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Proceedings of the National Academy of... Aug 2023To ensure optimal growth, plants actively regulate their growth and development based on environmental changes. Among these, salt stress significantly influences growth...
To ensure optimal growth, plants actively regulate their growth and development based on environmental changes. Among these, salt stress significantly influences growth and yield. In this study, we demonstrate that the growth of root hairs of salt-stressed seedlings is regulated by the SALT OVERLY SENSITIVE 2 (SOS2)-GUANOSINE NUCLEOTIDE DIPHOSPHATE DISSOCIATION INHIBITOR 1 (RhoGDI1)-Rho GTPASE OF PLANTS 2 (ROP2) module. We show here that the kinase SOS2 is activated by salt stress and subsequently phosphorylates RhoGDI1, a root hair regulator, thereby decreasing its stability. This change in RhoGDI1 abundance resulted in a fine-tuning of polar localization of ROP2 and root hair initiation followed by polar growth, demonstrating how SOS2-regulated root hair development is critical for plant growth under salt stress. Our results reveal how a tissue-specific response to salt stress balances the relationship of salt resistance and basic growth.
Topics: rho Guanine Nucleotide Dissociation Inhibitor alpha; Arabidopsis; Phosphorylation; Guanosine Diphosphate; Salt Stress
PubMed: 37590409
DOI: 10.1073/pnas.2217957120 -
Cell Dec 2023Transfer RNA (tRNA) modifications are critical for protein synthesis. Queuosine (Q), a 7-deaza-guanosine derivative, is present in tRNA anticodons. In vertebrate tRNAs...
Transfer RNA (tRNA) modifications are critical for protein synthesis. Queuosine (Q), a 7-deaza-guanosine derivative, is present in tRNA anticodons. In vertebrate tRNAs for Tyr and Asp, Q is further glycosylated with galactose and mannose to generate galQ and manQ, respectively. However, biogenesis and physiological relevance of Q-glycosylation remain poorly understood. Here, we biochemically identified two RNA glycosylases, QTGAL and QTMAN, and successfully reconstituted Q-glycosylation of tRNAs using nucleotide diphosphate sugars. Ribosome profiling of knockout cells revealed that Q-glycosylation slowed down elongation at cognate codons, UAC and GAC (GAU), respectively. We also found that galactosylation of Q suppresses stop codon readthrough. Moreover, protein aggregates increased in cells lacking Q-glycosylation, indicating that Q-glycosylation contributes to proteostasis. Cryo-EM of human ribosome-tRNA complex revealed the molecular basis of codon recognition regulated by Q-glycosylations. Furthermore, zebrafish qtgal and qtman knockout lines displayed shortened body length, implying that Q-glycosylation is required for post-embryonic growth in vertebrates.
Topics: Animals; Humans; Rats; Anticodon; Cell Line; Codon; Glycosylation; Nucleoside Q; RNA, Transfer; Swine; Zebrafish; Nucleic Acid Conformation
PubMed: 37992713
DOI: 10.1016/j.cell.2023.10.026 -
Oncology Reports Nov 2023Kirsten rat sarcoma viral oncogene homolog () is one of the most frequently mutated oncogenes in solid tumors. More than 90% of pancreatic ductal adenocarcinoma (PDAC)... (Review)
Review
Kirsten rat sarcoma viral oncogene homolog () is one of the most frequently mutated oncogenes in solid tumors. More than 90% of pancreatic ductal adenocarcinoma (PDAC) are driven by mutations in the gene, suggesting the importance of targeting this oncogene in PDAC. Initial efforts to target KRAS have been unsuccessful due to its small size, high affinity for guanosine triphosphate/guanosine diphosphate, and lack of distinct drug‑binding pockets. Therefore, much of the focus has been directed at inhibiting the activation of major signaling pathways downstream of KRAS, most notably the PI3K/AKT and RAF/MAPK pathways, using tyrosine kinase inhibitors and monoclonal antibodies. While preclinical studies showed promising results, clinical data using the inhibitors alone and in combination with other standard therapies have shown limited practicality, largely due to the lack of efficacy and dose‑limiting toxicities. Recent therapeutic approaches for KRAS‑driven tumors focus on mutation‑specific drugs such as selective inhibitors and son of sevenless 1 pan‑KRAS inhibitors. While inhibitors showed great promise against patients with non‑small cell lung cancer (NSCLC) harboring mutations, they were not efficacious in PDAC largely because the major mutant isoforms in PDAC are G12D, G12V, and G12R. As a result, and pan‑KRAS inhibitors are currently under investigation as potential therapeutic options for PDAC. The present review summarized the importance of KRAS oncogenic signaling, challenges in its targeting, and preclinical and clinical targeted agents including recent direct KRAS inhibitors for blocking KRAS signaling in PDAC.
