1
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Paniagua N, Roberts CJ, Gonzalez LE, Monedero-Alonso D, Reinke V. The Upstream Sequence Transcription Complex dictates nucleosome positioning and promoter accessibility at piRNA genes in the C. elegans germ line. PLoS Genet 2024; 20:e1011345. [PMID: 38985845 DOI: 10.1371/journal.pgen.1011345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Accepted: 06/16/2024] [Indexed: 07/12/2024] Open
Abstract
The piRNA pathway is a conserved germline-specific small RNA pathway that ensures genomic integrity and continued fertility. In C. elegans and other nematodes, Type-I piRNAs are expressed from >10,000 independently transcribed genes clustered within two discrete domains of 1.5 and 3.5 MB on Chromosome IV. Clustering of piRNA genes contributes to their germline-specific expression, but the underlying mechanisms are unclear. We analyze isolated germ nuclei to demonstrate that the piRNA genomic domains are located in a heterochromatin-like environment. USTC (Upstream Sequence Transcription Complex) promotes strong association of nucleosomes throughout piRNA clusters, yet organizes the local nucleosome environment to direct the exposure of individual piRNA genes. Localization of USTC to the piRNA domains depends upon the ATPase chromatin remodeler ISW-1, which maintains high nucleosome density across piRNA clusters and ongoing production of piRNA precursors. Overall, this work provides insight into how chromatin states coordinate transcriptional regulation over large genomic domains, with implications for global genome organization.
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Affiliation(s)
- Nancy Paniagua
- Department of Genetics, Yale University School of Medicine, New Haven Connecticut, United States of America
| | - C Jackson Roberts
- Department of Genetics, Yale University School of Medicine, New Haven Connecticut, United States of America
| | - Lauren E Gonzalez
- Department of Genetics, Yale University School of Medicine, New Haven Connecticut, United States of America
| | - David Monedero-Alonso
- Department of Genetics, Yale University School of Medicine, New Haven Connecticut, United States of America
| | - Valerie Reinke
- Department of Genetics, Yale University School of Medicine, New Haven Connecticut, United States of America
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2
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Meisel JD, Wiesenthal PP, Mootha VK, Ruvkun G. CMTR-1 RNA methyltransferase mutations activate widespread expression of a dopaminergic neuron-specific mitochondrial complex I gene. Curr Biol 2024; 34:2728-2738.e6. [PMID: 38810637 DOI: 10.1016/j.cub.2024.04.079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 03/05/2024] [Accepted: 04/30/2024] [Indexed: 05/31/2024]
Abstract
The mitochondrial proteome is comprised of approximately 1,100 proteins,1 all but 12 of which are encoded by the nuclear genome in C. elegans. The expression of nuclear-encoded mitochondrial proteins varies widely across cell lineages and metabolic states,2,3,4 but the factors that specify these programs are not known. Here, we identify mutations in two nuclear-localized mRNA processing proteins, CMTR1/CMTR-1 and SRRT/ARS2/SRRT-1, which we show act via the same mechanism to rescue the mitochondrial complex I mutant NDUFS2/gas-1(fc21). CMTR-1 is an FtsJ-family RNA methyltransferase that, in mammals, 2'-O-methylates the first nucleotide 3' to the mRNA CAP to promote RNA stability and translation5,6,7,8. The mutations isolated in cmtr-1 are dominant and lie exclusively in the regulatory G-patch domain. SRRT-1 is an RNA binding partner of the nuclear cap-binding complex and determines mRNA transcript fate.9 We show that cmtr-1 and srrt-1 mutations activate embryonic expression of NDUFS2/nduf-2.2, a paralog of NDUFS2/gas-1 normally expressed only in dopaminergic neurons, and that nduf-2.2 is necessary for the complex I rescue by the cmtr-1 G-patch mutant. Additionally, we find that loss of the cmtr-1 G-patch domain cause ectopic localization of CMTR-1 protein to processing bodies (P bodies), phase-separated organelles involved in mRNA storage and decay.10 P-body localization of the G-patch mutant CMTR-1 contributes to the rescue of the hyperoxia sensitivity of the NDUFS2/gas-1 mutant. This study suggests that mRNA methylation at P bodies may control nduf-2.2 gene expression, with broader implications for how the mitochondrial proteome is translationally remodeled in the face of tissue-specific metabolic requirements and stress.
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Affiliation(s)
- Joshua D Meisel
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Presli P Wiesenthal
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Vamsi K Mootha
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA.
| | - Gary Ruvkun
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA.
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3
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Breen PC, Kanakanui KG, Newman MA, Dowen RH. The F-box protein FBXL-5 governs vitellogenesis and lipid homeostasis in C. elegans. Front Cell Dev Biol 2024; 12:1389077. [PMID: 38946799 PMCID: PMC11211535 DOI: 10.3389/fcell.2024.1389077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Accepted: 05/22/2024] [Indexed: 07/02/2024] Open
Abstract
The molecular mechanisms that govern the metabolic commitment to reproduction, which often occurs at the expense of somatic reserves, remain poorly understood. We identified the Caenorhabditis elegans F-box protein FBXL-5 as a negative regulator of maternal provisioning of vitellogenin lipoproteins, which mediate the transfer of intestinal lipids to the germline. Mutations in fbxl-5 partially suppress the vitellogenesis defects observed in the heterochronic mutants lin-4 and lin-29, both of which ectopically express fbxl-5 at the adult developmental stage. FBXL-5 functions in the intestine to negatively regulate expression of the vitellogenin genes; and consistently, intestine-specific over-expression of FBXL-5 is sufficient to inhibit vitellogenesis, restrict lipid accumulation, and shorten lifespan. Our epistasis analyses suggest that fbxl-5 functions in concert with cul-6, a cullin gene, and the Skp1-related gene skr-3 to regulate vitellogenesis. Additionally, fbxl-5 acts genetically upstream of rict-1, which encodes the core mTORC2 protein Rictor, to govern vitellogenesis. Together, our results reveal an unexpected role for a SCF ubiquitin-ligase complex in controlling intestinal lipid homeostasis by engaging mTORC2 signaling.
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Affiliation(s)
- Peter C. Breen
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
| | - Kendall G. Kanakanui
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
| | - Martin A. Newman
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
| | - Robert H. Dowen
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, Unites States
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4
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Singh N, Zhang P, Li KJ, Gordon KL. The Rac pathway prevents cell fragmentation in a nonprotrusively migrating leader cell during C. elegans gonad organogenesis. Curr Biol 2024; 34:2387-2402.e5. [PMID: 38776905 DOI: 10.1016/j.cub.2024.04.073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 03/22/2024] [Accepted: 04/29/2024] [Indexed: 05/25/2024]
Abstract
The C. elegans hermaphrodite distal tip cell (DTC) leads gonadogenesis. Loss-of-function mutations in a C. elegans ortholog of the Rac1 GTPase (ced-10) and its GEF complex (ced-5/DOCK180, ced-2/CrkII, ced-12/ELMO) cause gonad migration defects related to directional sensing; we discovered an additional defect class of gonad bifurcation in these mutants. Using genetic approaches, tissue-specific and whole-body RNAi, and in vivo imaging of endogenously tagged proteins and marked cells, we find that loss of Rac1 or its regulators causes the DTC to fragment as it migrates. Both products of fragmentation-the now-smaller DTC and the membranous patch of cellular material-localize important stem cell niche signaling (LAG-2 ligand) and migration (INA-1/integrin subunit alpha) factors to their membranes, but only one retains the DTC nucleus and therefore the ability to maintain gene expression over time. The enucleate patch can lead a bifurcating branch off the gonad arm that grows through germ cell proliferation. Germ cells in this branch differentiate as the patch loses LAG-2 expression. While the nucleus is surprisingly dispensable for aspects of leader cell function, it is required for stem cell niche activity long term. Prior work found that Rac1-/-;Rac2-/- mouse erythrocytes fragment; in this context, our new findings support the conclusion that maintaining a cohesive but deformable cell is a conserved function of this important cytoskeletal regulator.
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Affiliation(s)
- Noor Singh
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Pu Zhang
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Karen Jian Li
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Kacy Lynn Gordon
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
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5
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Yanagi KS, Lehrbach N. Streamlined single shot safe harbor transgene integration in C. elegans using unc-119 rescue. MICROPUBLICATION BIOLOGY 2024; 2024:10.17912/micropub.biology.001230. [PMID: 38872845 PMCID: PMC11170288 DOI: 10.17912/micropub.biology.001230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 05/23/2024] [Accepted: 05/27/2024] [Indexed: 06/15/2024]
Abstract
Transgenic animals are an invaluable tool in model organism genetics. The ease of modifying the C. elegans genome through high-copy integration of transgenes facilitates the investigation of diverse and fundamental biological processes. However, generation of new multicopy integrated transgenes is limited by the time and labor cost. Further, many transgenes are integrated using non-specific DNA damaging agents. These DNA damaging agents cause unwanted mutations during the integration process and may have deleterious effects. A recently described method for CRISPR/Cas9-based integration of multicopy transgenes at safe harbor loci using Fluorescent Landmark Interference (FLInt) greatly increases the efficiency of multicopy transgene integration and mitigates issues related to off-target mutagenesis during integration. unc-119 rescue is a simple and widely used phenotypic marker in C. elegans transgenesis and genome engineering. To streamline generation of multicopy transgenes via FLInt, we have generated a set of strains suitable for FLInt-mediated integration of transgenes using rescue of the unc-119 mutant phenotype to select transgenic animals. We demonstrate the utility of this approach and outline a protocol that uses unc-119 rescue as a selection marker for streamlined integration of multicopy transgenes at safe harbor loci.
