scholarly journals AGO3 Slicer activity regulates mitochondria–nuage localization of Armitage and piRNA amplification

2014 ◽  
Vol 206 (2) ◽  
pp. 217-230 ◽  
Author(s):  
Haidong Huang ◽  
Yujing Li ◽  
Keith E. Szulwach ◽  
Guoqiang Zhang ◽  
Peng Jin ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Subcellular Localization ◽  
Mitochondrial Fraction ◽  
Rna Cleavage ◽  
Independent Manner ◽  
Ping Pong ◽  
Pirna Pathway

In Drosophila melanogaster the reciprocal “Ping-Pong” cycle of PIWI-interacting RNA (piRNA)–directed RNA cleavage catalyzed by the endonuclease (or “Slicer”) activities of the PIWI proteins Aubergine (Aub) and Argonaute3 (AGO3) has been proposed to expand the secondary piRNA population. However, the role of AGO3/Aub Slicer activity in piRNA amplification remains to be explored. We show that AGO3 Slicer activity is essential for piRNA amplification and that AGO3 inhibits the homotypic Aub:Aub Ping-Pong process in a Slicer-independent manner. We also find that expression of an AGO3 Slicer mutant causes ectopic accumulation of Armitage, a key component in the primary piRNA pathway, in the Drosophila melanogaster germline granules known as nuage. AGO3 also coexists and interacts with Armitage in the mitochondrial fraction. Furthermore, AGO3 acts in conjunction with the mitochondria-associated protein Zucchini to control the dynamic subcellular localization of Armitage between mitochondria and nuage in a Slicer-dependent fashion. Collectively, our findings uncover a new mechanism that couples mitochondria with nuage to regulate secondary piRNA amplification.

scholarly journals Cannabinoids Modulate Food Preference and Consumption in Drosophila Melanogaster

2020 ◽  
Author(s):  
Jianzheng He ◽  
Alice Tan ◽  
Si Ng ◽  
Fengwei Yu
Keyword(s):  
Drosophila Melanogaster ◽  
Food Intake ◽  
Food Preference ◽  
Cannabinoid Receptors ◽  
Fruit Fly ◽  
Inhibitory Effect ◽  
Feeding Behaviors ◽  
Independent Manner ◽  
Inhibit Food Intake

Abstract Cannabinoids have an important role in regulating feeding behaviors via cannabinoid receptors in mammals. Cannabinoids also exhibit potential therapeutic functions in Drosophila melanogaster, or fruit fly that lacks cannabinoid receptors. However, it remains unclear whether cannabinoids affect food consumption and metabolism in a cannabinoid receptors-independent manner in flies. In this study, we systematically investigated pharmacological functions of various cannabinoids in modulating food preference and consumption in flies. We show that flies display preferences for consuming cannabinoids, independent of their sensory functions. Interestingly, phyto- and endo- cannabinoids exhibit an inhibitory effect on food intake. Unexpectedly, the non-selective CB1 receptor antagonist AM251 attenuates the suppression of food intake by endocannabinoids. Moreover, the endocannabinoid anandamide (AEA) and its metabolite inhibit food intake and promote resistance to starvation, possibly through reduced lipid metabolism. Thus, this study has provided insights into a pharmacological role of cannabinoids in feeding behaviors using an adult Drosophila model.

scholarly journals Cannabinoids modulate food preference and consumption in Drosophila melanogaster

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jianzheng He ◽  
Alice Mei Xien Tan ◽  
Si Yun Ng ◽  
Menglong Rui ◽  
Fengwei Yu
Keyword(s):  
Drosophila Melanogaster ◽  
Food Intake ◽  
Food Preference ◽  
Cannabinoid Receptors ◽  
Fruit Fly ◽  
Inhibitory Effect ◽  
Feeding Behaviors ◽  
Independent Manner ◽  
Inhibit Food Intake