Topics: Humans; Proto-Oncogene Proteins p21(ras); Phosphatidylinositol 3-Kinases; Carcinoma, Non-Small-Cell Lung; Lung Neoplasms; Pancreatic Neoplasms; Carcinoma, Pancreatic Ductal; Mutation
PubMed: 37800636
DOI: 10.3892/or.2023.8643 -
Molecular Cell Jul 2023Modification of nucleic acids by ADP-ribosylation is catalyzed by various ADP-ribosyltransferases, including the DarT enzyme. The latter is part of the bacterial...
Modification of nucleic acids by ADP-ribosylation is catalyzed by various ADP-ribosyltransferases, including the DarT enzyme. The latter is part of the bacterial toxin-antitoxin (TA) system DarTG, which was shown to provide control of DNA replication and bacterial growth as well as protection against bacteriophages. Two subfamilies have been identified, DarTG1 and DarTG2, which are distinguished by their associated antitoxins. While DarTG2 catalyzes reversible ADP-ribosylation of thymidine bases employing a macrodomain as antitoxin, the DNA ADP-ribosylation activity of DarTG1 and the biochemical function of its antitoxin, a NADAR domain, are as yet unknown. Using structural and biochemical approaches, we show that DarT1-NADAR is a TA system for reversible ADP-ribosylation of guanosine bases. DarT1 evolved the ability to link ADP-ribose to the guanine amino group, which is specifically hydrolyzed by NADAR. We show that guanine de-ADP-ribosylation is also conserved among eukaryotic and non-DarT-associated NADAR members, indicating a wide distribution of reversible guanine modifications beyond DarTG systems.
Topics: Guanosine; ADP-Ribosylation; ADP Ribose Transferases; Eukaryotic Cells; Antitoxins; Adenosine Diphosphate Ribose
PubMed: 37390817
DOI: 10.1016/j.molcel.2023.06.013 -
Autophagy Apr 2024RAB37 GTPase regulates cargo exocytosis by cycling between an inactive GDP-bound form and an active GTP-bound form. We reveal that RAB37 simultaneously regulates...
RAB37 GTPase regulates cargo exocytosis by cycling between an inactive GDP-bound form and an active GTP-bound form. We reveal that RAB37 simultaneously regulates autophagy activation and tissue inhibitor of metalloproteinase 1 (TIMP1) secretion in lung cancer cells under starvation conditions. TIMP1, an inflammatory cytokine, is a known inhibitory molecule of matrix metalloproteinases matrix metalloproteinase 9 and suppresses the mobility of lung cancer cells both in vitro and in vivo through conventional exocytosis under serum-free conditions. Notably, we disclosed that secretory autophagy participates in TIMP1 secretion in a RAB37- and Sec22b-dependent manner. Sec22b, a SNARE family protein, participates in vesicle and membrane fusion of secretory autophagy. Knockdown of Sec22b decreased TIMP1 secretion and cell motility but did not affect cell proliferation under starvation conditions. We confirmed that starvation-activated RAB37 accompanied by Sec22b is essential for secretory autophagy to further enhance TIMP1 exocytosis. We further use an off-label drug amiodarone to demonstrate that autophagy induction facilitates TIMP1 secretion and suppresses the motility and metastasis of lung cancer cells in a RAB37-dependent manner in the lung-to-lung mouse model. In conclusion, we demonstrated that the RAB37 activation plays a pivotal regulatory role in secretory autophagy for TIMP1 secretion in lung cancer. ATG: autophagy-related gene; GDP: guanosine diphosphate; GTP: guanosine triphosphate; LC3: microtubule-associated protein 1A/1B-light chain 3; SNARE: soluble N-ethylmaleimide-sensitive-factor attachment protein receptor; TIMP1: tissue inhibitor matrix metalloproteinase 1.
