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New Mutations in the 5′ Region of the Notch Gene Affect Drosophila melanogaster Oogenesis. J Dev Biol 2022; 10:jdb10030032. [PMID: 35997396 PMCID: PMC9397085 DOI: 10.3390/jdb10030032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 08/01/2022] [Accepted: 08/05/2022] [Indexed: 11/23/2022] Open
Abstract
The Notch pathway is an important and evolutionarily conserved signaling system involved in the development of multicellular organisms. Notch signaling plays an important role in the regulation of proliferation and differentiation of many cell types. In this study, we report new aspects of Notch gene participation in oogenesis using our previously generated mutations. The mutations consist of an insertion of an auxiliary element of a transgene construct into the first intron of the gene and a series of directed deletions within the 5′ regulatory region of Notch. We showed that some of these mutations affect Drosophila oogenesis. This insertion, either alone or in combination with the deletion of an insulator sequence, led to lower expression of Notch in the ovaries. As a result, the formation of egg chambers was disturbed in middle oogenesis. These abnormalities have not been described previously and imply one more function of Notch in oogenesis. It can be assumed that Notch is associated with not only follicular epithelium morphogenesis but also cellular mechanisms of oocyte growth.
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Lata S, Mishra R, Arya RP, Arora P, Lahon A, Banerjea AC, Sood V. Where all the Roads Meet? A Crossover Perspective on Host Factors Regulating SARS-CoV-2 infection. J Mol Biol 2022; 434:167403. [PMID: 34914966 PMCID: PMC8666384 DOI: 10.1016/j.jmb.2021.167403] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 11/18/2021] [Accepted: 12/07/2021] [Indexed: 01/11/2023]
Abstract
COVID-19 caused by SARS-CoV-2 is the latest pandemic which has thrown the world into an unprecedented social and economic uncertainties along with huge loss to humanity. Identification of the host factors regulating the replication of SARS-CoV-2 in human host may help in the development of novel anti-viral therapies to combat the viral infection and spread. Recently, some research groups used genome-wide CRISPR/Cas screening to identify the host factors critical for the SARS-CoV-2 replication and infection. A comparative analysis of these significant host factors (p < 0.05) identified fifteen proteins common in these studies. Apart from ACE2 (receptor for SARS-CoV-2 attachment), other common host factors were CSNK2B, GDI2, SLC35B2, DDX51, VPS26A, ARPP-19, C1QTNF7, ALG6, LIMA1, COG3, COG8, BCOR, LRRN2 and TLR9. Additionally, viral interactome of these host factors revealed that many of them were associated with several SARS-CoV-2 proteins as well. Interestingly, some of these host factors have already been shown to be critical for the pathogenesis of other viruses suggesting their crucial role in virus-host interactions. Here, we review the functions of these host factors and their role in other diseases with special emphasis on viral diseases.
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Affiliation(s)
- Sneh Lata
- Virology Laboratory, National Institute of Immunology, New Delhi, India
| | - Ritu Mishra
- Virology Laboratory, National Institute of Immunology, New Delhi, India
| | - Ravi P. Arya
- KSBS, Indian Institute of Technology, New Delhi, India
| | - Pooja Arora
- Hansraj College, University of Delhi, New Delhi, India
| | | | - Akhil C. Banerjea
- Institute of Advanced Virology, Kerala, India,Corresponding authors
| | - Vikas Sood
- Biochemistry Department, Jamia Hamdard, New Delhi, India,Corresponding authors
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Pokrywka NJ, Bush S, Nick SE. The R-SNARE Ykt6 is required for multiple events during oogenesis in Drosophila. Cells Dev 2021; 169:203759. [PMID: 34856414 DOI: 10.1016/j.cdev.2021.203759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 10/31/2021] [Accepted: 11/21/2021] [Indexed: 11/30/2022]
Abstract
Ykt6 has emerged as a key protein involved in a wide array of trafficking events, and has also been implicated in a number of human pathologies, including the progression of several cancers. It is a complex protein that simultaneously exhibits a high degree of structural and functional homology, and yet adopts differing roles in different cellular contexts. Because Ykt6 has been implicated in a variety of vesicle fusion events, we characterized the role of Ykt6 in oogenesis by observing the phenotype of Ykt6 germline clones. Immunofluorescence was used to visualize the expression of membrane proteins, organelles, and vesicular trafficking markers in mutant egg chambers. We find that Ykt6 germline clones have morphological and actin defects affecting both the nurse cells and oocyte, consistent with a role in regulating membrane growth during mid-oogenesis. Additionally, these egg chambers exhibit defects in bicoid and oskar RNA localization, and in the trafficking of Gurken during mid-to-late oogenesis. Finally, we show that Ykt6 mutations result in defects in late endosomal pathways, including endo- and exocytosis. These findings suggest a role for Ykt6 in endosome maturation and in the movement of membranes to and from the cell surface.
