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Planta Jun 2021OsJAZ11 regulates phosphate homeostasis by suppressing jasmonic acid signaling and biosynthesis in rice roots. Jasmonic Acid (JA) is a key plant signaling molecule which...
OsJAZ11 regulates phosphate homeostasis by suppressing jasmonic acid signaling and biosynthesis in rice roots. Jasmonic Acid (JA) is a key plant signaling molecule which negatively regulates growth processes including root elongation. JAZ (JASMONATE ZIM-DOMAIN) proteins function as transcriptional repressors of JA signaling. Therefore, targeting JA signaling by deploying JAZ repressors may enhance root length in crops. In this study, we overexpressed JAZ repressor OsJAZ11 in rice to alleviate the root growth inhibitory action of JA. OsJAZ11 is a low phosphate (Pi) responsive gene which is transcriptionally regulated by OsPHR2. We report that OsJAZ11 overexpression promoted primary and seminal root elongation which enhanced Pi foraging. Expression studies revealed that overexpression of OsJAZ11 also reduced Pi starvation response (PSR) under Pi limiting conditions. Moreover, OsJAZ11 overexpression also suppressed JA signaling and biosynthesis as compared to wild type (WT). We further demonstrated that the C-terminal region of OsJAZ11 was crucial for stimulating root elongation in overexpression lines. Rice transgenics overexpressing truncated OsJAZ11ΔC transgene (i.e., missing C-terminal region) exhibited reduced root length and Pi uptake. Interestingly, OsJAZ11 also regulates Pi homeostasis via physical interaction with a key Pi sensing protein, OsSPX1. Our study highlights the functional connections between JA and Pi signaling and reveals JAZ repressors as a promising candidate for improving low Pi tolerance of elite rice genotypes.
Topics: Cyclopentanes; Gene Expression Regulation, Plant; Oryza; Oxylipins; Phosphates; Plant Proteins; Plants, Genetically Modified
PubMed: 34143292
DOI: 10.1007/s00425-021-03657-6 -
International Journal of Molecular... Mar 2022Spliced X‑box binding protein 1 (XBP1s) has been reported to participate in the pathogenesis of numerous types of cancer; however, whether XBP1s plays a role in lung...
Spliced X‑box binding protein 1 (XBP1s) has been reported to participate in the pathogenesis of numerous types of cancer; however, whether XBP1s plays a role in lung cancer remains to be elucidated. In the present study, bioinformatics analysis was performed to determine the mRNA expression level of XBP1 in lung cancer and adjacent normal tissues. Gene Ontology terms, pathway enrichment and Pearson's correlation analysis were performed to investigate the possible mechanism involved. Western blot and reverse transcription‑quantitative PCR were performed to quantify the protein and mRNA expression level of target proteins, respectively. Small interfering RNA or overexpression plasmid were used to knockdown or overexpress the expression level of XBP1s. EdU staining, colony formation, Cell Counting Kit‑8, Transwell and wound healing assays, and flow cytometry were performed to detect the proliferation, colony forming ability, cell viability, migration and invasion ability, and the apoptosis rate. The results showed that the mRNA and protein expression level of XBP1 was higher in tumor tissues compared with that in adjacent normal tissues using data from the TIMER2.0, ONCOMINE and UALCAN online databases. In addition, the mRNA expression level of XBP1 was also associated with clinical features, including age, smoking habit, individual cancer stage and nodal metastasis status. In the experiments, the mRNA and protein expression level of XBP1s was increased in the A549 cell line compared with that in the human bronchial epithelial (HBE), H1299, PC9 and H460 cell lines. Hypoxia further increased the protein expression level of XBP1s in the A549 cell line. Knockdown of XBP1s expression in the A549 cell line resulted in decreased proliferation, colony formation, cell viability, migration and invasion, and increased apoptosis. By contrast, overexpressing XBP1s in the HBE cell line led to the opposite results. To investigate the mechanism involved, proteins associated with XBP1 were analyzed using the LinkedOmics database. Pathway enrichment revealed the MAPK pathway to be the possible XBP1 downstream target. Furthermore, Pearson's correlation and western blot analyses verified that phosphorylated (p)‑JNK rather than p‑ERK or p‑p38 was the downstream effector of XBP1s. Phosphorylation of JNK was decreased when XBP1s expression was knocked down in the A549 cell line under normoxic and hypoxic conditions. Inhibiting p‑JNK with SP600125 reversed the increased prosurvival effects caused by XBP1s overexpression. The results from the present study suggest that XBP1s/p‑JNK function as a prosurvival factors in the A549 cell line and could be a potential target for the treatment of lung adenocarcinoma.
