Protein methyl transferases play critical roles in numerous regulatory pathways that underlie cancer development, progression and therapy-response. Here we discuss the function of PRMT5, a member of ...the nine-member PRMT family, in controlling oncogenic processes including tumor intrinsic, as well as extrinsic microenvironmental signaling pathways. We discuss PRMT5 effect on histone methylation and methylation of regulatory proteins including those involved in RNA splicing, cell cycle, cell death and metabolic signaling. In all, we highlight the importance of PRMT5 regulation and function in cancer, which provide the foundation for therapeutic modalities targeting PRMT5.
Accumulating evidence points to an important role for the gut microbiome in anti-tumor immunity. Here, we show that altered intestinal microbiota contributes to anti-tumor immunity, limiting tumor ...expansion. Mice lacking the ubiquitin ligase RNF5 exhibit attenuated activation of the unfolded protein response (UPR) components, which coincides with increased expression of inflammasome components, recruitment and activation of dendritic cells and reduced expression of antimicrobial peptides in intestinal epithelial cells. Reduced UPR expression is also seen in murine and human melanoma tumor specimens that responded to immune checkpoint therapy. Co-housing of Rnf5
and WT mice abolishes the anti-tumor immunity and tumor inhibition phenotype, whereas transfer of 11 bacterial strains, including B. rodentium, enriched in Rnf5
mice, establishes anti-tumor immunity and restricts melanoma growth in germ-free WT mice. Altered UPR signaling, exemplified in Rnf5
mice, coincides with altered gut microbiota composition and anti-tumor immunity to control melanoma growth.
Transparent graphene-based neural electrode arrays provide unique opportunities for simultaneous investigation of electrophysiology, various neural imaging modalities, and optogenetics. Graphene ...electrodes have previously demonstrated greater broad-wavelength transmittance (∼90%) than other transparent materials such as indium tin oxide (∼80%) and ultrathin metals (∼60%). This protocol describes how to fabricate and implant a graphene-based microelectrocorticography (μECoG) electrode array and subsequently use this alongside electrophysiology, fluorescence microscopy, optical coherence tomography (OCT), and optogenetics. Further applications, such as transparent penetrating electrode arrays, multi-electrode electroretinography, and electromyography, are also viable with this technology. The procedures described herein, from the material characterization methods to the optogenetic experiments, can be completed within 3-4 weeks by an experienced graduate student. These protocols should help to expand the boundaries of neurophysiological experimentation, enabling analytical methods that were previously unachievable using opaque metal-based electrode arrays.
Many tumor cells are fueled by altered metabolism and increased glutamine (Gln) dependence. We identify regulation of the L-glutamine carrier proteins SLC1A5 and SLC38A2 (SLC1A5/38A2) by the ...ubiquitin ligase RNF5. Paclitaxel-induced ER stress to breast cancer (BCa) cells promotes RNF5 association, ubiquitination, and degradation of SLC1A5/38A2. This decreases Gln uptake, levels of TCA cycle components, mTOR signaling, and proliferation while increasing autophagy and cell death. Rnf5-deficient MMTV-PyMT mammary tumors were less differentiated and showed elevated SLC1A5 expression. Whereas RNF5 depletion in MDA-MB-231 cells promoted tumorigenesis and abolished paclitaxel responsiveness, SLC1A5/38A2 knockdown elicited opposing effects. Inverse RNF5hi/SLC1A5/38A2lo expression was associated with positive prognosis in BCa. Thus, RNF5 control of Gln uptake underlies BCa response to chemotherapies.
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•Gln carrier proteins SLC1A5 and SLC38A2 are regulated by ubiquitin ligase RNF5•Glutamine uptake and mTOR activity following ERS is RNF5-SLC1A5 dependent•RNF5 inhibition of SLC1A5 is required for paclitaxel-induced apoptosis of BCa cells•Low SLC1A5 expression in BCa TMA and RPPA associates with good prognosis
Jeon et al. show that paclitaxel-induced ER stress in BCa cells promotes the ubiquitin ligase RNF5 to associate with, ubiquitinate, and degrade the Gln carriers SLC1A5 and SLC38A2, thereby leading to decreased Gln uptake and increased autophagy and cell death.