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Affiliation(s)
- Nancy Jo Pokrywka
- Department of Biology, Vassar College, Poughkeepsie, NY 12604, United States of America.
| | - Setse Bush
- Department of Biology, Vassar College, Poughkeepsie, NY 12604, United States of America
| | - Sophie E Nick
- Department of Biology, Vassar College, Poughkeepsie, NY 12604, United States of America
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Singh R, Smit RB, Wang X, Wang C, Racher H, Hansen D. Reduction of Derlin activity suppresses Notch-dependent tumours in the C. elegans germ line. PLoS Genet 2021; 17:e1009687. [PMID: 34555015 PMCID: PMC8491880 DOI: 10.1371/journal.pgen.1009687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 10/05/2021] [Accepted: 09/08/2021] [Indexed: 11/19/2022] Open
Abstract
Regulating the balance between self-renewal (proliferation) and differentiation is key to the long-term functioning of all stem cell pools. In the Caenorhabditis elegans germline, the primary signal controlling this balance is the conserved Notch signaling pathway. Gain-of-function mutations in the GLP-1/Notch receptor cause increased stem cell self-renewal, resulting in a tumour of proliferating germline stem cells. Notch gain-of-function mutations activate the receptor, even in the presence of little or no ligand, and have been associated with many human diseases, including cancers. We demonstrate that reduction in CUP-2 and DER-2 function, which are Derlin family proteins that function in endoplasmic reticulum-associated degradation (ERAD), suppresses the C. elegans germline over-proliferation phenotype associated with glp-1(gain-of-function) mutations. We further demonstrate that their reduction does not suppress other mutations that cause over-proliferation, suggesting that over-proliferation suppression due to loss of Derlin activity is specific to glp-1/Notch (gain-of-function) mutations. Reduction of CUP-2 Derlin activity reduces the expression of a read-out of GLP-1/Notch signaling, suggesting that the suppression of over-proliferation in Derlin loss-of-function mutants is due to a reduction in the activity of the mutated GLP-1/Notch(GF) receptor. Over-proliferation suppression in cup-2 mutants is only seen when the Unfolded Protein Response (UPR) is functioning properly, suggesting that the suppression, and reduction in GLP-1/Notch signaling levels, observed in Derlin mutants may be the result of activation of the UPR. Chemically inducing ER stress also suppress glp-1(gf) over-proliferation but not other mutations that cause over-proliferation. Therefore, ER stress and activation of the UPR may help correct for increased GLP-1/Notch signaling levels, and associated over-proliferation, in the C. elegans germline. Notch signaling is a highly conserved signaling pathway that is utilized in many cell fate decisions in many organisms. In the C. elegans germline, Notch signaling is the primary signal that regulates the balance between stem cell proliferation and differentiation. Notch gain-of-function mutations cause the receptor to be active, even when a signal that is normally needed to activate the receptor is absent. In the germline of C. elegans, gain-of-function mutations in GLP-1, a Notch receptor, results in over-proliferation of the stem cells and tumour formation. Here we demonstrate that a reduction or loss of Derlin activity, which is a conserved family of proteins involved in endoplasmic reticulum-associated degradation (ERAD), suppresses over-proliferation due to GLP-1/Notch gain-of-function mutations. Furthermore, we demonstrate that a surveillance mechanism utilized in cells to monitor and react to proteins that are not folded properly (Unfolded Protein Response-UPR) must be functioning well in order for the loss of Derlin activity to supress over-proliferation caused by glp-1/Notch gain-of-function mutations. This suggests that activation of the UPR may be the mechanism at work for suppressing this type of over-proliferation, when Derlin activity is reduced. Therefore, decreasing Derlin activity may be a means of reducing the impact of phenotypes and diseases due to certain Notch gain-of-function mutations.