Topics: Adenocarcinoma of Lung; Cell Line, Tumor; Cell Movement; Cell Proliferation; Gene Expression Regulation, Neoplastic; Humans; Lung Neoplasms; MAP Kinase Signaling System; X-Box Binding Protein 1
PubMed: 35059734
DOI: 10.3892/ijmm.2022.5089 -
International Review of Cell and... 2022Mertk, a type I Receptor Tyrosine Kinase (RTK) and member of the TAM (Tyro3, Axl, and Mertk) family of homologous tyrosine kinases, has important roles in signal...
Mertk, a type I Receptor Tyrosine Kinase (RTK) and member of the TAM (Tyro3, Axl, and Mertk) family of homologous tyrosine kinases, has important roles in signal transduction both homeostatically on normal cells as well as patho-physiologically on both tumor-associated macrophages and malignant cells by its overexpression in a wide array of cancers. The main ligands of Mertk are Vitamin K-modified endogenous proteins Gas6 and Protein S (ProS1), heterobifunctional modular proteins that bind Mertk via two carboxyl-terminal laminin-like globular (LG) domains, and an N-terminal Gla domain that binds anionic phospholipids, whereby externalized phosphatidylserine (PS) on stressed viable and caspase-activated apoptotic cells is most emblematic. Recent studies indicate that Vitamin K-dependent γ-carboxylation on the N-terminal Gla domain of Gas6 and Protein S is necessary for PS binding and Mertk activation, implying that Mertk is preferentially active in tissues where there is high externalized PS, such as the tumor microenvironment (TME) and acute virally infected tissues. Once stimulated, activated Mertk can provide a survival advantage for cancer cells as well as drive compensatory proliferation. On monocytes and tumor-associated macrophages, Mertk promotes efferocytosis and acts as an inhibitory receptor that impairs host anti-tumor immunity, functioning akin to a myeloid checkpoint inhibitor. In recent years, inhibition of Mertk has been implicated in a dual role to enhance the sensitivity of cancer cells to cytotoxic agents along with improving host anti-tumor immunity with anti-PD-1/PD-L1 immunotherapy. Here, we examine the rationale of Mertk-targeted immunotherapies, the current and potential therapeutic strategies, the clinical status of Mertk-specific therapies, and potential challenges and obstacles for Mertk-focused therapies.
Topics: Biology; Humans; Neoplasms; Protein S; Proto-Oncogene Proteins; Tumor Microenvironment; Vitamin K; c-Mer Tyrosine Kinase
PubMed: 35636929
DOI: 10.1016/bs.ircmb.2022.04.004 -
Frontiers in Endocrinology 2021The Iroquois homeobox 3 () gene was recently reported to be a functional downstream target of a common polymorphism in the gene, which encodes an obesity-associated...
OBJECTIVE
The Iroquois homeobox 3 () gene was recently reported to be a functional downstream target of a common polymorphism in the gene, which encodes an obesity-associated protein; however, the role of in energy expenditure remains unclear. Studies have revealed that the overexpression of a dominant-negative form of IRX3 in the mouse hypothalamus and adipose tissue promoted energy expenditure by enhancing brown/browning activities. Meanwhile, we and others recently demonstrated that knockdown impaired the browning program of primary preadipocytes . In this study, we aimed to further clarify the effects of overexpressing human (h) on brown/beige adipose tissues .