AbstractCannabinoids have an important role in regulating feeding behaviors via cannabinoid receptors in mammals. Cannabinoids also exhibit potential therapeutic functions in Drosophila melanogaster, or fruit fly that lacks cannabinoid receptors. However, it remains unclear whether cannabinoids affect food consumption and metabolism in a cannabinoid receptors-independent manner in flies. In this study, we systematically investigated pharmacological functions of various cannabinoids in modulating food preference and consumption in flies. We show that flies display preferences for consuming cannabinoids, independent of two important sensory regulators Poxn and Orco. Interestingly, phyto- and endo- cannabinoids exhibit an inhibitory effect on food intake. Unexpectedly, the non-selective CB1 receptor antagonist AM251 attenuates the suppression of food intake by endocannabinoids. Moreover, the endocannabinoid anandamide (AEA) and its metabolite inhibit food intake and promote resistance to starvation, possibly through reduced lipid metabolism. Thus, this study has provided insights into a pharmacological role of cannabinoids in feeding behaviors using an adult Drosophila model.

scholarly journals Ligand-Independent Antiapoptotic Function of Estrogen Receptor-β in Lung Cancer Cells

2010 ◽  
Vol 24 (9) ◽  
pp. 1737-1747 ◽  
Author(s):  
GuangFeng Zhang ◽  
Naveena Yanamala ◽  
Kira L. Lathrop ◽  
Lin Zhang ◽  
Judith Klein-Seetharaman ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Estrogen Receptor ◽  
Cell Types ◽  
Mitochondrial Fraction ◽  
Apoptotic Pathway ◽  
Independent Manner ◽  
Bh3 Domain ◽  
Exact Function ◽  
Apoptosis Inducing Agents

Abstract Recent studies have demonstrated the presence of estrogen receptor (ER)β in the mitochondria in various cell types and tissues, but the exact function of this localization remains unclear. In this study, we have examined the function of mitochondrial ERβ in non-small-cell lung cancer (NSCLC) cells. Down-regulation of ERβ by short hairpin RNA constructs sensitized NSCLC cells to various apoptosis-inducing agents such as cisplatin, taxol, and etoposide. The increased growth inhibition and induction of apoptosis in ERβ-knockdown cells was observed irrespective of estrogen treatment, suggesting a ligand-independent role of ERβ in regulating the intrinsic apoptotic pathway. Further, ERβ from the mitochondrial fraction physically interacted with the proapoptotic protein Bad, in a ligand-independent manner. Glutathione-S-transferase pull-down assays and molecular modeling studies revealed that the DNA-binding domain and hinge region of ERβ, and the BH3 domain of Bad were involved in these interactions. Further investigations revealed that ERβ inhibited Bad function by disrupting Bad-Bcl-XL and Bad-Bcl-2 interactions. Reintroduction of ERβ in the mitochondria of ERβ knockdown cells reversed their sensitivity to cisplatin. Overall, our results demonstrate a ligand-independent role of ERβ in regulating apoptosis, revealing a novel function for ERβ in the mitochondria.

scholarly journals Cannabinoids modulate food preference and consumption in Drosophila melanogaster

2020 ◽  
Author(s):  
Jianzheng He ◽  
Alice Mei Xien Tan ◽  
Si Yun Ng ◽  
Fengwei Yu
Keyword(s):  
Drosophila Melanogaster ◽  
Food Intake ◽  
Food Preference ◽  
Cannabinoid Receptors ◽  
Fruit Fly ◽  
Inhibitory Effect ◽  
Feeding Behaviors ◽  
Independent Manner ◽  
Inhibit Food Intake

AbstractCannabinoids have an important role in regulating feeding behaviors via cannabinoid receptors in mammals. Cannabinoids also exhibit potential therapeutic functions in Drosophila melanogaster, or fruit fly that lacks cannabinoid receptors. However, it remains unclear whether cannabinoids affect food consumption and metabolism in a cannabinoid receptors-independent manner in flies. In this study, we systematically investigated pharmacological functions of various cannabinoids in modulating food preference and consumption in flies. We show that flies display preferences for consuming cannabinoids, independent of their sensory functions. Interestingly, phyto- and endo- cannabinoids exhibit an inhibitory effect on food intake. Unexpectedly, the non-selective CB1 receptor antagonist AM251 attenuates the suppression of food intake by endocannabinoids. Moreover, the endocannabinoid anandamide (AEA) and its metabolite inhibit food intake and promote resistance to starvation, possibly through reduced lipid metabolism. Thus, this study has provided insights into a pharmacological role of cannabinoids in feeding behaviors using an adult Drosophila model.