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Affiliation(s)
- Ramya Singh
- Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - Ryan B. Smit
- Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - Xin Wang
- Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - Chris Wang
- Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - Hilary Racher
- Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - Dave Hansen
- Department of Biological Sciences, University of Calgary, Calgary, Canada
- * E-mail:
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Gerdes JA, Mannix KM, Hudson AM, Cooley L. HtsRC-Mediated Accumulation of F-Actin Regulates Ring Canal Size During Drosophila melanogaster Oogenesis. Genetics 2020; 216:717-734. [PMID: 32883702 PMCID: PMC7648574 DOI: 10.1534/genetics.120.303629] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 08/30/2020] [Indexed: 12/21/2022] Open
Abstract
Ring canals in the female germline of Drosophila melanogaster are supported by a robust filamentous actin (F-actin) cytoskeleton, setting them apart from ring canals in other species and tissues. Previous work has identified components required for the expansion of the ring canal actin cytoskeleton, but has not identified the proteins responsible for F-actin recruitment or accumulation. Using a combination of CRISPR-Cas9 mediated mutagenesis and UAS-Gal4 overexpression, we show that HtsRC-a component specific to female germline ring canals-is both necessary and sufficient to drive F-actin accumulation. Absence of HtsRC in the germline resulted in ring canals lacking inner rim F-actin, while overexpression of HtsRC led to larger ring canals. HtsRC functions in combination with Filamin to recruit F-actin to ectopic actin structures in somatic follicle cells. Finally, we present findings that indicate that HtsRC expression and robust female germline ring canal expansion are important for high fecundity in fruit flies but dispensable for their fertility-a result that is consistent with our understanding of HtsRC as a newly evolved gene specific to female germline ring canals.
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Affiliation(s)
- Julianne A Gerdes
- Department of Genetics, Yale University School of Medicine, New Haven, 06520 Connecticut
| | - Katelynn M Mannix
- Department of Genetics, Yale University School of Medicine, New Haven, 06520 Connecticut
| | - Andrew M Hudson
- Department of Genetics, Yale University School of Medicine, New Haven, 06520 Connecticut
| | - Lynn Cooley
- Department of Genetics, Yale University School of Medicine, New Haven, 06520 Connecticut
- Department of Cell Biology, Yale University School of Medicine, New Haven, 06520 Connecticut
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511 Connecticut
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Ye H, Ojelade SA, Li-Kroeger D, Zuo Z, Wang L, Li Y, Gu JYJ, Tepass U, Rodal AA, Bellen HJ, Shulman JM. Retromer subunit, VPS29, regulates synaptic transmission and is required for endolysosomal function in the aging brain. eLife 2020; 9:e51977. [PMID: 32286230 PMCID: PMC7182434 DOI: 10.7554/elife.51977] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Accepted: 04/11/2020] [Indexed: 12/13/2022] Open
Abstract
Retromer, including Vps35, Vps26, and Vps29, is a protein complex responsible for recycling proteins within the endolysosomal pathway. Although implicated in both Parkinson's and Alzheimer's disease, our understanding of retromer function in the adult brain remains limited, in part because Vps35 and Vps26 are essential for development. In Drosophila, we find that Vps29 is dispensable for embryogenesis but required for retromer function in aging adults, including for synaptic transmission, survival, and locomotion. Unexpectedly, in Vps29 mutants, Vps35 and Vps26 proteins are normally expressed and associated, but retromer is mislocalized from neuropil to soma with the Rab7 GTPase. Further, Vps29 phenotypes are suppressed by reducing Rab7 or overexpressing the GTPase activating protein, TBC1D5. With aging, retromer insufficiency triggers progressive endolysosomal dysfunction, with ultrastructural evidence of impaired substrate clearance and lysosomal stress. Our results reveal the role of Vps29 in retromer localization and function, highlighting requirements for brain homeostasis in aging.