METHODS
Brown/beige adipocyte-specific h-overexpressing mice were generated and the browning program of white adipose tissues was induced by both chronic cold stimulation and CL316,243 injection. Body weight, fat mass, lean mass, and energy expenditure were measured, while morphological changes and the expression of thermogenesis-related genes in adipose tissue were analyzed. Moreover, the browning capacity of primary preadipocytes derived from h-overexpressing mice was assessed. RNA sequencing was also employed to investigate the effect of h on the expression of thermogenesis-related genes.
RESULTS
h overexpression in embryonic brown/beige adipose tissues ( ;Cre) led to increased energy expenditure, decreased fat mass, and a lean body phenotype. After acute cold exposure or CL316,243 stimulation, brown/beige tissue h-overexpressing mice showed an increase in expression. Consistent with this, induced h overexpression in adult mice ( ;Cre) also promoted a moderate increase in expression. experiments further revealed that h overexpression induced by -driven Cre recombinase activity upregulated brown/beige adipocytes expression and oxygen consumption rate (OCR). RNA sequencing analyses indicated that h overexpression in brown adipocytes enhanced brown fat cell differentiation, glycolysis, and gluconeogenesis.
CONCLUSION
Consistent with the findings, brown/beige adipocyte-specific overexpression of h promoted expression and thermogenesis, while reducing fat mass.
Topics: Adipose Tissue, Brown; Adipose Tissue, White; Animals; Cell Differentiation; Crosses, Genetic; Genes, Dominant; Homeodomain Proteins; Humans; Hypothalamus; Mice; Phenotype; Polymorphism, Genetic; Thermogenesis; Transcription Factors; Uncoupling Protein 1
PubMed: 33776928
DOI: 10.3389/fendo.2021.634191 -
Scientific Reports Mar 2021The overexpression of hoxd13a during zebrafish fin development causes distal endochondral expansion and simultaneous reduction of the finfold, mimicking the major events...
The overexpression of hoxd13a during zebrafish fin development causes distal endochondral expansion and simultaneous reduction of the finfold, mimicking the major events thought to have happened during the fin-to-limb transition in Vertebrates. We investigated the effect of hoxd13a overexpression on putative downstream targets and found it to cause downregulation of proximal fin identity markers (meis1 and emx2) and upregulation of genes involved in skeletogenesis/patterning (fbn1, dacha) and AER/Finfold maintenance (bmps). We then show that bmp2b overexpression leads to finfold reduction, recapitulating the phenotype observed in hoxd13a-overexpressing fins. In addition, we show that during the development of the long finfold in leo/lof mutants, hoxd13a and bmp2b are downregulated. Our results suggest that modulation of the transcription factor Hoxd13 during evolution may have been involved in finfold reduction through regulation of the Bmp signalling that then activated apoptotic mechanisms impairing finfold elongation.
Topics: Animal Fins; Animals; Animals, Genetically Modified; Apoptosis; Body Patterning; Bone Morphogenetic Protein 2; Down-Regulation; Embryo, Nonmammalian; Gene Expression Regulation, Developmental; Homeodomain Proteins; Models, Animal; Models, Biological; Mutation; Signal Transduction; Skeleton; Transcription Factors; Up-Regulation; Zebrafish; Zebrafish Proteins
PubMed: 33785799
DOI: 10.1038/s41598-021-86621-4 -
Molecular Biology of the Cell Oct 2023Myosin-1s are monomeric actin-based motors that function at membranes. Myo1 is the single myosin-1 isoform in that works redundantly with Wsp1-Vrp1 to activate the...
