scholarly journals Paralogous murine Nudt10 and Nudt11 genes have differential expression patterns but encode identical proteins that are physiologically competent diphosphoinositol polyphosphate phosphohydrolases

2003 ◽  
Vol 373 (1) ◽  
pp. 81-89 ◽  
Author(s):  
Len V. HUA ◽  
Kiyoshi HIDAKA ◽  
Xavier PESESSE ◽  
Larry D. BARNES ◽  
Stephen B. SHEARS

We previously described paralogous human genes {NUDT10 and NUDT11 [where NUDT is (nucleoside diphosphate attached moiety ‘X’)-type motif, also known as the ‘nudix’-type motif]} encoding type 3 diphosphoinositol polyphosphate phosphohydrolases (DIPP3) [Hidaka, Caffrey, Hua, Zhang, Falck, Nickel, Carrel, Barnes and Shears (2002) J. Biol. Chem. 277, 32730–32738]. Normally, gene duplication is redundant, and lacks biological significance. Is this true for the DIPP3 genes? We address this question by characterizing highly-conserved murine Nudt10 and Nudt11 homologues of the human genes. Thus these genes must have been duplicated prior to the divergence of primates and sciurognath rodents, approx. 115 million years ago, greatly exceeding the 4 million year half-life for inactivation of redundant paralogues; our data therefore indicate that the DIPP3 duplication is unusual in being physiologically significant. One possible functional consequence is gene neofunctionalization, but we exclude that, since Nudt10 and Nudt11 encode identical proteins. Another possibility is gene subfunctionalization, which we studied by conducting the first quantitative expression analysis of these genes. We demonstrated high Nudt10 expression in liver, kidney and testis; Nudt11 expression is primarily restricted to the brain. This differential, but complementary, expression pattern indicates that subfunctionalization is the evolutionary consequence of DIPP3 gene duplication. Our kinetic data argue that diphosphoinositol polyphosphates are more physiologically relevant substrates for DIPP3 than are either diadenosine hexaphosphate or 5-phosphoribosyl 1-pyrophosphate. Thus the significance of the Nudt10/Nudt11 duplication is specific hydrolysis of diphosphoinositol polyphosphates in a tissue-dependent manner.


2021 ◽  
Vol 7 (3) ◽  
pp. eabc8873
Author(s):  
Peng Qin ◽  
Guohua Zhang ◽  
Binhua Hu ◽  
Jie Wu ◽  
Weilan Chen ◽  
...  

Long-distance transport of the phytohormone abscisic acid (ABA) has been studied for ~50 years, yet its mechanistic basis and biological significance remain very poorly understood. Here, we show that leaf-derived ABA controls rice seed development in a temperature-dependent manner and is regulated by defective grain-filling 1 (DG1), a multidrug and toxic compound extrusion transporter that effluxes ABA at nodes and rachilla. Specifically, ABA is biosynthesized in both WT and dg1 leaves, but only WT caryopses accumulate leaf-derived ABA. Our demonstration that leaf-derived ABA activates starch synthesis genes explains the incompletely filled and floury seed phenotypes in dg1. Both the DG1-mediated long-distance ABA transport efficiency and grain-filling phenotypes are temperature sensitive. Moreover, we extended these mechanistic insights to other cereals by observing similar grain-filling defects in a maize DG1 ortholog mutant. Our study demonstrates that rice uses a leaf-to-caryopsis ABA transport–based mechanism to ensure normal seed development in response to variable temperatures.



2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1321.1-1321
Author(s):  
S. Nagpal ◽  
S. Cole ◽  
A. Floudas ◽  
M. Wechalekar ◽  
Q. Song ◽  
...  