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Affiliation(s)
- Katherine S. Yanagi
- Basic Sciences Division, Fred Hutch Cancer Center, Seattle, Washington, United States
| | - Nicolas Lehrbach
- Basic Sciences Division, Fred Hutch Cancer Center, Seattle, Washington, United States
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6
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Nahar S, Morales Moya LJ, Brunner J, Hendriks GJ, Towbin B, Hauser Y, Brancati G, Gaidatzis D, Großhans H. Dynamics of miRNA accumulation during C. elegans larval development. Nucleic Acids Res 2024; 52:5336-5355. [PMID: 38381904 PMCID: PMC11109986 DOI: 10.1093/nar/gkae115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 02/01/2024] [Accepted: 02/06/2024] [Indexed: 02/23/2024] Open
Abstract
Temporally and spatially controlled accumulation underlies the functions of microRNAs (miRNAs) in various developmental processes. In Caenorhabditis elegans, this is exemplified by the temporal patterning miRNAs lin-4 and let-7, but for most miRNAs, developmental expression patterns remain poorly resolved. Indeed, experimentally observed long half-lives may constrain possible dynamics. Here, we profile miRNA expression throughout C. elegans postembryonic development at high temporal resolution, which identifies dynamically expressed miRNAs. We use mathematical models to explore the underlying mechanisms. For let-7, we can explain, and experimentally confirm, a striking stepwise accumulation pattern through a combination of rhythmic transcription and stage-specific regulation of precursor processing by the RNA-binding protein LIN-28. By contrast, the dynamics of several other miRNAs cannot be explained by regulation of production rates alone. Specifically, we show that a combination of oscillatory transcription and rhythmic decay drive rhythmic accumulation of miR-235, orthologous to miR-92 in other animals. We demonstrate that decay of miR-235 and additional miRNAs depends on EBAX-1, previously implicated in target-directed miRNA degradation (TDMD). Taken together, our results provide insight into dynamic miRNA decay and establish a resource to studying both the developmental functions of, and the regulatory mechanisms acting on, miRNAs.
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Affiliation(s)
- Smita Nahar
- Friedrich Miescher Institute for Biomedical Research (FMI), Basel, Switzerland
| | | | - Jana Brunner
- Friedrich Miescher Institute for Biomedical Research (FMI), Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Gert-Jan Hendriks
- Friedrich Miescher Institute for Biomedical Research (FMI), Basel, Switzerland
| | - Benjamin Towbin
- Friedrich Miescher Institute for Biomedical Research (FMI), Basel, Switzerland
- University of Bern, Bern, Switzerland
| | - Yannick P Hauser
- Friedrich Miescher Institute for Biomedical Research (FMI), Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Giovanna Brancati
- Friedrich Miescher Institute for Biomedical Research (FMI), Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Dimos Gaidatzis
- Friedrich Miescher Institute for Biomedical Research (FMI), Basel, Switzerland
- SIB Swiss Institute of Bioinformatics, Basel, Switzerland
| | - Helge Großhans
- Friedrich Miescher Institute for Biomedical Research (FMI), Basel, Switzerland
- University of Basel, Basel, Switzerland
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7
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Beyrent E, Wei DT, Beacham GM, Park S, Zheng J, Paszek MJ, Hollopeter G. Dimerization activates the Inversin complex in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.17.594761. [PMID: 38798613 PMCID: PMC11118560 DOI: 10.1101/2024.05.17.594761] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Genetic, colocalization, and biochemical studies suggest that the ankyrin repeat-containing proteins Inversin (INVS) and ANKS6 function with the NEK8 kinase to control tissue patterning and maintain organ physiology. It is unknown whether these three proteins assemble into a static "Inversin complex" or one that adopts multiple bioactive forms. Through characterization of hyperactive alleles in C. elegans , we discovered that the Inversin complex is activated by dimerization. Genome engineering of an RFP tag onto the nematode homologs of INVS (MLT-4) and NEK8 (NEKL-2) induced a gain-of-function, cyst-like phenotype that was suppressed by monomerization of the fluorescent tag. Stimulated dimerization of MLT-4 or NEKL-2 using optogenetics was sufficient to recapitulate the phenotype of a constitutively active Inversin complex. Further, dimerization of NEKL-2 bypassed a lethal MLT-4 mutant, demonstrating that the dimeric form is required for function. We propose that dynamic switching between at least two functionally distinct states-an active dimer and an inactive monomer-gates the output of the Inversin complex.
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8
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Ragle JM, Turzo A, Levenson MT, Jonnalagadda K, Jackson A, Vo AA, Pham VT, Ward JD. MLT-11 is a transient apical extracellular matrix component required for cuticle patterning and function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.12.593762. [PMID: 38766248 PMCID: PMC11100798 DOI: 10.1101/2024.05.12.593762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Apical extracellular matrices (aECMs) are associated with all epithelia and form a protective layer against biotic and abiotic threats in the environment. Despite their importance, we lack a deep understanding of their structure and dynamics in development and disease. C. elegans molting offers a powerful entry point to understanding developmentally programmed aECM remodeling. A transient matrix is formed in embryos and at the end of each larval stage, presumably to pattern the new cuticle. Focusing on targets of NHR-23, a key transcription factor which drives molting, we identified the Kunitz family protease inhibitor gene mlt-11 as an NHR-23 target. We identified NHR-23-binding sites that are necessary and sufficient for epithelial expression. mlt-11 is necessary to pattern every layer of the adult cuticle, suggesting a broad patterning role prior to the formation of the mature cuticle. MLT-11::mNeonGreen::3xFLAG transiently localized to the aECM in the cuticle and embryo. It was also detected in lining openings to the exterior (vulva, rectum, mouth). Reduction of mlt-11 function disrupted the barrier function of the cuticle. Tissue-specific RNAi suggested mlt-11 activity is primarily necessary in seam cells and we observed alae and seam cell fusion defects upon mlt-11 inactivation. Predicted mlt-11 null mutations caused fully penetrant embryonic lethality and elongation defects suggesting mlt-11 also plays an important role in patterning the embryonic sheath. Finally, we found that mlt-11 inactivation suppressed the blistered cuticle phenotype of mutants of bli-4 mutants, a subtilisin protease gene but did not affect BLI-4::sfGFP expression. These data could suggest that MLT-11 may be necessary to assure proper levels of BLI-4 activity.
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Affiliation(s)
- James Matthew Ragle
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Ariela Turzo
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Max T. Levenson
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Keya Jonnalagadda
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Anton Jackson
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - An A. Vo
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Vivian T. Pham
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Jordan D. Ward
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
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9
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Spangler RK, Ashley GE, Braun K, Wruck D, Ramos-Coronado A, Ragle JM, Iesmantavicius V, Hess D, Partch CL, Großhans H, Ward JD. A conserved chronobiological complex times C. elegans development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.09.593322. [PMID: 38766223 PMCID: PMC11100808 DOI: 10.1101/2024.05.09.593322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
The mammalian PAS-domain protein PERIOD (PER) and its C. elegans orthologue LIN-42 have been proposed to constitute an evolutionary link between two distinct, circadian and developmental, timing systems. However, while the function of PER in animal circadian rhythms is well understood molecularly and mechanistically, this is not true for the function of LIN-42 in timing rhythmic development. Here, using targeted deletions, we find that the LIN-42 PAS domains are dispensable for the protein's function in timing molts. Instead, we observe arrhythmic molts upon deletion of a distinct sequence element, conserved with PER. We show that this element mediates stable binding to KIN-20, the C. elegans CK1δ/ε orthologue. We demonstrate that CK1δ phosphorylates LIN-42 and define two conserved helical motifs, CK1δ-binding domain A (CK1BD-A) and CK1BD-B, that have distinct roles in controlling CK1δ-binding and kinase activity in vitro. KIN-20 and the LIN-42 CK1BD are required for proper molting timing in vivo. These interactions mirror the central role of a stable circadian PER-CK1 complex in setting a robust ~24-hour period. Hence, our results establish LIN-42/PER - KIN-20/CK1δ/ε as a functionally conserved signaling module of two distinct chronobiological systems.