Myosin-1s are monomeric actin-based motors that function at membranes. Myo1 is the single myosin-1 isoform in that works redundantly with Wsp1-Vrp1 to activate the Arp2/3 complex for endocytosis. Here, we identified Ank1 as an uncharacterized cytoplasmic Myo1 binding partner. We found that in cells, Myo1 dramatically redistributed from endocytic patches to decorate the entire plasma membrane and endocytosis was defective. Biochemical analysis and structural predictions suggested that the Ank1 ankyrin repeats bind the Myo1 lever arm and the Ank1 acidic tail binds the Myo1 TH1 domain to prevent TH1-dependent Myo1 membrane binding. Indeed, Ank1 overexpression precluded Myo1 membrane localization and recombinant Ank1 reduced purified Myo1 liposome binding in vitro. Based on biochemical and cell biological analyses, we propose budding yeast Ank1 and human OSTF1 are functional Ank1 orthologs and that cytoplasmic sequestration by small ankyrin repeat proteins is a conserved mechanism regulating myosin-1s in endocytosis.
Topics: Humans; Schizosaccharomyces pombe Proteins; Ankyrin Repeat; Schizosaccharomyces; Myosins; Actins; Cytoskeletal Proteins; Microfilament Proteins
PubMed: 37531259
DOI: 10.1091/mbc.E23-06-0233 -
PLoS Biology Jul 20231p32.3 microdeletion/duplication is implicated in many neurodevelopmental disorders-like phenotypes such as developmental delay, intellectual disability, autism,...
1p32.3 microdeletion/duplication is implicated in many neurodevelopmental disorders-like phenotypes such as developmental delay, intellectual disability, autism, macro/microcephaly, and dysmorphic features. The 1p32.3 chromosomal region harbors several genes critical for development; however, their validation and characterization remain inadequate. One such gene is the single-stranded DNA-binding protein 3 (SSBP3) and its Drosophila melanogaster ortholog is called sequence-specific single-stranded DNA-binding protein (Ssdp). Here, we investigated consequences of Ssdp manipulations on neurodevelopment, gene expression, physiological function, and autism-associated behaviors using Drosophila models. We found that SSBP3 and Ssdp are expressed in excitatory neurons in the brain. Ssdp overexpression caused morphological alterations in Drosophila wing, mechanosensory bristles, and head. Ssdp manipulations also affected the neuropil brain volume and glial cell number in larvae and adult flies. Moreover, Ssdp overexpression led to differential changes in synaptic density in specific brain regions. We observed decreased levels of armadillo in the heads of Ssdp overexpressing flies, as well as a decrease in armadillo and wingless expression in the larval wing discs, implicating the involvement of the canonical Wnt signaling pathway in Ssdp functionality. RNA sequencing revealed perturbation of oxidative stress-related pathways in heads of Ssdp overexpressing flies. Furthermore, Ssdp overexpressing brains showed enhanced reactive oxygen species (ROS), altered neuronal mitochondrial morphology, and up-regulated fission and fusion genes. Flies with elevated levels of Ssdp exhibited heightened anxiety-like behavior, altered decisiveness, defective sensory perception and habituation, abnormal social interaction, and feeding defects, which were phenocopied in the pan-neuronal Ssdp knockdown flies, suggesting that Ssdp is dosage sensitive. Partial rescue of behavioral defects was observed upon normalization of Ssdp levels. Notably, Ssdp knockdown exclusively in adult flies did not produce behavioral and functional defects. Finally, we show that optogenetic manipulation of Ssdp-expressing neurons altered autism-associated behaviors. Collectively, our findings provide evidence that Ssdp, a dosage-sensitive gene in the 1p32.3 chromosomal region, is associated with various anatomical, physiological, and behavioral defects, which may be relevant to neurodevelopmental disorders like autism. Our study proposes SSBP3 as a critical gene in the 1p32.3 microdeletion/duplication genomic region and sheds light on the functional role of Ssdp in neurodevelopmental processes in Drosophila.