Topics: Animals; Humans; Mice; Autophagy; Cell Line, Tumor; Cell Movement; Cell Proliferation; Exocytosis; Lung Neoplasms; rab GTP-Binding Proteins; Tissue Inhibitor of Metalloproteinase-1
PubMed: 37151129
DOI: 10.1080/15548627.2023.2210446 -
Cancer Metastasis Reviews Dec 2023Metastatic progression is regulated by metastasis promoter and suppressor genes. NME1, the prototypic and first described metastasis suppressor gene, encodes a... (Review)
Review
Metastatic progression is regulated by metastasis promoter and suppressor genes. NME1, the prototypic and first described metastasis suppressor gene, encodes a nucleoside diphosphate kinase (NDPK) involved in nucleotide metabolism; two related family members, NME2 and NME4, are also reported as metastasis suppressors. These proteins physically interact with members of the GTPase dynamin family, which have key functions in membrane fission and fusion reactions necessary for endocytosis and mitochondrial dynamics. Evidence supports a model in which NDPKs provide GTP to dynamins to maintain a high local GTP concentration for optimal dynamin function. NME1 and NME2 are cytosolic enzymes that provide GTP to dynamins at the plasma membrane, which drive endocytosis, suggesting that these NMEs are necessary to attenuate signaling by receptors on the cell surface. Disruption of NDPK activity in NME-deficient tumors may thus drive metastasis by prolonging signaling. NME4 is a mitochondrial enzyme that interacts with the dynamin OPA1 at the mitochondria inner membrane to drive inner membrane fusion and maintain a fused mitochondrial network. This function is consistent with the current view that mitochondrial fusion inhibits the metastatic potential of tumor cells whereas mitochondrial fission promotes metastasis progression. The roles of NME family members in dynamin-mediated endocytosis and mitochondrial dynamics and the intimate link between these processes and metastasis provide a new framework to understand the metastasis suppressor functions of NME proteins.
Topics: Humans; NM23 Nucleoside Diphosphate Kinases; Dynamins; Neoplasms; Cell Membrane; Guanosine Triphosphate
PubMed: 37353690
DOI: 10.1007/s10555-023-10118-x -
Clinical and Translational Science Dec 2023Vericiguat, a novel soluble guanylate cyclase (sGC) stimulator, is approved for the treatment of heart failure (HF) with reduced ejection fraction (HFrEF). Decreased... (Review)
Review
Vericiguat, a novel soluble guanylate cyclase (sGC) stimulator, is approved for the treatment of heart failure (HF) with reduced ejection fraction (HFrEF). Decreased nitric oxide (NO) availability, sGC desensitization to NO, sGC deficiency, and reduced cyclic guanosine monophosphate (cGMP) signaling are potential contributing factors for HF disease progression. Vericiguat works via stimulation of sGC in the critical NO-sGC-cGMP pathway. Vericiguat is primarily metabolized by glucuronidation via uridine diphosphate-glucuronosyltransferase (UGT) isoforms UGT1A1 and UGT1A9. Urinary excretion and renal clearance of vericiguat are low. No intrinsic factor had a clinically relevant effect on vericiguat exposure. Vericiguat has low drug-drug interaction potential with no clinically relevant pharmacokinetic or pharmacodynamic interactions observed with warfarin, digoxin, aspirin, or sacubitril/valsartan. The global phase III study VICTORIA included patients with HFrEF who had a recent HF hospitalization or intravenous diuretic treatment for HF. Treatment with vericiguat on top of standard of care resulted in a 10% relative reduction in the primary composite outcome of death from cardiovascular causes or first hospitalization for HF. Vericiguat was well-tolerated with low incidence of symptomatic hypotension and syncope compared to placebo. Given its positive benefit-risk profile, vericiguat is an important option for high-risk patients with HFrEF who are already on guideline-directed medical therapy and had recent worsening of HF. Future efforts to develop additional effective therapies are needed to further reduce morbidity and mortality in patients with HF.
Topics: Humans; Heart Failure; Treatment Outcome; Translational Science, Biomedical; Stroke Volume; Vasodilator Agents
PubMed: 37997225
DOI: 10.1111/cts.13677 -
Medicina (Kaunas, Lithuania) Dec 2023: To identify the most frequently reported predictive factors for the persistency of pregnancy-related pelvic girdle pain (PPGP) at 3-6 months after childbirth in women... (Meta-Analysis)
Meta-Analysis Review
: To identify the most frequently reported predictive factors for the persistency of pregnancy-related pelvic girdle pain (PPGP) at 3-6 months after childbirth in women with PPGP alone or PPGP in association with pregnancy-related lower back pain (PLBP). : Eligibility criteria: Two authors independently selected studies excluding PPGP determined by a specific, traumatic, gynecological/urological cause or isolated PLBP and studies that did not include the presence/absence of PPGP as the the primary outcome. We, instead, included studies with an initial assessment in pregnancy (within 1 month of delivery) and with a follow-up of at least 3 months after delivery. : The research was performed using the databases of Medline, Cochrane, Pedro, Scopus, Web of Science and Cinahl from December 2018 to January 2022, following the indications of the PRISMA statement 2021 and the MOOSE checklist. It includes observational cohort studies in which data were often collected through prospective questionnaires (all in English). : Two independent authors performed evaluations of the risk of bias (ROB) using the quality in prognostic studies (QUIPS) tool. : An in-depth qualitative analysis was conducted because, due to a high degree of heterogeneity in the data collection of the included studies and a lack of raw data suitable for quantitative analysis, it was not possible to carry out the originally planned meta-analyses for the subgroups. : The research process led to the inclusion of 10 articles which were evaluated using the QUIPS tool: 5 studies were evaluated as low ROB and 5 were evaluated as moderate ROB. High levels of pain in pregnancy, a large number of positive provocation tests, a history of lower back pain and lumbo-pelvic pain, high levels of disability in pregnancy, neurotic behavior and high levels of fear-avoidance belief were identified as strong predictors of long-term PPGP, while there was weak or contradictory evidence regarding predictions of emotional distress, catastrophizing and sleep disturbances. : The impossibility of carrying out the meta-analysis by subgroups suggests the need for further research with greater methodological rigor in the acquisition of measures based on an already existing PPGP core predictors/outcome sets.