scholarly journals Aedes aegypti Piwi4 Structural Features Are Necessary for RNA Binding and Nuclear Localization

2021 ◽  
Vol 22 (23) ◽  
pp. 12733
Author(s):  
Adeline E. Williams ◽  
Gaurav Shrivastava ◽  
Apostolos G. Gittis ◽  
Sundar Ganesan ◽  
Ines Martin-Martin ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Subcellular Localization ◽  
Nuclear Localization ◽  
Rna Binding ◽  
Functional Divergence ◽  
Protein Secondary Structure ◽  
Structural Features ◽  
Site Directed Mutagenesis ◽  
Independent Manner ◽  
Pirna Pathway

The PIWI-interacting RNA (piRNA) pathway provides an RNA interference (RNAi) mechanism known from Drosophila studies to maintain the integrity of the germline genome by silencing transposable elements (TE). Aedes aegypti mosquitoes, which are the key vectors of several arthropod-borne viruses, exhibit an expanded repertoire of Piwi proteins involved in the piRNA pathway, suggesting functional divergence. Here, we investigate RNA-binding dynamics and subcellular localization of A. aegypti Piwi4 (AePiwi4), a Piwi protein involved in antiviral immunity and embryonic development, to better understand its function. We found that AePiwi4 PAZ (Piwi/Argonaute/Zwille), the domain that binds the 3′ ends of piRNAs, bound to mature (3′ 2′ O-methylated) and unmethylated RNAs with similar micromolar affinities (KD = 1.7 ± 0.8 μM and KD of 5.0 ± 2.2 μM, respectively; p = 0.05) in a sequence independent manner. Through site-directed mutagenesis studies, we identified highly conserved residues involved in RNA binding and found that subtle changes in the amino acids flanking the binding pocket across PAZ proteins have significant impacts on binding behaviors, likely by impacting the protein secondary structure. We also analyzed AePiwi4 subcellular localization in mosquito tissues. We found that the protein is both cytoplasmic and nuclear, and we identified an AePiwi4 nuclear localization signal (NLS) in the N-terminal region of the protein. Taken together, these studies provide insights on the dynamic role of AePiwi4 in RNAi and pave the way for future studies aimed at understanding Piwi interactions with diverse RNA populations.

scholarly journals The “Special” crystal-Stellate System in Drosophila melanogaster Reveals Mechanisms Underlying piRNA Pathway-Mediated Canalization

2012 ◽  
Vol 2012 ◽  
pp. 1-5 ◽  
Author(s):  
Maria Pia Bozzetti ◽  
Laura Fanti ◽  
Silvia Di Tommaso ◽  
Lucia Piacentini ◽  
Maria Berloco ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Repetitive Elements ◽  
Genome Integrity ◽  
Molecular Pathways ◽  
Phenotypic Manifestation ◽  
Pirna Pathway ◽  
Shed Light

The Stellate-made crystals formation in spermatocytes is the phenotypic manifestation of a disrupted crystal-Stellate interaction in testes of Drosophila melanogaster. Stellate silencing is achieved by the piRNA pathway, but many features still remain unknown. Here we outline the important role of the crystal-Stellate modifiers. These have shed light on the piRNA pathways that defend genome integrity against transposons and other repetitive elements in the gonads. In particular, we illustrate the finding that HSP90 participates in the molecular pathways of piRNA production. This observation has relevance for the mechanisms underlying the evolutionary canalization process.

scholarly journals piRNAs mediate posttranscriptional retroelement silencing and localization to pi-bodies in the Drosophila germline

2009 ◽  
Vol 186 (3) ◽  
pp. 333-342 ◽  
Author(s):  
Ai Khim Lim ◽  
Liheng Tao ◽  
Toshie Kai
Keyword(s):  
Drosophila Melanogaster ◽  
Messenger Rna ◽  
Mrna Degradation ◽  
Full Length ◽  
Processing Bodies ◽  
Present Evidence ◽  
Maternal Expression ◽  
Germline Cells ◽  
Pirna Pathway