Topics: Animals; Humans; Armadillos; Autistic Disorder; DNA-Binding Proteins; Drosophila; Drosophila melanogaster; Drosophila Proteins; Transcription Factors
PubMed: 37486945
DOI: 10.1371/journal.pbio.3002210 -
Arteriosclerosis, Thrombosis, and... Oct 2023High levels of Lp(a) (lipoprotein(a)) are associated with multiple forms of cardiovascular disease. Lp(a) consists of an apoB-containing particle attached to the...
BACKGROUND
High levels of Lp(a) (lipoprotein(a)) are associated with multiple forms of cardiovascular disease. Lp(a) consists of an apoB-containing particle attached to the plasminogen homologue apo(a). The pathways for Lp(a) clearance are not well understood. We previously discovered that the plasminogen receptor PlgRKT (plasminogen receptor with a C-terminal lysine) promoted Lp(a) uptake in liver cells. Here, we aimed to further define the role of PlgRKT and to investigate the role of 2 other plasminogen receptors, annexin A2 and S100A10 (S100 calcium-binding protein A10) in the endocytosis of Lp(a).
METHODS
Human hepatocellular carcinoma (HepG2) cells and haploid human fibroblast-like (HAP1) cells were used for overexpression and knockout of plasminogen receptors. The uptake of Lp(a), LDL (low-density lipoprotein), apo(a), and endocytic cargos was visualized and quantified by confocal microscopy and Western blotting.
RESULTS
The uptake of both Lp(a) and apo(a), but not LDL, was significantly increased in HepG2 and HAP1 cells overexpressing PlgRKT, annexin A2, or S100A10. Conversely, Lp(a) and apo(a), but not LDL, uptake was significantly reduced in HAP1 cells in which PlgRKT and S100A10 were knocked out. Surface binding studies in HepG2 cells showed that overexpression of PlgRKT, but not annexin A2 or S100A10, increased Lp(a) and apo(a) plasma membrane binding. Annexin A2 and S100A10, on the other hand, appeared to regulate macropinocytosis with both proteins significantly increasing the uptake of the macropinocytosis marker dextran when overexpressed in HepG2 and HAP1 cells and knockout of S100A10 significantly reducing dextran uptake. Bringing these observations together, we tested the effect of a PI3K (phosphoinositide-3-kinase) inhibitor, known to inhibit macropinocytosis, on Lp(a) uptake. Results showed a concentration-dependent reduction confirming that Lp(a) uptake was indeed mediated by macropinocytosis.
CONCLUSIONS
These findings uncover a novel pathway for Lp(a) endocytosis involving multiple plasminogen receptors that enhance surface binding and stimulate macropinocytosis of Lp(a). Although the findings were produced in cell culture models that have limitations, they could have clinical relevance since drugs that inhibit macropinocytosis are in clinical use, that is, the PI3K inhibitors for cancer therapy and some antidepressant compounds.
Topics: Humans; Plasminogen; Lipoprotein(a); Annexin A2; Dextrans; Phosphatidylinositol 3-Kinases; Carrier Proteins; Apolipoproteins A
PubMed: 37589135
DOI: 10.1161/ATVBAHA.123.319344 -
Cell Death & Disease Feb 2022Isoform-specific functions of Numb in the development of cancers, especially in the initiation of epithelial-to-mesenchymal transition (EMT) remains controversial. We...