Defining the mechanisms underlying the control of mitochondrial fusion and fission is critical to understanding cellular adaptation to diverse physiological conditions. Here we demonstrate that ...hypoxia induces fission of mitochondrial membranes, dependent on availability of the mitochondrial scaffolding protein AKAP121. AKAP121 controls mitochondria dynamics through PKA-dependent inhibitory phosphorylation of Drp1 and PKA-independent inhibition of Drp1-Fis1 interaction. Reduced availability of AKAP121 by the ubiquitin ligase Siah2 relieves Drp1 inhibition by PKA and increases its interaction with Fis1, resulting in mitochondrial fission. High AKAP121 levels, seen in cells lacking Siah2, attenuate fission and reduce apoptosis of cardiomyocytes under simulated ischemia. Infarct size and degree of cell death were reduced in Siah2−/− mice subjected to myocardial infarction. Inhibition of Siah2 or Drp1 in hatching C. elegans reduces their life span. Through modulating Fis1/Drp1 complex availability, our studies identify Siah2 as a key regulator of hypoxia-induced mitochondrial fission and its physiological significance in ischemic injury and nematode life span.
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► Hypoxia induces Siah2-AKAP121-dependent mitochondrial fission ► PKA-dependent and -independent pathways mediate AKAP121 control of Drp1-Fis1 complex ► Reduced infarct size and apoptosis in Siah2−/− mice subjected to myocardial infarction ► Inhibition of Siah2 or Drp1 in hatching C. elegans shortened life span
Poly(2-acrylamido-2-methylpropane sulfonic acid) is a polyelectrolyte currently used in numerous industrial applications. Herein, we report the use of reversible addition fragmentation chain transfer ...(RAFT) polymerization to prepare a range of well-defined homopolymers and block copolymers of 2-acrylamido-2-methylpropane sulfonic acid (AMPS®) and either N -hydroxyethyl acrylamide (HEAm) or 4-acryloylmorpholine (NAM) as a comonomer. We also describe the one-pot synthesis of multiblock core cross-linked star copolymers of AMPS® and HEAm with low dispersities (<1.3). The influence of several parameters such as the cross-linker type, cross-linker to chain transfer agent (CTA) ratio, arm length and composition on the polymerization efficiency are investigated.
In this work, liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for screening and confirmation of 64 illicit compounds in dietary supplements. The target ...compounds were illegally used pharmaceutical drugs, prohibited compounds, and not authorized ingredients for different therapeutics (sexual enhancement, weight loss, muscular strengthening, and relaxing products). The validation procedure was performed to evaluate selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, and precision according to the Association of Official Analytical Chemists guidelines. The linearity was >0.98 in the range of 0.5-200 µg L
. The LOQs were in the range 1-10 µg kg
for all target compounds. The accuracy (expressed as recovery) was 78.5-114%. The precision (expressed as the relative standard deviation) was below 9.15%. The developed method was applied for the determination of illicit compounds in dietary supplements collected from websites. As a result, the total detection rate was 13.5% (27 samples detected in 200 samples). The concentrations of detected samples ranged from 0.51 to 226 mg g
. The proposed methodology is suitable for monitoring the adulteration of illicit compounds in dietary supplements.
While Rwanda is aiming at environmental pollution resilience and green growth, some industries are still discharging untreated effluent into the environment. This study gives a general overview of ...the compliance level of industrial effluent discharge in Rwanda and the linked negative environmental impacts. It comprises qualitative and quantitative analyses of data obtained from wastewater samples collected from five selected industries in Rwanda. The selected industries had previously been audited and monitored by the Rwanda Environment Management Authority (REMA), due to complains from neighboring residents. The study found that the effluent discharge from wastewater treatment plants (WWTP) for all concerned industries failed to comply with (i) oil and grease (O&G) national and international tolerable parameter limits or the (ii) fecal coliforms national standard. In addition, a compliance level of 66.7% was observed for key water quality monitoring parameters (pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), and heavy metals (i.e., lead (Pb), cadmium (Cd), and chromium (Cr)). Following these study findings, one industry was closed by the REMA for deliberately discharging untreated effluent into an adjacent river. This study recommends the adoption of the best available technology for effluent treatment, installation or renovation of existing WWTPs, and the relocation to industrial zones of industries adjacent to fragile environments.
SHARPIN, an adaptor for the linear ubiquitin chain assembly complex (LUBAC), plays important roles in NF-κB signaling and inflammation. Here, we have demonstrated a LUBAC-independent role for SHARPIN ...in regulating melanoma growth. We observed that SHARPIN interacted with PRMT5, a type II protein arginine methyltransferase, and increased its multiprotein complex and methyltransferase activity. Activated PRMT5 controlled the expression of the transcription factors SOX10 and MITF by SHARPIN-dependent arginine dimethylation and inhibition of the transcriptional corepressor SKI. Activation of PRMT5 by SHARPIN counteracted PRMT5 inhibition by methylthioadenosine, a substrate of methylthioadenosine phosphorylase, which is codeleted with cyclin-dependent kinase inhibitor 2A (CDKN2A) in approximately 15% of human cancers. Collectively, we identified a LUBAC-independent role for SHARPIN in enhancing PRMT5 activity that contributes to melanomagenesis through the SKI/SOX10 regulatory axis.
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