Background:Immune checkpoint blockade with agents targeting CTLA4 and PD-1/PD-L1 alone or in combination has demonstrated exceptional efficacy in multiple cancer types by “unleashing” the cytotoxic action of quiescent, tumor-infiltrating T cells. However, the therapeutic action of these immunotherapies goes hand in hand with the loss of immune tolerance and appearance of immune-related adverse events such as colitis, arthralgia and inflammatory arthritis in responsive patients. Therefore, immune checkpoint molecules have been proposed as targets for the treatment of autoimmune diseases.Objectives:Herein, we interrogate the potential of BTLA/HVEM axis as a target for restoring immune homeostasis in rheumatoid arthritis (RA), Systemic Lupus Erythematosus (SLE) and Sjogren’s Syndrome (SjS) by examining their expression patterns in autoimmune disease tissues.Methods:Message and protein expression of BTLA and HVEM were examined in RA and SLE synovial tissues, SLE cutaneous lesions, SjS salivary glands and peripheral blood samples of autoimmune disease by RNA sequencing and flow cytometry.Results:Tissue dysregulation of the BTLA-HVEM axis was observed: Increased BTLA RNA level in RA synovium, SLE-affected skin, and SjS salivary gland samples, whereas HVEM level was affected only in the RA synovium when compared to unaffected tissues. Detailed immunophenotyping of B, T, and myeloid cell populations in RA, SLE, SjS and healthy control PBMCs revealed differential modulation of the BTLA+ or HVEM+ immune cell subsets in a disease-context dependent manner. SjS patients showed an overall decrease in memory B cells and most of the BTLA+ B cell subsets while a decrease in HVEM+ B cells was observed only in SLE PBMC samples and not RA and SLE samples. Immunophenotyping with a T cell panel exhibited decreased BTLA and HVEM expression on T cell subsets in SjS and SLE but not in RA patients. In addition, protein levels of HVEM were differentially decreased in SLE myeloid cell subsets. Finally, we demonstrate tissue-specific surface expression patterns of BTLA in RA and SLE samples: higher surface BTLA levels on RA and SLE PBMC B cells than matched tissue-derived B cells.Conclusion:Our results demonstrate a dysregulation of the BTLA/HVEM axis in either lesional tissue or peripheral blood in an autoimmune disease context-dependent manner. These results also indicate the potential of targeting BTLA-HVEM axis for the treatment of multiple autoimmune diseases.Disclosure of Interests:Sunil Nagpal Shareholder of: Janssen Pharmaceuticals, Employee of: Janssen Pharmaceuticals, Suzanne Cole Shareholder of: Janssen Research & Development employee, Employee of: Janssen Research & Development employee, Achilleas Floudas: None declared, Mihir Wechalekar Grant/research support from: Grant from Janssen Research & Development, Qingxuan Song Shareholder of: Employee of Janssen Research, Employee of: Employee of Janssen Research, Tom Gordon: None declared, Roberto Caricchio Grant/research support from: Financial grant from Janssen Research & Development, Douglas Veale: None declared, Ursula Fearon: None declared, Navin Rao Shareholder of: Janssen Pharmaceuticals, Employee of: Janssen Pharmaceuticals, Ling-Yang Hao Shareholder of: Employee of Janssen Research, Employee of: Employee of Janssen Research



2021 ◽  
Vol 12 (1) ◽  
Author(s):  
David S. M. Lee ◽  
Joseph Park ◽  
Andrew Kromer ◽  
Aris Baras ◽  
Daniel J. Rader ◽  
...  

AbstractRibosome-profiling has uncovered pervasive translation in non-canonical open reading frames, however the biological significance of this phenomenon remains unclear. Using genetic variation from 71,702 human genomes, we assess patterns of selection in translated upstream open reading frames (uORFs) in 5’UTRs. We show that uORF variants introducing new stop codons, or strengthening existing stop codons, are under strong negative selection comparable to protein-coding missense variants. Using these variants, we map and validate gene-disease associations in two independent biobanks containing exome sequencing from 10,900 and 32,268 individuals, respectively, and elucidate their impact on protein expression in human cells. Our results suggest translation disrupting mechanisms relating uORF variation to reduced protein expression, and demonstrate that translation at uORFs is genetically constrained in 50% of human genes.



2009 ◽  
Vol 187 (7) ◽  
pp. 1101-1116 ◽  
Author(s):  
Chiara Francavilla ◽  
Paola Cattaneo ◽  
Vladimir Berezin ◽  
Elisabeth Bock ◽  
Diletta Ami ◽  
...  

Neural cell adhesion molecule (NCAM) associates with fibroblast growth factor (FGF) receptor-1 (FGFR1). However, the biological significance of this interaction remains largely elusive. In this study, we show that NCAM induces a specific, FGFR1-mediated cellular response that is remarkably different from that elicited by FGF-2. In contrast to FGF-induced degradation of endocytic FGFR1, NCAM promotes the stabilization of the receptor, which is recycled to the cell surface in a Rab11- and Src-dependent manner. In turn, FGFR1 recycling is required for NCAM-induced sustained activation of various effectors. Furthermore, NCAM, but not FGF-2, promotes cell migration, and this response depends on FGFR1 recycling and sustained Src activation. Our results implicate NCAM as a nonconventional ligand for FGFR1 that exerts a peculiar control on the intracellular trafficking of the receptor, resulting in a specific cellular response. Besides introducing a further level of complexity in the regulation of FGFR1 function, our findings highlight the link of FGFR recycling with sustained signaling and cell migration and the critical role of these events in dictating the cellular response evoked by receptor activation.