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Affiliation(s)
- Hui Ye
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
- Department of Neurology, Baylor College of MedicineHoustonUnited States
| | | | - David Li-Kroeger
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Zhongyuan Zuo
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
| | - Liping Wang
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
| | - Yarong Li
- Department of Neurology, Baylor College of MedicineHoustonUnited States
| | - Jessica YJ Gu
- Department of Cell and Systems Biology, University of TorontoOntarioCanada
| | - Ulrich Tepass
- Department of Cell and Systems Biology, University of TorontoOntarioCanada
| | | | - Hugo J Bellen
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Howard Hughes Medical InstituteHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s HospitalHoustonUnited States
| | - Joshua M Shulman
- Department of Molecular and Human Genetics, Baylor College of MedicineHoustonUnited States
- Department of Neurology, Baylor College of MedicineHoustonUnited States
- Program in Developmental Biology, Baylor College of MedicineHoustonUnited States
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s HospitalHoustonUnited States
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Knapp EM, Li W, Sun J. Downregulation of homeodomain protein Cut is essential for Drosophila follicle maturation and ovulation. Development 2019; 146:dev179002. [PMID: 31444217 PMCID: PMC6765176 DOI: 10.1242/dev.179002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 08/19/2019] [Indexed: 01/19/2023]
Abstract
Proper development and maturation of a follicle is essential for successful ovulation and reproduction; however, the molecular mechanisms for follicle maturation, particularly for somatic follicle cell differentiation, are poorly understood. During Drosophila oogenesis, the somatic follicle cells encasing oocytes undergo two distinct well-established transitions: the mitotic to endocycle switch at stage 6/7 and the endocycle to gene amplification switch at stage10A/10B. Here, we identify a novel third follicle cell transition that occurs in the final stages of oogenesis (stage 13/14). This late follicle cell transition is characterized by upregulation of the transcription factor Hindsight (Hnt), and downregulation of the homeodomain transcription factor Cut and the zinc-finger transcription factor Tramtrack-69 (Ttk69). We demonstrate that inducing expression of Cut in stage 14 follicle cells is sufficient to inhibit follicle rupture and ovulation through its negative regulation of Hnt and promotion of Ttk69 expression. Our work illustrates the importance of the stage13/14 transition for follicle maturation and demonstrates the complex regulation required for somatic follicle cells to differentiate into a state primed for follicle rupture and ovulation.