Isoform-specific functions of Numb in the development of cancers, especially in the initiation of epithelial-to-mesenchymal transition (EMT) remains controversial. We study the specific function of Numb-PRRL isoform in activated EMT of pancreatic ductal adenocarcinoma (PC), which is distinguished from our previous studies that only focused on the total Numb protein. Numb-PRRL isoform was specifically overexpressed and silenced in PC cells combining with TGF-β1 and EGF stimulus. We systematically explored the potential effect of Numb-PRRL in the activated EMT of PC in vitro and in vivo. The total Numb protein was overexpressed in the normal pancreatic duct and well-differentiated PC by IHC. However, Numb-PRRS isoform but not Numb-PRRL showed dominant expression in PC tissues. Numb-PRRL overexpression promoted TGF-β1-induced EMT in PANC-1 and Miapaca-2 cells. TGF-β1-induced EMT-like cell morphology, cell invasion, and migration were enhanced in Numb-PRRL overexpressing groups following the increase of N-cadherin, Vimentin, Smad2/3, Snail1, Snail2, and cleaved-Notch1 and the decrease of E-cadherin. Numb-PRRL overexpression activated TGFβ1-Smad2/3-Snail1 signaling was significantly reversed by the Notch1 inhibitor RO4929097. Conversely, Numb-PRRL silencing inhibited EGF-induced EMT in AsPC-1 and BxPC-3 cells following the activation of EGFR-ERK/MAPK signaling via phosphorylating EGFR at tyrosine 1045. In vivo, Numb-PRRL overexpression or silencing promoted or inhibited subcutaneous tumor size and distant liver metastases via regulating EMT and Snail signaling, respectively. Numb-PRRL promotes TGF-β1- and EGF-induced EMT in PC by regulating TGF-β1-Smad2/3-Snail and EGF-induced EGFR-ERK/MAPK signaling.
Topics: Cell Line, Tumor; Cell Movement; Epidermal Growth Factor; Epithelial-Mesenchymal Transition; ErbB Receptors; Humans; Membrane Proteins; Nerve Tissue Proteins; Pancreatic Neoplasms; Transforming Growth Factor beta1
PubMed: 35197444
DOI: 10.1038/s41419-022-04609-y -
The Plant Journal : For Cell and... Nov 2021Plants resist infection through an innate immune response, which is usually associated with slowing of growth. The molecular mechanisms underlying the trade-off between...
Plants resist infection through an innate immune response, which is usually associated with slowing of growth. The molecular mechanisms underlying the trade-off between plant growth and defense remain unclear. The present study reveals that growth/defense trade-offs mediated by gibberellin (GA) and salicylic acid (SA) signaling pathways are uncoupled during constitutive overexpression of transgenic AtRAN1 and AtRAN1 (active, GTP-locked form) Arabidopsis plants. It is well known that the small GTP-binding protein Ran (a Ras-related nuclear protein) functions in the nucleus-cytoplasmic transport of proteins. Although there is considerable evidence indicating that nuclear-cytoplasmic partitioning of specific proteins can participate in hormone signaling, the role of Ran-dependent nuclear transport in hormone signaling is not yet fully understood. In this report, we used a combination of genetic and molecular methods to reveal whether AtRAN1 is involved in both GA and SA signaling pathways. Constitutively overexpressed AtRAN1 promoted both elongation growth and the disease resistance response, whereas overexpression of AtRAN1 in the atran2atran3 double mutant background clearly inhibited elongation growth and the defense response. Furthermore, we found that AtRAN1 coordinated plant growth and defense by promoting the stability of the DELLA protein RGA in the nucleus and by modulating NPR1 nuclear localization. Interestingly, genetically modified rice (Oryza sativa) overexpressing AtRAN1 exhibited increased plant height and yield per plant. Altogether, the ability to achieve growth/defense trade-offs through AtRAN1 overexpression provides an approach to maximizing crop yield to meet rising global food demands.
Topics: Amino Acid Substitution; Arabidopsis; Arabidopsis Proteins; Cell Nucleus; Cytoplasm; Disease Resistance; Gene Expression; Gibberellins; Mutation; Oryza; Plant Diseases; Plant Growth Regulators; Plants, Genetically Modified; Pseudomonas syringae; RNA-Binding Proteins; Repressor Proteins; Salicylic Acid; Signal Transduction; ran GTP-Binding Protein
PubMed: 34312926
DOI: 10.1111/tpj.15445