1986 ◽  
Vol 240 (3) ◽  
pp. 731-737 ◽  
Author(s):  
M E Dunlop ◽  
R G Larkins

Stimulated hydrolysis of the inositol phospholipids phosphatidylinositol 4-phosphate (PtdIns4P) and phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] was investigated by studying the phosphoinositides produced in a suspended preparation of plasma membranes by transference of 32P from [gamma-32P]ATP. At basal Ca2+ concentration (calculated free Ca2+, 150 nM) phospholipid hydrolysis was stimulated either by the muscarinic agonists carbamoylcholine and bethanecol or by the addition of the non-hydrolysable analogue of GTP, guanosine 5′-[beta gamma-imido]triphosphate [p(NH)ppG]. GTP was without effect on basal hyrolysis. Both GTP and p(NH)ppG enhanced the rapid (within 10 s) hydrolysis of PtdIns4P and PtdIns(4,5)P2 induced by carbamoylcholine in a dose-dependent manner. A rightward shift in the competition curve of carbamoylcholine for bound L-[3H]quinuclidinyl benzilate was seen on addition of GTP or p(NH)ppG (100 microM) under phosphorylating conditions. Pretreatment of intact islet cells with Bordetella pertussis toxin, islet-activating protein (IAP) or treatment of membranes with IAP under conditions which elicited ADP-ribosylation of a protein of Mr 41,000 was without effect on muscarinic binding, phosphoinositide phosphorylation or subsequent hydrolysis by carbamoylcholine. The findings indicate the involvement of a GTP-binding protein in the coupling of the muscarinic receptor to phosphoinositide hydrolysis in the islet cell and suggest that this is distinct from the GTP-binding regulatory component of adenylate cyclase which is covalently modified by IAP.



2002 ◽  
Vol 282 (1) ◽  
pp. H175-H183 ◽  
Author(s):  
Leonard Kleine ◽  
Gele Liu ◽  
Normand Leblanc ◽  
Richard L. Hébert

Bradykinin (BK), a proinflammatory factor and vasodilator, causes functional change of the small artery. However, it is not clear whether any of these changes induced by BK are mediated by N-acetyl-d-sphingosine (ceramide). Therefore, we investigated whether BK affects the hydrolysis of sphingomyelin and generation of ceramide in the intact rat small artery. Our results suggest that BK induces sphingomyelin hydrolysis and increases ceramide production in a time- and dose-dependent manner. Relative to controls, BK causes a 50% decrease in sphingomyelin levels. Ceramide levels increase in response to BK with the highest level being obtained with 10−8M BK as well as similar amounts of ceramide are generated when exogenous sphingomyelinase (SMase) is added. We then determined which of the two BK receptors (BK-B1antagonist Lys-Des-Arg9-Leu8-BK or the BK-B2antagonist HOE-140) are implicated in the BK-induced generation of ceramide. The BK-B2antagonist did not alter the effect of BK on ceramide generation, whereas the BK-B1antagonist blocked the BK-induced production of ceramide. Although ceramide had no effect on KCl-induced constrictions, ceramide dilated preconstricted (phenylephrine) small pressurized rat mesenteric arteries by ∼40%. These results suggest that the activation of the BK-B1receptor mediates the BK-induced activation of SMase and of the production of ceramide. In conclusion, BK-mediated effects on vascular tone may be due, at least in part, to the increased production of ceramide.



2020 ◽  
Vol 18 (06) ◽  
pp. 2050038
Author(s):  
Jorge Parraga-Alava ◽  
Mario Inostroza-Ponta

Using a prior biological knowledge of relationships and genetic functions for gene similarity, from repository such as the Gene Ontology (GO), has shown good results in multi-objective gene clustering algorithms. In this scenario and to obtain useful clustering results, it would be helpful to know which measure of biological similarity between genes should be employed to yield meaningful clusters that have both similar expression patterns (co-expression) and biological homogeneity. In this paper, we studied the influence of the four most used GO-based semantic similarity measures in the performance of a multi-objective gene clustering algorithm. We used four publicly available datasets and carried out comparative studies based on performance metrics for the multi-objective optimization field and clustering performance indexes. In most of the cases, using Jiang–Conrath and Wang similarities stand in terms of multi-objective metrics. In clustering properties, Resnik similarity allows to achieve the best values of compactness and separation and therefore of co-expression of groups of genes. Meanwhile, in biological homogeneity, the Wang similarity reports greater number of significant GO terms. However, statistical, visual, and biological significance tests showed that none of the GO-based semantic similarity measures stand out above the rest in order to significantly improve the performance of the multi-objective gene clustering algorithm.



2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Kristof Y. Neven ◽  
Bianca Cox ◽  
Karen Vrijens ◽  
Michelle Plusquin ◽  
Harry A. Roels ◽  
...  