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Affiliation(s)
- Elizabeth M Knapp
- Department of Physiology & Neurobiology, University of Connecticut, Storrs, CT 06269, USA
| | - Wei Li
- Department of Physiology & Neurobiology, University of Connecticut, Storrs, CT 06269, USA
| | - Jianjun Sun
- Department of Physiology & Neurobiology, University of Connecticut, Storrs, CT 06269, USA
- Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269, USA
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Li B, Wong C, Gao SM, Zhang R, Sun R, Li Y, Song Y. The retromer complex safeguards against neural progenitor-derived tumorigenesis by regulating Notch receptor trafficking. eLife 2018; 7:38181. [PMID: 30176986 PMCID: PMC6140715 DOI: 10.7554/elife.38181] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 08/17/2018] [Indexed: 12/14/2022] Open
Abstract
The correct establishment and maintenance of unidirectional Notch signaling are critical for the homeostasis of various stem cell lineages. However, the molecular mechanisms that prevent cell-autonomous ectopic Notch signaling activation and deleterious cell fate decisions remain unclear. Here we show that the retromer complex directly and specifically regulates Notch receptor retrograde trafficking in Drosophila neuroblast lineages to ensure the unidirectional Notch signaling from neural progenitors to neuroblasts. Notch polyubiquitination mediated by E3 ubiquitin ligase Itch/Su(dx) is inherently inefficient within neural progenitors, relying on retromer-mediated trafficking to avoid aberrant endosomal accumulation of Notch and cell-autonomous signaling activation. Upon retromer dysfunction, hypo-ubiquitinated Notch accumulates in Rab7+ enlarged endosomes, where it is ectopically processed and activated in a ligand-dependent manner, causing progenitor-originated tumorigenesis. Our results therefore unveil a safeguard mechanism whereby retromer retrieves potentially harmful Notch receptors in a timely manner to prevent aberrant Notch activation-induced neural progenitor dedifferentiation and brain tumor formation. Most cells in the animal body are tailored to perform particular tasks, but stem cells have not yet made their choice. Instead, they have unlimited capacity to divide and, with the right signals, they can start to specialize to become a given type of cells. In the brain, this process starts with a stem cell dividing. One of the daughters will remain a stem cell, while the other, the neural progenitor, will differentiate to form a mature cell such as a neuron. Keeping this tight balance is crucial for the health of the organ: if the progenitor reverts back to being a stem cell, there will be a surplus of undifferentiated cells that can lead to a tumor. A one-way signal driven by the protein Notch partly controls the distinct fates of the two daughter cells. While the neural progenitor carries Notch at its surface, its neural stem cell sister has a Notch receptor on its membrane instead. This ensures that the Notch signaling goes in one direction, from the cell with Notch to the one sporting the receptor. When a stem cell divides, one daughter gets more of a protein called Numb than the other. Numb pulls Notch receptors away from the external membrane and into internal capsules called endosomes. This guarantees that only one of the siblings will be carrying the receptors at its surface. Yet, sometimes the Notch receptors can get activated in the endosomes, which may make neural progenitors revert to being stem cells. It is still unclear what tools the cells have to stop this abnormal activation. Here, Li et al. screened brain cells from fruit fly larvae to find out the genes that might play a role in suppressing the inappropriate Notch signaling. This highlighted a protein complex known as the retromer, which normally helps to transport proteins in the cell. Experiments showed that, in progenitors, the retromer physically interacts with Notch receptors and retrieves them from the endosomes back to the cell surface. If the retromer is inactive, the Notch receptors accumulate in the endosomes, where they can be switched on. It seems that, in fruit flies, the retromer acts as a bomb squad that recognizes and retrieves potentially harmful Notch receptors, thereby preventing brain tumor formation. Several retromer components are less present in patients with various cancers, including glioblastoma, an aggressive form of brain cancer. The results by Li et al. may therefore shed light on the link between the protein complex and the emergence of the disease in humans.
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Affiliation(s)
- Bo Li
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Peking University, Beijing, China
| | - Chouin Wong
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Peking University, Beijing, China
| | - Shihong Max Gao
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Peking University, Beijing, China
| | - Rulan Zhang
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Peking University, Beijing, China
| | - Rongbo Sun
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing, China.,PKU-IDG/McGovern Institute for Brain Research, Beijing, China
| | - Yulong Li
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing, China.,PKU-IDG/McGovern Institute for Brain Research, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
| | - Yan Song
- Ministry of Education Key Laboratory of Cell Proliferation and Differentiation, School of Life Sciences, Peking University, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, China
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