Nuage, a well-conserved perinuclear organelle found in germline cells, is thought to mediate retroelement repression in Drosophila melanogaster by regulating the production of Piwi-interacting RNAs (piRNAs). In this study, we present evidence that the nuage–piRNA pathway components can be found in cytoplasmic foci that also contain retroelement transcripts, antisense piRNAs, and proteins involved in messenger RNA (mRNA) degradation. These mRNA degradation proteins, decapping protein 1/2 (DCP1/2), Me31B (maternal expression at 31B), and pacman (PCM), are normally thought of as components of processing bodies. In spindle-E (spn-E) and aubergine (aub) mutants that lack piRNA production, piRNA pathway proteins no longer overlap the mRNA degradation proteins. Concomitantly, spn-E and aub mutant ovaries show an accumulation of full-length retroelement transcripts and prolonged stabilization of HeT-A mRNA, supporting the role of piRNAs in mediating posttranscriptional retroelement silencing. HeT-A mRNA is derepressed in mRNA degradation mutants twin, dcp1, and ski3, indicating that these enzymes also aid in removing full-length transcripts and/or decay intermediates.

scholarly journals A genetic toolkit for studying transposon control in the Drosophila melanogaster ovary

2021 ◽  
Author(s):  
Julius Brennecke ◽  
Mostafa F ElMaghraby ◽  
Tirian Laszlo ◽  
Kirsten A Senti ◽  
Katharina Meixner
Keyword(s):  
Drosophila Melanogaster ◽  
Cyst Formation ◽  
Resource Center ◽  
Experimental Systems ◽  
Transposon Silencing ◽  
Rna Export ◽  
Nuclear Rna Export ◽  
Pirna Pathway ◽  
Genetic Toolkit

Argonaute proteins of the PIWI class complexed with PIWI-interacting RNAs (piRNAs) protect the animal germline genome by silencing transposable elements. One of the leading experimental systems for studying piRNA biology is the Drosophila melanogaster ovary. In addition to classical mutagenesis, transgenic RNA interference (RNAi), which enables tissue-specific silencing of gene expression, plays a central role in piRNA research. Here, we establish a versatile toolkit focused on piRNA biology that combines germline transgenic RNAi, GFP marker lines for key proteins of the piRNA pathway, and reporter transgenes to establish genetic hierarchies. We compare constitutive, pan-germline RNAi with an equally potent transgenic RNAi system that is activated only after germ cell cyst formation. Stage-specific RNAi allows us to investigate the role of genes essential for germline cell survival, for example nuclear RNA export or the SUMOylation pathway, in piRNA-dependent and independent transposon silencing. Our work forms the basis for an expandable genetic toolkit provided by the Vienna Drosophila Resource Center.

scholarly journals A genetic toolkit for studying transposon control in the Drosophila melanogaster ovary

Genetics ◽  
2021 ◽  
Author(s):  
Mostafa F ElMaghraby ◽  
Laszlo Tirian ◽  
Kirsten-André Senti ◽  
Katharina Meixner ◽  
Julius Brennecke
Keyword(s):  
Drosophila Melanogaster ◽  
Cyst Formation ◽  
Resource Center ◽  
Experimental Systems ◽  
Transposon Silencing ◽  
Rna Export ◽  
Nuclear Rna Export ◽  
Pirna Pathway ◽  
Genetic Toolkit

Abstract Argonaute proteins of the PIWI clade complexed with PIWI-interacting RNAs (piRNAs) protect the animal germline genome by silencing transposable elements. One of the leading experimental systems for studying piRNA biology is the Drosophila melanogaster ovary. In addition to classical mutagenesis, transgenic RNA interference (RNAi), which enables tissue-specific silencing of gene expression, plays a central role in piRNA research. Here, we establish a versatile toolkit focused on piRNA biology that combines germline transgenic RNAi, GFP marker lines for key proteins of the piRNA pathway, and reporter transgenes to establish genetic hierarchies. We compare constitutive, pan-germline RNAi with an equally potent transgenic RNAi system that is activated only after germ cell cyst formation. Stage-specific RNAi allows us to investigate the role of genes essential for germline cell survival, for example nuclear RNA export or the SUMOylation pathway, in piRNA-dependent and independent transposon silencing. Our work forms the basis for an expandable genetic toolkit provided by the Vienna Drosophila Resource Center.

Sign in / Sign up

Export Citation Format

Share Document