acetylation (RLA). This work validates the function of gene products encoded by the cj1537c , cj1715, and cj1050c loci, namely the AMP-forming acetate:CoA ligase ( Cj Acs), a type IV GCN5-type lysine acetyltransferase (GNAT, hereafter Cj LatA), and a NAD + -dependent (class III) sirtuin deacylase ( Cj CobB), respectively. To our knowledge, these are the first in vivo and in vitro data on C. jejuni enzymes that control the activity of Cj Acs. IMPORTANCE This work is important because it provides the experimental evidence needed to support the assignment of function to three key enzymes, two of which control the reversible posttranslational modification of an active-site lysyl residue of the central metabolic enzyme acetyl-CoA synthetase ( Cj Acs). We can now generate Campylobacter jejuni mutant strains defective in these functions, so we can establish the conditions in which this mode of regulation of Cj Acs is triggered in this bacterium. Such knowledge may provide new therapeutic strategies for the control of this pathogen.

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Discs large 1 controls daughter-cell polarity after cytokinesis in vertebrate morphogenesis

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1713959115 ◽

2018 ◽

Vol 115 (46) ◽

pp. E10859-E10868 ◽

Cited By ~ 5

Author(s):

Yuwei Li ◽

Jason A. Junge ◽

Cosimo Arnesano ◽

Garrett G. Gross ◽

Jeffrey H. Miner ◽

...

Keyword(s):

Cell Polarity ◽

Protein Interactions ◽

Protein Function ◽

Resonance Energy Transfer ◽

Resonance Energy ◽

Explant Culture ◽

Scaffolding Protein ◽

Fluorescence Lifetime Imaging ◽

Discs Large

Vertebrate embryogenesis and organogenesis are driven by cell biological processes, ranging from mitosis and migration to changes in cell size and polarity, but their control and causal relationships are not fully defined. Here, we use the developing limb skeleton to better define the relationships between mitosis and cell polarity. We combine protein-tagging and -perturbation reagents with advanced in vivo imaging to assess the role of Discs large 1 (Dlg1), a membrane-associated scaffolding protein, in mediating the spatiotemporal relationship between cytokinesis and cell polarity. Our results reveal that Dlg1 is enriched at the midbody during cytokinesis and that its multimerization is essential for the normal polarity of daughter cells. Defects in this process alter tissue dimensions without impacting other cellular processes. Our results extend the conventional view that division orientation is established at metaphase and anaphase and suggest that multiple mechanisms act at distinct phases of the cell cycle to transmit cell polarity. The approach employed can be used in other systems, as it offers a robust means to follow and to eliminate protein function and extends the Phasor approach for studying in vivo protein interactions by frequency-domain fluorescence lifetime imaging microscopy of Förster resonance energy transfer (FLIM-FRET) to organotypic explant culture.

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