Topics: Pregnancy; Humans; Female; Pelvic Girdle Pain; Low Back Pain; Prospective Studies; Pregnancy Complications; Surveys and Questionnaires
PubMed: 38138226
DOI: 10.3390/medicina59122123 -
Redox Biology Oct 2023Enhancing energy turnover via uncoupled mitochondrial respiration in adipose tissue has great potential to improve human obesity and other metabolic complications....
OBJECTIVE
Enhancing energy turnover via uncoupled mitochondrial respiration in adipose tissue has great potential to improve human obesity and other metabolic complications. However, the amount of human brown adipose tissue and its uncoupling protein 1 (UCP1) is low in obese patients. Recently, a class of endogenous molecules, N-acyl amino acids (NAAs), was identified as mitochondrial uncouplers in murine adipocytes, presumably acting via the adenine nucleotide translocator (ANT). Given the translational potential, we investigated the bioenergetic effects of NAAs in human adipocytes, characterizing beneficial and adverse effects, dose ranges, amino acid derivatives and underlying mechanisms.
METHOD
NAAs with neutral (phenylalanine, leucine, isoleucine) and polar (lysine) residues were synthetized and assessed in intact and permeabilized human adipocytes using plate-based respirometry. The Seahorse technology was applied to measure bioenergetic parameters, dose-dependency, interference with UCP1 and adenine nucleotide translocase (ANT) activity, as well as differences to the established chemical uncouplers niclosamide ethanolamine (NEN) and 2,4-dinitrophenol (DNP).
RESULT
NAAs with neutral amino acid residues potently induce uncoupled respiration in human adipocytes in a dose-dependent manner, even in the presence of the UCP1-inhibitor guanosine diphosphate (GDP) and the ANT-inhibitor carboxyatractylate (CAT). However, neutral NAAs significantly reduce maximal oxidation rates, mitochondrial ATP-production, coupling efficiency and reduce adipocyte viability at concentrations above 25 μM. The in vitro therapeutic index (using induced proton leak and viability as determinants) of NAAs is lower than that of NEN and DNP.
CONCLUSION
NAAs are potent mitochondrial uncouplers in human adipocytes, independent of UCP1 and ANT. However, previously unnoticed adverse effects harm adipocyte functionality, reduce the therapeutic index of NAAs in vitro and therefore question their suitability as anti-obesity agents without further chemical modifications.
Topics: Humans; Animals; Mice; Amino Acids; Adipocytes; Ethanolamine; Adipose Tissue, Brown; Energy Metabolism
PubMed: 37683300
DOI: 10.1016/j.redox.2023.102874 -
Nature May 2024The µ-opioid receptor (µOR) is an important target for pain management and molecular understanding of drug action on µOR will facilitate the development of better...
The µ-opioid receptor (µOR) is an important target for pain management and molecular understanding of drug action on µOR will facilitate the development of better therapeutics. Here we show, using double electron-electron resonance and single-molecule fluorescence resonance energy transfer, how ligand-specific conformational changes of µOR translate into a broad range of intrinsic efficacies at the transducer level. We identify several conformations of the cytoplasmic face of the receptor that interconvert on different timescales, including a pre-activated conformation that is capable of G-protein binding, and a fully activated conformation that markedly reduces GDP affinity within the ternary complex. Interaction of β-arrestin-1 with the μOR core binding site appears less specific and occurs with much lower affinity than binding of G.
Topics: Receptors, Opioid, mu; Ligands; Fluorescence Resonance Energy Transfer; Humans; Protein Conformation; beta-Arrestins; Binding Sites; Guanosine Diphosphate; Single Molecule Imaging; Models, Molecular; Protein Binding; GTP-Binding Protein alpha Subunits, Gi-Go; Animals
PubMed: 38600384
DOI: 10.1038/s41586-024-07295-2