Abstract Background Iodine is an essential trace element for the production of thyroid hormones, and plays a key role during the gestational period for optimal foetal growth and (neuro-)development. To this day, iodine deficiency remains a global burden. Previous studies indicate that the placenta can store iodine in a concentration-dependent manner and serve as a long-term storage supply, but studies on the determinants of long-term placental iodine load are limited. Methods The placental iodine concentrations were determined for 462 mother-neonate pairs from the ENVIRONAGE birth cohort (Limburg, Belgium). Sociodemographic and clinical variables were obtained from questionnaires and medical files. Determinants of placental iodine concentration were identified using stepwise multiple regression procedures (p value < 0.15). The biological significance of our findings was investigated by measuring the plasma thyroid hormones in maternal and cord blood of 378 participants. Results A higher pre-pregnancy BMI, higher gestational weight gain, and alcohol consumption during pregnancy were linked with lower placental iodine storage. Multi-vitamin supplementation during pregnancy and longer gestation were associated with higher levels of placental iodine. Children born during the winter period had on average higher placental iodine levels. Besides, we found a significant positive time trend for placental iodine load over the study period 2013 to 2017. Lastly, we observed positive associations of both the maternal and cord plasma thyroxine concentrations with placental iodine load, emphasizing their biological link. Conclusions This study identified some determinants likely presenting a risk of reduced iodine storage during the gestational period of life. Future studies should elucidate the effects of lower placental iodine load on neonatal health, and health later in life.



2008 ◽  
Vol 28 (21) ◽  
pp. 6668-6680 ◽  
Author(s):  
Albertus T. J. Wierenga ◽  
Edo Vellenga ◽  
Jan Jacob Schuringa

ABSTRACT The level of transcription factor activity critically regulates cell fate decisions, such as hematopoietic stem cell (HSC) self-renewal and differentiation. We introduced STAT5A transcriptional activity into human HSCs/progenitor cells in a dose-dependent manner by overexpression of a tamoxifen-inducible STAT5A(1*6)-estrogen receptor fusion protein. Induction of STAT5A activity in CD34+ cells resulted in impaired myelopoiesis and induction of erythropoiesis, which was most pronounced at the highest STAT5A transactivation levels. In contrast, intermediate STAT5A activity levels resulted in the most pronounced proliferative advantage of CD34+ cells. This coincided with increased cobblestone area-forming cell and long-term-culture-initiating cell frequencies, which were predominantly elevated at intermediate STAT5A activity levels but not at high STAT5A levels. Self-renewal of progenitors was addressed by serial replating of CFU, and only progenitors containing intermediate STAT5A activity levels contained self-renewal capacity. By extensive gene expression profiling we could identify gene expression patterns of STAT5 target genes that predominantly associated with a self-renewal and long-term expansion phenotype versus those that identified a predominant differentiation phenotype.



2018 ◽  
Vol 19 (10) ◽  
pp. 3072 ◽  
Author(s):  
Andrzej Slominski ◽  
Tae-Kang Kim ◽  
Zorica Janjetovic ◽  
Anna Brożyna ◽  
Michal Żmijewski ◽  
...  

A novel pathway of vitamin D activation by CYP11A has previously been elucidated. To define the mechanism of action of its major dihydroxy-products, we tested the divergence and overlap between the gene expression profiles of human epidermal keratinocytes treated with either CYP11A1-derived 20,23(OH)2D3 or classical 1,25(OH)2D3. Both secosteroids have significant chemical similarity with the only differences being the positions of the hydroxyl groups. mRNA was isolated and examined by microarray analysis using Illumina’s HumanWG-6 chip/arrays and subsequent bioinformatics analyses. Marked differences in the up- and downregulated genes were observed between 1,25(OH)2D3- and 20,23(OH)2D3-treated cells. Hierarchical clustering identified both distinct, opposite and common (overlapping) gene expression patterns. CYP24A1 was a common gene strongly activated by both compounds, a finding confirmed by qPCR. Ingenuity pathway analysis identified VDR/RXR signaling as the top canonical pathway induced by 1,25(OH)2D3. In contrast, the top canonical pathway induced by 20,23(OH)2D3 was AhR, with VDR/RXR being the second nuclear receptor signaling pathway identified. QPCR analyses validated the former finding by revealing that 20,23(OH)2D3 stimulated CYP1A1 and CYP1B1 gene expression, effects located downstream of AhR. Similar stimulation was observed with 20(OH)D3, the precursor to 20,23(OH)2D3, as well as with its downstream metabolite, 17,20,23(OH)3D3. Using a Human AhR Reporter Assay System we showed marked activation of AhR activity by 20,23(OH)2D3, with weaker stimulation by 20(OH)D3. Finally, molecular modeling using an AhR LBD model predicted vitamin D3 hydroxyderivatives to be good ligands for this receptor. Thus, our microarray, qPCR, functional studies and molecular modeling indicate that AhR is the major receptor target for 20,23(OH)2D3, opening an exciting area of investigation on the interaction of different vitamin D3-hydroxyderivatives with AhR and the subsequent downstream activation of signal transduction pathways in a cell-type-dependent manner.



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