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Affiliation(s)
- Rebecca K Spangler
- Department of Chemistry and Biochemistry, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Guinevere E Ashley
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Kathrin Braun
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Daniel Wruck
- Department of Chemistry and Biochemistry, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Andrea Ramos-Coronado
- Department of Chemistry and Biochemistry, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - James Matthew Ragle
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | | | - Daniel Hess
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
| | - Carrie L Partch
- Department of Chemistry and Biochemistry, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Helge Großhans
- Friedrich Miescher Institute for Biomedical Research, 4058 Basel, Switzerland
- University of Basel, 4002 Basel, Switzerland
| | - Jordan D Ward
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
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10
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Torzone SK, Breen PC, Cohen NR, Simmons KN, Dowen RH. The TWK-26 potassium channel governs nutrient absorption in the C. elegans intestine. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.06.592787. [PMID: 38766028 PMCID: PMC11100751 DOI: 10.1101/2024.05.06.592787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Ion channels are necessary for proper water and nutrient absorption in the intestine, which supports cellular metabolism and organismal growth. While a role for Na + co-transporters and pumps in intestinal nutrient absorption is well defined, how individual K + uniporters function to maintain ion homeostasis is poorly understood. Using Caenorhabditis elegans , we show that a gain-of-function mutation in twk-26 , which encodes a two-pore domain K + ion channel orthologous to human KCNK3, facilitates nutrient absorption and suppresses the metabolic and developmental defects displayed by impaired intestinal MAP Kinase (MAPK) signaling. Mutations in drl-1 and flr-4, which encode two components of this MAPK pathway, cause severe growth defects, reduced lipid storage, and a dramatic increase in autophagic lysosomes, which mirror dietary restriction phenotypes. Additionally, these MAPK mutants display structural defects of the intestine and an impaired defecation motor program. We find that activation of TWK-26 reverses the dietary restriction-like state of the MAPK mutants by restoring intestinal nutrient absorption without correcting the intestinal bloating or defecation defects. This study provides unique insight into the mechanisms by which intestinal K + ion channels support intestinal metabolic homeostasis.
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11
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Gao L, Ardiel E, Nurrish S, Kaplan JM. Voltage-induced calcium release in Caenorhabditis elegans body muscles. Proc Natl Acad Sci U S A 2024; 121:e2317753121. [PMID: 38687794 PMCID: PMC11087772 DOI: 10.1073/pnas.2317753121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2023] [Accepted: 04/03/2024] [Indexed: 05/02/2024] Open
Abstract
Type 1 voltage-activated calcium channels (CaV1) in the plasma membrane trigger calcium release from the sarcoplasmic reticulum (SR) by two mechanisms. In voltage-induced calcium release (VICR), CaV1 voltage sensing domains are directly coupled to ryanodine receptors (RYRs), an SR calcium channel. In calcium-induced calcium release (CICR), calcium ions flowing through activated CaV1 channels bind and activate RYR channels. VICR is thought to occur exclusively in vertebrate skeletal muscle while CICR occurs in all other muscles (including all invertebrate muscles). Here, we use calcium-activated SLO-2 potassium channels to analyze CaV1-SR coupling in Caenorhabditis elegans body muscles. SLO-2 channels were activated by both VICR and external calcium. VICR-mediated SLO-2 activation requires two SR calcium channels (RYRs and IP3 Receptors), JPH-1/Junctophilin, a PDZ (PSD95, Dlg1, ZO-1 domain) binding domain (PBD) at EGL-19/CaV1's carboxy-terminus, and SHN-1/Shank (a scaffolding protein that binds EGL-19's PBD). Thus, VICR occurs in invertebrate muscles.
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Affiliation(s)
- Luna Gao
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA02114
- Department of Neurobiology, Harvard Medical School, Boston, MA02115
| | - Evan Ardiel
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA02114
- Department of Neurobiology, Harvard Medical School, Boston, MA02115
| | - Stephen Nurrish
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA02114
- Department of Neurobiology, Harvard Medical School, Boston, MA02115
| | - Joshua M. Kaplan
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA02114
- Department of Neurobiology, Harvard Medical School, Boston, MA02115
- Program in Neuroscience, Harvard Medical School, Boston, MA02115
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12
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VanDerMolen KR, Newman MA, Breen PC, Huff LA, Dowen RH. Non-cell-autonomous regulation of mTORC2 by Hedgehog signaling maintains lipid homeostasis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.06.592795. [PMID: 38766075 PMCID: PMC11100691 DOI: 10.1101/2024.05.06.592795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Organisms must appropriately allocate energetic resources between essential cellular processes to maintain homeostasis and in turn, maximize fitness. The nutritional and homeostatic regulators of energy homeostasis have been studied in detail; however, how developmental signals might impinge on these pathways to govern cellular metabolism is poorly understood. Here, we identify a non-canonical role for Hedgehog (Hh), a classic regulator of development, in maintaining intestinal lipid homeostasis in C. elegans . We find that expression of two Hh ligands, GRD-3 and GRD-4, is controlled by the LIN-29/EGR transcription factor in the hypodermis, where the Hh secretion factor CHE-14/Dispatched also facilitates non-cell autonomous Hh signaling. We demonstrate, using C. elegans and mouse hepatocytes, that Hh metabolic regulation does not occur through the canonical Hh transcription factor, TRA-1/GLI, but rather through non-canonical signaling that engages mTOR Complex 2 (mTORC2) in the intestine. Hh mutants display impaired lipid homeostasis, including reduced lipoprotein synthesis and fat accumulation, decreased growth, and upregulation of autophagy factors, mimicking loss of mTORC2. Additionally, we found that Hh inhibits p38 MAPK signaling in parallel to mTORC2 activation and that both pathways act together to modulate of lipid homeostasis. Our findings show a non-canonical role for Hedgehog signaling in lipid metabolism via regulation of core homeostatic pathways and reveal a new mechanism by which developmental timing events govern metabolic decisions.
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13
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Wu Y, Ding C, Sharif B, Weinreb A, Swaim G, Hao H, Yogev S, Watanabe S, Hammarlund M. Polarized localization of kinesin-1 and RIC-7 drives axonal mitochondria anterograde transport. J Cell Biol 2024; 223:e202305105. [PMID: 38470363 PMCID: PMC10932739 DOI: 10.1083/jcb.202305105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 12/17/2023] [Accepted: 02/26/2024] [Indexed: 03/13/2024] Open
Abstract
Mitochondria transport is crucial for axonal mitochondria distribution and is mediated by kinesin-1-based anterograde and dynein-based retrograde motor complexes. While Miro and Milton/TRAK were identified as key adaptors between mitochondria and kinesin-1, recent studies suggest the presence of additional mechanisms. In C. elegans, ric-7 is the only single gene described so far, other than kinesin-1, that is absolutely required for axonal mitochondria localization. Using CRISPR engineering in C. elegans, we find that Miro is important but is not essential for anterograde traffic, whereas it is required for retrograde traffic. Both the endogenous RIC-7 and kinesin-1 act at the leading end to transport mitochondria anterogradely. RIC-7 binding to mitochondria requires its N-terminal domain and partially relies on MIRO-1, whereas RIC-7 accumulation at the leading end depends on its disordered region, kinesin-1, and metaxin2. We conclude that transport complexes containing kinesin-1 and RIC-7 polarize at the leading edge of mitochondria and are required for anterograde axonal transport in C. elegans.
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Affiliation(s)
- Youjun Wu
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Chen Ding
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Behrang Sharif
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Alexis Weinreb
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Grace Swaim
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Hongyan Hao
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Shaul Yogev
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
| | - Shigeki Watanabe
- Department of Cell Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Marc Hammarlund
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT, USA
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14
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Breen PC, Kanakanui KG, Newman MA, Dowen RH. The F-box protein FBXL-5 governs vitellogenesis and lipid homeostasis in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.18.590113. [PMID: 38712300 PMCID: PMC11071313 DOI: 10.1101/2024.04.18.590113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
The molecular mechanisms that govern the metabolic commitment to reproduction, which often occurs at the expense of somatic reserves, remain poorly understood. We identified the C. elegans F-box protein FBXL-5 as a negative regulator of maternal provisioning of vitellogenin lipoproteins, which mediate the transfer of intestinal lipids to the germline. Mutations in fbxl-5 partially suppress the vitellogenesis defects observed in the heterochronic mutants lin-4 and lin-29, both of which ectopically express fbxl-5 at the adult developmental stage. FBXL-5 functions in the intestine to negatively regulate expression of the vitellogenin genes; and consistently, intestine-specific over-expression of FBXL-5 is sufficient to inhibit vitellogenesis, restrict lipid accumulation, and shorten lifespan. Our epistasis analyses suggest that fbxl-5 functions in concert with cul-6 , a cullin gene, and the Skp1-related gene skr-3 to regulate vitellogenesis. Additionally, fbxl-5 acts genetically upstream of rict-1 , which encodes the core mTORC2 protein Rictor, to govern vitellogenesis. Together, our results reveal an unexpected role for a SCF ubiquitin-ligase complex in controlling intestinal lipid homeostasis by engaging mTORC2 signaling.
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15
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Sandhu A, Lyu X, Wan X, Meng X, Tang NH, Gonzalez G, Syed IN, Chen L, Jin Y, Chisholm AD. The microtubule regulator EFA-6 forms spatially restricted cortical foci dependent on its intrinsically disordered region and interactions with tubulins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.14.588158. [PMID: 38645057 PMCID: PMC11030407 DOI: 10.1101/2024.04.14.588158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Microtubules (MTs) are dynamic components of the cytoskeleton and play essential roles in morphogenesis and maintenance of tissue and cell integrity. Despite recent advances in understanding MT ultrastructure, organization, and growth control, how cells regulate MT organization at the cell cortex remains poorly understood. The EFA-6/EFA6 proteins are recently identified membrane-associated proteins that inhibit cortical MT dynamics. Here, combining visualization of endogenously tagged C. elegans EFA-6 with genetic screening, we uncovered tubulin-dependent regulation of EFA-6 patterning. In the mature epidermal epithelium, EFA-6 forms punctate foci in specific regions of the apical cortex, dependent on its intrinsically disordered region (IDR). We further show the EFA-6 IDR is sufficient to form biomolecular condensates in vitro. In screens for mutants with altered GFP::EFA-6 localization, we identified a novel gain-of-function (gf) mutation in an α-tubulin tba-1 that induces ectopic EFA-6 foci in multiple cell types. tba-1(gf) animals exhibit temperature-sensitive embryonic lethality, which is partially suppressed by efa-6(lf), indicating the interaction between tubulins and EFA-6 is important for normal development. TBA-1(gf) shows reduced incorporation into filamentous MTs but has otherwise mild effects on cellular MT organization. The ability of TBA-1(gf) to trigger ectopic EFA-6 foci formation requires β-tubulin TBB-2 and the chaperon EVL-20/Arl2. The tba-1(gf)-induced EFA-6 foci display slower turnover, contain the MT-associated protein TAC-1/TACC, and require the EFA-6 MTED. Our results reveal a novel crosstalk between cellular tubulins and cortical MT regulators in vivo.
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Affiliation(s)
- Anjali Sandhu
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, CA 92093 USA
| | - Xiaohui Lyu
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, CA 92093 USA
| | - Xinghaoyun Wan
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, CA 92093 USA
| | - Xuefeng Meng
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, CA 92093 USA
| | - Ngang Heok Tang
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California San Diego, CA 92093 USA
| | - Gilberto Gonzalez
- Barshop Institute for Longevity and Aging Studies, Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Ishana N. Syed
- Barshop Institute for Longevity and Aging Studies, Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Lizhen Chen
- Barshop Institute for Longevity and Aging Studies, Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Yishi Jin
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, CA 92093 USA
| | - Andrew D. Chisholm
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, CA 92093 USA
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California San Diego, CA 92093 USA
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16
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Pliota P, Marvanova H, Koreshova A, Kaufman Y, Tikanova P, Krogull D, Hagmüller A, Widen SA, Handler D, Gokcezade J, Duchek P, Brennecke J, Ben-David E, Burga A. Selfish conflict underlies RNA-mediated parent-of-origin effects. Nature 2024; 628:122-129. [PMID: 38448590 PMCID: PMC10990930 DOI: 10.1038/s41586-024-07155-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 02/02/2024] [Indexed: 03/08/2024]
Abstract
Genomic imprinting-the non-equivalence of maternal and paternal genomes-is a critical process that has evolved independently in many plant and mammalian species1,2. According to kinship theory, imprinting is the inevitable consequence of conflictive selective forces acting on differentially expressed parental alleles3,4. Yet, how these epigenetic differences evolve in the first place is poorly understood3,5,6. Here we report the identification and molecular dissection of a parent-of-origin effect on gene expression that might help to clarify this fundamental question. Toxin-antidote elements (TAs) are selfish elements that spread in populations by poisoning non-carrier individuals7-9. In reciprocal crosses between two Caenorhabditis tropicalis wild isolates, we found that the slow-1/grow-1 TA is specifically inactive when paternally inherited. This parent-of-origin effect stems from transcriptional repression of the slow-1 toxin by the PIWI-interacting RNA (piRNA) host defence pathway. The repression requires PIWI Argonaute and SET-32 histone methyltransferase activities and is transgenerationally inherited via small RNAs. Remarkably, when slow-1/grow-1 is maternally inherited, slow-1 repression is halted by a translation-independent role of its maternal mRNA. That is, slow-1 transcripts loaded into eggs-but not SLOW-1 protein-are necessary and sufficient to counteract piRNA-mediated repression. Our findings show that parent-of-origin effects can evolve by co-option of the piRNA pathway and hinder the spread of selfish genes that require sex for their propagation.
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Affiliation(s)
- Pinelopi Pliota
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Hana Marvanova
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Alevtina Koreshova
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Yotam Kaufman
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Polina Tikanova
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Daniel Krogull
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, Vienna, Austria
| | - Andreas Hagmüller
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Sonya A Widen
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Dominik Handler
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Joseph Gokcezade
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Peter Duchek
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Julius Brennecke
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Eyal Ben-David
- Department of Biochemistry and Molecular Biology, Institute for Medical Research Israel-Canada, The Hebrew University of Jerusalem, Jerusalem, Israel
- Illumina Artificial Intelligence Laboratory, Illumina, San Diego, CA, USA
| | - Alejandro Burga
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), Vienna, Austria.
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17
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Brown HE, Varderesian HV, Keane SA, Ryder SP. The mex-3 3' untranslated region is essential for reproduction during temperature stress. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.01.587367. [PMID: 38798418 PMCID: PMC11123400 DOI: 10.1101/2024.04.01.587367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Organisms must sense temperature and modify their physiology to ensure survival during environmental stress. Elevated temperature leads to reduced fertility in most sexually reproducing organisms. Maternally supplied mRNAs are required for embryogenesis. They encode proteins that govern early events in embryonic patterning. RNA-binding proteins (RBPs) are major effectors of maternal mRNA regulation. MEX-3 is a conserved RBP essential for anterior patterning of Caenorhabditis elegans embryos. We previously demonstrated that the mex-3 3' untranslated region (3'UTR) represses MEX-3 abundance in the germline yet is dispensable for fertility. Here, we show that the 3'UTR becomes essential during thermal stress. Deletion of the 3'UTR causes a highly penetrant temperature sensitive embryonic lethality phenotype distinct from a mex-3 null. Loss of the 3'UTR decreases MEX-3 abundance specifically in maturing oocytes and early embryos experiencing temperature stress, suggesting a mechanism that regulates MEX-3 abundance at the oocyte-to-embryo transition is sensitive to temperature. We propose that a primary role of the mex-3 3'UTR is to buffer MEX-3 expression to ensure viability during fluctuating temperature. We hypothesize that a major role of maternally supplied mRNAs is to ensure robust expression of key cell fate determinants in uncertain conditions.
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18
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DuMez-Kornegay RN, Baker LS, Morris AJ, DeLoach WLM, Dowen RH. Kombucha Tea-associated microbes remodel host metabolic pathways to suppress lipid accumulation. PLoS Genet 2024; 20:e1011003. [PMID: 38547054 PMCID: PMC10977768 DOI: 10.1371/journal.pgen.1011003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Accepted: 02/22/2024] [Indexed: 04/02/2024] Open
Abstract
The popularity of the ancient, probiotic-rich beverage Kombucha Tea (KT) has surged in part due to its purported health benefits, which include protection against metabolic diseases; however, these claims have not been rigorously tested and the mechanisms underlying host response to the probiotics in KT are unknown. Here, we establish a reproducible method to maintain C. elegans on a diet exclusively consisting of Kombucha Tea-associated microbes (KTM), which mirrors the microbial community found in the fermenting culture. KT microbes robustly colonize the gut of KTM-fed animals and confer normal development and fecundity. Intriguingly, animals consuming KTMs display a marked reduction in total lipid stores and lipid droplet size. We find that the reduced fat accumulation phenotype is not due to impaired nutrient absorption, but rather it is sustained by a programed metabolic response in the intestine of the host. KTM consumption triggers widespread transcriptional changes within core lipid metabolism pathways, including upregulation of a suite of lysosomal lipase genes that are induced during lipophagy. The elevated lysosomal lipase activity, coupled with a decrease in lipid droplet biogenesis, is partially required for the reduction in host lipid content. We propose that KTM consumption stimulates a fasting-like response in the C. elegans intestine by rewiring transcriptional programs to promote lipid utilization. Our results provide mechanistic insight into how the probiotics in Kombucha Tea reshape host metabolism and how this popular beverage may impact human metabolism.
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Affiliation(s)
- Rachel N. DuMez-Kornegay
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Lillian S. Baker
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Alexis J. Morris
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Whitney L. M. DeLoach
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Robert H. Dowen
- Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
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19
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Tocchini C, Mango SE. An adapted MS2-MCP system to visualize endogenous cytoplasmic mRNA with live imaging in Caenorhabditis elegans. PLoS Biol 2024; 22:e3002526. [PMID: 38427703 PMCID: PMC10936773 DOI: 10.1371/journal.pbio.3002526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 03/13/2024] [Accepted: 01/29/2024] [Indexed: 03/03/2024] Open
Abstract
Live imaging of RNA molecules constitutes an invaluable means to track the dynamics of mRNAs, but live imaging in Caenorhabditis elegans has been difficult to achieve. Endogenous transcripts have been observed in nuclei, but endogenous mRNAs have not been detected in the cytoplasm, and functional mRNAs have not been generated. Here, we have adapted live imaging methods to visualize mRNA in embryonic cells. We have tagged endogenous transcripts with MS2 hairpins in the 3' untranslated region (UTR) and visualized them after adjusting MS2 Coat Protein (MCP) expression. A reduced number of these transcripts accumulates in the cytoplasm, leading to loss-of-function phenotypes. In addition, during epithelial morphogenesis, MS2-tagged mRNAs for dlg-1 fail to associate with the adherens junction, as observed for untagged, endogenous mRNAs. These defects are reversed by inactivating the nonsense-mediated decay pathway. RNA accumulates in the cytoplasm, mutant phenotypes are rescued, and dlg-1 RNA associates with the adherens junction. These data suggest that MS2 repeats can induce the degradation of endogenous RNAs and alter their cytoplasmic distribution. Although our focus is RNAs expressed in epithelial cells during morphogenesis, we find that this method can be applied to other cell types and stages.
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20
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Warnhoff K, Bhattacharya S, Snoozy J, Breen PC, Ruvkun G. Hypoxia-inducible factor induces cysteine dioxygenase and promotes cysteine homeostasis in Caenorhabditis elegans. eLife 2024; 12:RP89173. [PMID: 38349720 PMCID: PMC10942545 DOI: 10.7554/elife.89173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2024] Open
Abstract
Dedicated genetic pathways regulate cysteine homeostasis. For example, high levels of cysteine activate cysteine dioxygenase, a key enzyme in cysteine catabolism in most animal and many fungal species. The mechanism by which cysteine dioxygenase is regulated is largely unknown. In an unbiased genetic screen for mutations that activate cysteine dioxygenase (cdo-1) in the nematode Caenorhabditis elegans, we isolated loss-of-function mutations in rhy-1 and egl-9, which encode proteins that negatively regulate the stability or activity of the oxygen-sensing hypoxia inducible transcription factor (hif-1). EGL-9 and HIF-1 are core members of the conserved eukaryotic hypoxia response. However, we demonstrate that the mechanism of HIF-1-mediated induction of cdo-1 is largely independent of EGL-9 prolyl hydroxylase activity and the von Hippel-Lindau E3 ubiquitin ligase, the classical hypoxia signaling pathway components. We demonstrate that C. elegans cdo-1 is transcriptionally activated by high levels of cysteine and hif-1. hif-1-dependent activation of cdo-1 occurs downstream of an H2S-sensing pathway that includes rhy-1, cysl-1, and egl-9. cdo-1 transcription is primarily activated in the hypodermis where it is also sufficient to drive sulfur amino acid metabolism. Thus, the regulation of cdo-1 by hif-1 reveals a negative feedback loop that maintains cysteine homeostasis. High levels of cysteine stimulate the production of an H2S signal. H2S then acts through the rhy-1/cysl-1/egl-9 signaling pathway to increase HIF-1-mediated transcription of cdo-1, promoting degradation of cysteine via CDO-1.
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Affiliation(s)
- Kurt Warnhoff
- Pediatrics and Rare Diseases Group, Sanford ResearchSioux FallsUnited States
- Department of Pediatrics, Sanford School of Medicine, University of South DakotaSioux FallsUnited States
| | | | - Jennifer Snoozy
- Pediatrics and Rare Diseases Group, Sanford ResearchSioux FallsUnited States
| | - Peter C Breen
- Department of Molecular Biology, Massachusetts General HospitalBostonUnited States
| | - Gary Ruvkun
- Department of Molecular Biology, Massachusetts General HospitalBostonUnited States
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21
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Meisel JD, Miranda M, Skinner OS, Wiesenthal PP, Wellner SM, Jourdain AA, Ruvkun G, Mootha VK. Hypoxia and intra-complex genetic suppressors rescue complex I mutants by a shared mechanism. Cell 2024; 187:659-675.e18. [PMID: 38215760 PMCID: PMC10919891 DOI: 10.1016/j.cell.2023.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 09/09/2023] [Accepted: 12/05/2023] [Indexed: 01/14/2024]
Abstract
The electron transport chain (ETC) of mitochondria, bacteria, and archaea couples electron flow to proton pumping and is adapted to diverse oxygen environments. Remarkably, in mice, neurological disease due to ETC complex I dysfunction is rescued by hypoxia through unknown mechanisms. Here, we show that hypoxia rescue and hyperoxia sensitivity of complex I deficiency are evolutionarily conserved to C. elegans and are specific to mutants that compromise the electron-conducting matrix arm. We show that hypoxia rescue does not involve the hypoxia-inducible factor pathway or attenuation of reactive oxygen species. To discover the mechanism, we use C. elegans genetic screens to identify suppressor mutations in the complex I accessory subunit NDUFA6/nuo-3 that phenocopy hypoxia rescue. We show that NDUFA6/nuo-3(G60D) or hypoxia directly restores complex I forward activity, with downstream rescue of ETC flux and, in some cases, complex I levels. Additional screens identify residues within the ubiquinone binding pocket as being required for the rescue by NDUFA6/nuo-3(G60D) or hypoxia. This reveals oxygen-sensitive coupling between an accessory subunit and the quinone binding pocket of complex I that can restore forward activity in the same manner as hypoxia.
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Affiliation(s)
- Joshua D Meisel
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Maria Miranda
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Owen S Skinner
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Presli P Wiesenthal
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA
| | - Sandra M Wellner
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Alexis A Jourdain
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Gary Ruvkun
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA.
| | - Vamsi K Mootha
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA; Harvard Medical School, Boston, MA 02115, USA; Broad Institute, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Massachusetts General Hospital, Boston, MA 02114, USA.
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22
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Pooranachithra M, Jyo EM, Ernst AM, Chisholm AD. C. elegans epicuticlins define specific compartments in the apical extracellular matrix and function in wound repair. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.12.575393. [PMID: 38260454 PMCID: PMC10802564 DOI: 10.1101/2024.01.12.575393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The apical extracellular matrix (aECM) of external epithelia often contains lipid-rich outer layers that contribute to permeability barrier function. The external aECM of nematode is known as the cuticle and contains an external lipid-rich layer, the epicuticle. Epicuticlins are a family of tandem repeat proteins originally identified as components of the insoluble fraction of the cuticular aECM and thought to localize in or near epicuticle. However, there has been little in vivo analysis of epicuticlins. Here, we report the localization analysis of the three C. elegans epicuticlins (EPIC proteins) using fluorescent protein knock-ins to visualize endogenously expressed proteins, and further examine their in vivo function using genetic null mutants. By TIRF microscopy, we find that EPIC-1 and EPIC-2 localize to the surface of the cuticle in larval and adult stages in close proximity to the outer lipid layer. EPIC-1 and EPIC-2 also localize to interfacial cuticles and adult-specific cuticle struts. EPIC-3 expression is restricted to the stress-induced dauer stage, where it localizes to interfacial aECM in the buccal cavity. Strikingly, skin wounding in the adult induces epic-3 expression, and EPIC-3::mNG localizes to wound scars. Null mutants lacking one, two, or all three EPIC proteins display reduced survival after skin wounding yet are viable with low penetrance defects in epidermal morphogenesis. Our results suggest EPIC proteins define specific aECM compartments and have roles in wound repair.
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Affiliation(s)
- Murugesan Pooranachithra
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093
| | - Erin M Jyo
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093
| | - Andreas M Ernst
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093
| | - Andrew D Chisholm
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093
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23
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Kudron M, Gevirtzman L, Victorsen A, Lear BC, Gao J, Xu J, Samanta S, Frink E, Tran-Pearson A, Huynh C, Vafeados D, Hammonds A, Fisher W, Wall M, Wesseling G, Hernandez V, Lin Z, Kasparian M, White K, Allada R, Gerstein M, Hillier L, Celniker SE, Reinke V, Waterston RH. Binding profiles for 954 Drosophila and C. elegans transcription factors reveal tissue specific regulatory relationships. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.18.576242. [PMID: 38293065 PMCID: PMC10827215 DOI: 10.1101/2024.01.18.576242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
A catalog of transcription factor (TF) binding sites in the genome is critical for deciphering regulatory relationships. Here we present the culmination of the modERN (model organism Encyclopedia of Regulatory Networks) consortium that systematically assayed TF binding events in vivo in two major model organisms, Drosophila melanogaster (fly) and Caenorhabditis elegans (worm). We describe key features of these datasets, comprising 604 TFs identifying 3.6M sites in the fly and 350 TFs identifying 0.9 M sites in the worm. Applying a machine learning model to these data identifies sets of TFs with a prominent role in promoting target gene expression in specific cell types. TF binding data are available through the ENCODE Data Coordinating Center and at https://epic.gs.washington.edu/modERNresource, which provides access to processed and summary data, as well as widgets to probe cell type-specific TF-target relationships. These data are a rich resource that should fuel investigations into TF function during development.
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Affiliation(s)
- Michelle Kudron
- Department of Genetics, Yale University, New Haven, Connecticut 06520
| | - Louis Gevirtzman
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington 98195
| | - Alec Victorsen
- Department of Laboratory Medicine & Pathology, University of Minnesota, Minneapolis, MN 55455
| | - Bridget C. Lear
- Department of Neurobiology, Northwestern University, Evanston IL 60208
| | - Jiahao Gao
- Program in Computational Biology and Bioinformatics, Yale University, New Haven, Connecticut 06520
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520
| | - Jinrui Xu
- Department of Biology, Howard University, Washington, District of Columbia 20059, USA
- Center for Applied Data Science and Analytics, Howard University, Washington, District of Columbia 20059, USA
| | - Swapna Samanta
- Department of Genetics, Yale University, New Haven, Connecticut 06520
| | - Emily Frink
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington 98195
| | - Adri Tran-Pearson
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington 98195
| | - Chau Huynh
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington 98195
| | - Dionne Vafeados
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington 98195
| | - Ann Hammonds
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - William Fisher
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Martha Wall
- Institute for Genomics and Systems Biology, Department of Human Genetics, University of Chicago, Illinois 60637
| | - Greg Wesseling
- Department of Neurobiology, Northwestern University, Evanston IL 60208
| | - Vanessa Hernandez
- Department of Neurobiology, Northwestern University, Evanston IL 60208
| | - Zhichun Lin
- Department of Neurobiology, Northwestern University, Evanston IL 60208
| | - Mary Kasparian
- Department of Neurobiology, Northwestern University, Evanston IL 60208
| | - Kevin White
- Department of Biochemistry and Precision Medicine Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597
| | - Ravi Allada
- Department of Neurobiology, Northwestern University, Evanston IL 60208
| | - Mark Gerstein
- Program in Computational Biology and Bioinformatics, Yale University, New Haven, Connecticut 06520
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06520
- Department of Statistics and Data Science, Yale University, New Haven, Connecticut 06520, USA
| | - LaDeana Hillier
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington 98195
| | - Susan E. Celniker
- Division of Biological Systems and Engineering, Lawrence Berkeley National Laboratory, Berkeley, California 94720
| | - Valerie Reinke
- Department of Genetics, Yale University, New Haven, Connecticut 06520
| | - Robert H. Waterston
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, Washington 98195
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24
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Majeed M, Han H, Zhang K, Cao WX, Liao CP, Hobert O, Lu H. Toolkits for detailed and high-throughput interrogation of synapses in C. elegans. eLife 2024; 12:RP91775. [PMID: 38224479 PMCID: PMC10945580 DOI: 10.7554/elife.91775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2024] Open
Abstract
Visualizing synaptic connectivity has traditionally relied on time-consuming electron microscopy-based imaging approaches. To scale the analysis of synaptic connectivity, fluorescent protein-based techniques have been established, ranging from the labeling of specific pre- or post-synaptic components of chemical or electrical synapses to transsynaptic proximity labeling technology such as GRASP and iBLINC. In this paper, we describe WormPsyQi, a generalizable image analysis pipeline that automatically quantifies synaptically localized fluorescent signals in a high-throughput and robust manner, with reduced human bias. We also present a resource of 30 transgenic strains that label chemical or electrical synapses throughout the nervous system of the nematode Caenorhabditis elegans, using CLA-1, RAB-3, GRASP (chemical synapses), or innexin (electrical synapse) reporters. We show that WormPsyQi captures synaptic structures in spite of substantial heterogeneity in neurite morphology, fluorescence signal, and imaging parameters. We use these toolkits to quantify multiple obvious and subtle features of synapses - such as number, size, intensity, and spatial distribution of synapses - in datasets spanning various regions of the nervous system, developmental stages, and sexes. Although the pipeline is described in the context of synapses, it may be utilized for other 'punctate' signals, such as fluorescently tagged neurotransmitter receptors and cell adhesion molecules, as well as proteins in other subcellular contexts. By overcoming constraints on time, sample size, cell morphology, and phenotypic space, this work represents a powerful resource for further analysis of synapse biology in C. elegans.
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Affiliation(s)
- Maryam Majeed
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia UniversityNew YorkUnited States
| | - Haejun Han
- School of Electrical and Computer Engineering, Georgia Institute of TechnologyAtlantaUnited States
- The Parker H Petit Institute of Bioengineering and Bioscience, Georgia Institute of TechnologyAtlantaUnited States
| | - Keren Zhang
- School of Chemical and Biomolecular Engineering, Georgia Institute of TechnologyAtlantaUnited States
| | - Wen Xi Cao
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia UniversityNew YorkUnited States
| | - Chien-Po Liao
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia UniversityNew YorkUnited States
| | - Oliver Hobert
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia UniversityNew YorkUnited States
| | - Hang Lu
- The Parker H Petit Institute of Bioengineering and Bioscience, Georgia Institute of TechnologyAtlantaUnited States
- School of Chemical and Biomolecular Engineering, Georgia Institute of TechnologyAtlantaUnited States
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25
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Lemieux GA, Yoo S, Lin L, Vohra M, Ashrafi K. The steroid hormone ADIOL promotes learning by reducing neural kynurenic acid levels. Genes Dev 2023; 37:998-1016. [PMID: 38092521 PMCID: PMC10760639 DOI: 10.1101/gad.350745.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 11/22/2023] [Indexed: 12/28/2023]
Abstract
Reductions in brain kynurenic acid levels, a neuroinhibitory metabolite, improve cognitive function in diverse organisms. Thus, modulation of kynurenic acid levels is thought to have therapeutic potential in a range of brain disorders. Here we report that the steroid 5-androstene 3β, 17β-diol (ADIOL) reduces kynurenic acid levels and promotes associative learning in Caenorhabditis elegans We identify the molecular mechanisms through which ADIOL links peripheral metabolic pathways to neural mechanisms of learning capacity. Moreover, we show that in aged animals, which normally experience rapid cognitive decline, ADIOL improves learning capacity. The molecular mechanisms that underlie the biosynthesis of ADIOL as well as those through which it promotes kynurenic acid reduction are conserved in mammals. Thus, rather than a minor intermediate in the production of sex steroids, ADIOL is an endogenous hormone that potently regulates learning capacity by causing reductions in neural kynurenic acid levels.
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Affiliation(s)
- George A Lemieux
- Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
| | - Shinja Yoo
- Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
| | - Lin Lin
- Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
| | - Mihir Vohra
- Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
| | - Kaveh Ashrafi
- Department of Physiology, University of California, San Francisco, San Francisco, California 94143, USA
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26
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Pu L, Wang J, Lu Q, Nilsson L, Philbrook A, Pandey A, Zhao L, Schendel RV, Koh A, Peres TV, Hashi WH, Myint SL, Williams C, Gilthorpe JD, Wai SN, Brown A, Tijsterman M, Sengupta P, Henriksson J, Chen C. Dissecting the genetic landscape of GPCR signaling through phenotypic profiling in C. elegans. Nat Commun 2023; 14:8410. [PMID: 38110404 PMCID: PMC10728192 DOI: 10.1038/s41467-023-44177-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 12/04/2023] [Indexed: 12/20/2023] Open
Abstract
G protein-coupled receptors (GPCRs) mediate responses to various extracellular and intracellular cues. However, the large number of GPCR genes and their substantial functional redundancy make it challenging to systematically dissect GPCR functions in vivo. Here, we employ a CRISPR/Cas9-based approach, disrupting 1654 GPCR-encoding genes in 284 strains and mutating 152 neuropeptide-encoding genes in 38 strains in C. elegans. These two mutant libraries enable effective deorphanization of chemoreceptors, and characterization of receptors for neuropeptides in various cellular processes. Mutating a set of closely related GPCRs in a single strain permits the assignment of functions to GPCRs with functional redundancy. Our analyses identify a neuropeptide that interacts with three receptors in hypoxia-evoked locomotory responses, unveil a collection of regulators in pathogen-induced immune responses, and define receptors for the volatile food-related odorants. These results establish our GPCR and neuropeptide mutant libraries as valuable resources for the C. elegans community to expedite studies of GPCR signaling in multiple contexts.
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Affiliation(s)
- Longjun Pu
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Jing Wang
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Qiongxuan Lu
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Lars Nilsson
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Alison Philbrook
- Department of Biology, MS 008, Brandeis University, 415 South Street, Waltham, MA, 02454, USA
| | - Anjali Pandey
- Department of Biology, MS 008, Brandeis University, 415 South Street, Waltham, MA, 02454, USA
| | - Lina Zhao
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Robin van Schendel
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Alan Koh
- MRC Laboratory of Medical Sciences, London, W12 0HS, UK
- Institute of Clinical Sciences, Imperial College London, London, UK
| | - Tanara V Peres
- MRC Laboratory of Medical Sciences, London, W12 0HS, UK
- Institute of Clinical Sciences, Imperial College London, London, UK
| | - Weheliye H Hashi
- MRC Laboratory of Medical Sciences, London, W12 0HS, UK
- Institute of Clinical Sciences, Imperial College London, London, UK
| | - Si Lhyam Myint
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Chloe Williams
- Department of Integrative Medical Biology, Umeå University, Umeå, Sweden
| | | | - Sun Nyunt Wai
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - Andre Brown
- MRC Laboratory of Medical Sciences, London, W12 0HS, UK
- Institute of Clinical Sciences, Imperial College London, London, UK
| | - Marcel Tijsterman
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Piali Sengupta
- Department of Biology, MS 008, Brandeis University, 415 South Street, Waltham, MA, 02454, USA
| | - Johan Henriksson
- Department of Molecular Biology, Umeå University, Umeå, Sweden.
- Umeå Centre for Microbial Research (UCMR), Umeå University, Umeå, Sweden.
- Integrated Science Lab (Icelab), Umeå University, Umeå, Sweden.
| | - Changchun Chen
- Department of Molecular Biology, Umeå University, Umeå, Sweden.
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden.
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden.
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27
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Ivanova M, Moss EG. Orthologs of the Caenorhabditis elegans heterochronic genes have divergent functions in Caenorhabditis briggsae. Genetics 2023; 225:iyad177. [PMID: 37788363 PMCID: PMC10697817 DOI: 10.1093/genetics/iyad177] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 05/22/2023] [Accepted: 09/14/2023] [Indexed: 10/05/2023] Open
Abstract
The heterochronic genes of Caenorhabditis elegans comprise the best-studied pathway controlling the timing of tissue and organ formation in an animal. To begin to understand the evolution of this pathway and the significance of the relationships among its components, we characterized 11 Caenorhabditis briggsae orthologs of C. elegans heterochronic genes. Using CRISPR/Cas9, we made a variety of alleles and found that several mutant phenotypes differ in significant ways from those of C. elegans. Although most mutant orthologs displayed defects in developmental timing, their phenotypes could differ in which stages were affected, the penetrance and expressivity of the phenotypes, or by having additional pleiotropies that were not obviously connected to developmental timing. However, when examining pairwise epistasis and synergistic relationships, we found those paralleled the known relationships between their C. elegans orthologs, suggesting that the arrangements of these genes in functional modules are conserved, but the modules' relationships to each other and/or to their targets has drifted since the time of the species' last common ancestor. Furthermore, our investigation has revealed a relationship between this pathway to other aspects of the animal's growth and development, including gonad development, which is relevant to both species.
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Affiliation(s)
- Maria Ivanova
- Department of Molecular Biology, Rowan-Virtua School of Translational Biomedical Engineering and Sciences, Rowan University, Stratford, NJ 08084, USA
| | - Eric G Moss
- Department of Molecular Biology, Rowan University, Stratford, NJ 08084, USA
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28
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McDonald NA, Tao L, Dong MQ, Shen K. SAD-1 kinase controls presynaptic phase separation by relieving SYD-2/Liprin-α autoinhibition. PLoS Biol 2023; 21:e3002421. [PMID: 38048304 PMCID: PMC10695385 DOI: 10.1371/journal.pbio.3002421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 11/06/2023] [Indexed: 12/06/2023] Open
Abstract
Neuronal development orchestrates the formation of an enormous number of synapses that connect the nervous system. In developing presynapses, the core active zone structure has been found to assemble through liquid-liquid phase separation. Here, we find that the phase separation of Caenorhabditis elegans SYD-2/Liprin-α, a key active zone scaffold, is controlled by phosphorylation. We identify the SAD-1 kinase as a regulator of SYD-2 phase separation and determine presynaptic assembly is impaired in sad-1 mutants and increased by overactivation of SAD-1. Using phosphoproteomics, we find SAD-1 phosphorylates SYD-2 on 3 sites that are critical to activate phase separation. Mechanistically, SAD-1 phosphorylation relieves a binding interaction between 2 folded domains in SYD-2 that inhibits phase separation by an intrinsically disordered region (IDR). We find synaptic cell adhesion molecules localize SAD-1 to nascent synapses upstream of active zone formation. We conclude that SAD-1 phosphorylates SYD-2 at developing synapses, activating its phase separation and active zone assembly.
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Affiliation(s)
- Nathan A. McDonald
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Li Tao
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing, People’s Republic of China
| | - Kang Shen
- Department of Biology, Stanford University, Stanford, California, United States of America
- Howard Hughes Medical Institute, Stanford University, Stanford, California, United States of America
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29
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Medwig-Kinney TN, Kinney BA, Martinez MAQ, Yee C, Sirota SS, Mullarkey AA, Somineni N, Hippler J, Zhang W, Shen K, Hammell C, Pani AM, Matus DQ. Dynamic compartmentalization of the pro-invasive transcription factor NHR-67 reveals a role for Groucho in regulating a proliferative-invasive cellular switch in C. elegans. eLife 2023; 12:RP84355. [PMID: 38038410 PMCID: PMC10691804 DOI: 10.7554/elife.84355] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023] Open
Abstract
A growing body of evidence suggests that cell division and basement membrane invasion are mutually exclusive cellular behaviors. How cells switch between proliferative and invasive states is not well understood. Here, we investigated this dichotomy in vivo by examining two cell types in the developing Caenorhabditis elegans somatic gonad that derive from equipotent progenitors, but exhibit distinct cell behaviors: the post-mitotic, invasive anchor cell and the neighboring proliferative, non-invasive ventral uterine (VU) cells. We show that the fates of these cells post-specification are more plastic than previously appreciated and that levels of NHR-67 are important for discriminating between invasive and proliferative behavior. Transcription of NHR-67 is downregulated following post-translational degradation of its direct upstream regulator, HLH-2 (E/Daughterless) in VU cells. In the nuclei of VU cells, residual NHR-67 protein is compartmentalized into discrete punctae that are dynamic over the cell cycle and exhibit liquid-like properties. By screening for proteins that colocalize with NHR-67 punctae, we identified new regulators of uterine cell fate maintenance: homologs of the transcriptional co-repressor Groucho (UNC-37 and LSY-22), as well as the TCF/LEF homolog POP-1. We propose a model in which the association of NHR-67 with the Groucho/TCF complex suppresses the default invasive state in non-invasive cells, which complements transcriptional regulation to add robustness to the proliferative-invasive cellular switch in vivo.
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Affiliation(s)
- Taylor N Medwig-Kinney
- Department of Biochemistry and Cell Biology, Stony Brook UniversityStony BrookUnited States
| | - Brian A Kinney
- Cold Spring Harbor LaboratoryCold Spring HarborUnited States
| | - Michael AQ Martinez
- Department of Biochemistry and Cell Biology, Stony Brook UniversityStony BrookUnited States
| | - Callista Yee
- Howard Hughes Medical Institute, Department of Biology, Stanford UniversityStanfordUnited States
| | - Sydney S Sirota
- Department of Biochemistry and Cell Biology, Stony Brook UniversityStony BrookUnited States
| | - Angelina A Mullarkey
- Department of Biochemistry and Cell Biology, Stony Brook UniversityStony BrookUnited States
| | - Neha Somineni
- Department of Biochemistry and Cell Biology, Stony Brook UniversityStony BrookUnited States
| | - Justin Hippler
- Department of Biochemistry and Cell Biology, Stony Brook UniversityStony BrookUnited States
- Science and Technology Research Program, Smithtown High School EastSt. JamesUnited States
| | - Wan Zhang
- Department of Biochemistry and Cell Biology, Stony Brook UniversityStony BrookUnited States
| | - Kang Shen
- Howard Hughes Medical Institute, Department of Biology, Stanford UniversityStanfordUnited States
| | | | - Ariel M Pani
- Departments of Biology and Cell Biology, University of VirginiaCharlottesvilleUnited States
| | - David Q Matus
- Department of Biochemistry and Cell Biology, Stony Brook UniversityStony BrookUnited States
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30
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Adams JRG, Pooranachithra M, Jyo EM, Zheng SL, Goncharov A, Crew JR, Kramer JM, Jin Y, Ernst AM, Chisholm AD. Nanoscale patterning of collagens in C. elegans apical extracellular matrix. Nat Commun 2023; 14:7506. [PMID: 37980413 PMCID: PMC10657453 DOI: 10.1038/s41467-023-43058-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Accepted: 10/30/2023] [Indexed: 11/20/2023] Open
Abstract
Apical extracellular matrices (aECMs) are complex extracellular compartments that form important interfaces between animals and their environment. In the adult C. elegans cuticle, layers are connected by regularly spaced columnar structures known as struts. Defects in struts result in swelling of the fluid-filled medial cuticle layer ('blistering', Bli). Here we show that three cuticle collagens BLI-1, BLI-2, and BLI-6, play key roles in struts. BLI-1 and BLI-2 are essential for strut formation whereas activating mutations in BLI-6 disrupt strut formation. BLI-1, BLI-2, and BLI-6 precisely colocalize to arrays of puncta in the adult cuticle, corresponding to struts, initially deposited in diffuse stripes adjacent to cuticle furrows. They eventually exhibit tube-like morphology, with the basal ends of BLI-containing struts contact regularly spaced holes in the cuticle. Genetic interaction studies indicate that BLI strut patterning involves interactions with other cuticle components. Our results reveal strut formation as a tractable example of precise aECM patterning at the nanoscale.
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Affiliation(s)
- Jennifer R G Adams
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Murugesan Pooranachithra
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Erin M Jyo
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Sherry Li Zheng
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Alexandr Goncharov
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Jennifer R Crew
- Northwestern University School of Medicine, Department of Cell and Molecular Biology, Chicago, IL, 60611, USA
| | - James M Kramer
- Northwestern University School of Medicine, Department of Cell and Molecular Biology, Chicago, IL, 60611, USA
| | - Yishi Jin
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Andreas M Ernst
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA
| | - Andrew D Chisholm
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA.
- Department of Neurobiology, School of Biological Sciences, University of California San Diego, La Jolla, CA, 92093, USA.
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31
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Pu L, Nilsson L, Chen C, Wang J. Iterative editing of multiple genes using CRISPR/Cas9 in C. elegans. MICROPUBLICATION BIOLOGY 2023; 2023:10.17912/micropub.biology.000898. [PMID: 38033425 PMCID: PMC10685264 DOI: 10.17912/micropub.biology.000898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Figures] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 09/22/2023] [Accepted: 10/24/2023] [Indexed: 12/02/2023]
Abstract
Certain sets of genes are derived from gene duplication and share substantial sequence similarity in C. elegans , presenting a significant challenge in determining the specific roles of each gene and their collective impact on cellular processes. Here, we show that a collection of genes can be disrupted in a single animal via multiple rounds of CRISPR/Cas9 mediated genome editing. We found that up to three genes can be simultaneously disrupted in a single editing event with high efficiency. Our approach offers an opportunity to explore the genetic interaction and molecular underpinning of gene clusters with redundant function.
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Affiliation(s)
- Longjun Pu
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Lars Nilsson
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Changchun Chen
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Jing Wang
- Department of Molecular Biology, Umeå University, Umeå, Sweden
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
- Wallenberg Centre for Molecular Medicine, Umeå University, Umeå, Sweden
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32
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Warnhoff K, Bhattacharya S, Snoozy J, Breen PC, Ruvkun G. Hypoxia-inducible factor induces cysteine dioxygenase and promotes cysteine homeostasis in Caenorhabditis elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.04.538701. [PMID: 37205365 PMCID: PMC10187278 DOI: 10.1101/2023.05.04.538701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Dedicated genetic pathways regulate cysteine homeostasis. For example, high levels of cysteine activate cysteine dioxygenase, a key enzyme in cysteine catabolism in most animal and many fungal species. The mechanism by which cysteine dioxygenase is regulated is largely unknown. In an unbiased genetic screen for mutations that activate cysteine dioxygenase (cdo-1) in the nematode C. elegans, we isolated loss-of-function mutations in rhy-1 and egl-9, which encode proteins that negatively regulate the stability or activity of the oxygen-sensing hypoxia inducible transcription factor (hif-1). EGL-9 and HIF-1 are core members of the conserved eukaryotic hypoxia response. However, we demonstrate that the mechanism of HIF-1-mediated induction of cdo-1 is largely independent of EGL-9 prolyl hydroxylase activity and the von Hippel-Lindau E3 ubiquitin ligase, the classical hypoxia signaling pathway components. We demonstrate that C. elegans cdo-1 is transcriptionally activated by high levels of cysteine and hif-1. hif-1-dependent activation of cdo-1 occurs downstream of an H2S-sensing pathway that includes rhy-1, cysl-1, and egl-9. cdo-1 transcription is primarily activated in the hypodermis where it is also sufficient to drive sulfur amino acid metabolism. Thus, the regulation of cdo-1 by hif-1 reveals a negative feedback loop that maintains cysteine homeostasis. High levels of cysteine stimulate the production of an H2S signal. H2S then acts through the rhy-1/cysl-1/egl-9 signaling pathway to increase HIF-1-mediated transcription of cdo-1, promoting degradation of cysteine via CDO-1.
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Affiliation(s)
- Kurt Warnhoff
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, SD 57104, USA
- Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD 57105 USA
| | - Sushila Bhattacharya
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, SD 57104, USA
| | - Jennifer Snoozy
- Pediatrics and Rare Diseases Group, Sanford Research, Sioux Falls, SD 57104, USA
| | - Peter C. Breen
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
| | - Gary Ruvkun
- Department of Molecular Biology, Massachusetts General Hospital, Boston, MA 02114, USA
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33
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Glomb O, Swaim G, Munoz LLancao P, Lovejoy C, Sutradhar S, Park J, Wu Y, Cason SE, Holzbaur ELF, Hammarlund M, Howard J, Ferguson SM, Gramlich MW, Yogev S. A kinesin-1 adaptor complex controls bimodal slow axonal transport of spectrin in Caenorhabditis elegans. Dev Cell 2023; 58:1847-1863.e12. [PMID: 37751746 PMCID: PMC10574138 DOI: 10.1016/j.devcel.2023.08.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 08/18/2023] [Accepted: 08/30/2023] [Indexed: 09/28/2023]
Abstract
An actin-spectrin lattice, the membrane periodic skeleton (MPS), protects axons from breakage. MPS integrity relies on spectrin delivery via slow axonal transport, a process that remains poorly understood. We designed a probe to visualize endogenous spectrin dynamics at single-axon resolution in vivo. Surprisingly, spectrin transport is bimodal, comprising fast runs and movements that are 100-fold slower than previously reported. Modeling and genetic analysis suggest that the two rates are independent, yet both require kinesin-1 and the coiled-coil proteins UNC-76/FEZ1 and UNC-69/SCOC, which we identify as spectrin-kinesin adaptors. Knockdown of either protein led to disrupted spectrin motility and reduced distal MPS, and UNC-76 overexpression instructed excessive transport of spectrin. Artificially linking spectrin to kinesin-1 drove robust motility but inefficient MPS assembly, whereas impairing MPS assembly led to excessive spectrin transport, suggesting a balance between transport and assembly. These results provide insight into slow axonal transport and MPS integrity.
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Affiliation(s)
- Oliver Glomb
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA
| | - Grace Swaim
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA; Department of Cell Biology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Pablo Munoz LLancao
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Christopher Lovejoy
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06510, USA
| | - Sabyasachi Sutradhar
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA
| | - Junhyun Park
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA
| | - Youjun Wu
- Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA
| | - Sydney E Cason
- Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104, USA; Neuroscience Graduate Group, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Erika L F Holzbaur
- Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104, USA; Pennsylvania Muscle Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Marc Hammarlund
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA; Department of Genetics, Yale School of Medicine, New Haven, CT 06510, USA
| | - Jonathon Howard
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510, USA; Quantitative Biology Institute, Yale University, New Haven, CT 06510, USA
| | - Shawn M Ferguson
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06510, USA
| | | | - Shaul Yogev
- Department of Neuroscience, Yale School of Medicine, New Haven, CT 06510, USA.
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34
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Nasrallah MA, Peterson ND, Szumel ES, Liu P, Page AL, Tse SY, Wani KA, Tocheny CE, Pukkila-Worley R. Transcriptional suppression of sphingolipid catabolism controls pathogen resistance in C. elegans. PLoS Pathog 2023; 19:e1011730. [PMID: 37906605 PMCID: PMC10637724 DOI: 10.1371/journal.ppat.1011730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 11/10/2023] [Accepted: 10/01/2023] [Indexed: 11/02/2023] Open
Abstract
Sphingolipids are required for diverse biological functions and are degraded by specific catabolic enzymes. However, the mechanisms that regulate sphingolipid catabolism are not known. Here we characterize a transcriptional axis that regulates sphingolipid breakdown to control resistance against bacterial infection. From an RNAi screen for transcriptional regulators of pathogen resistance in the nematode C. elegans, we identified the nuclear hormone receptor nhr-66, a ligand-gated transcription factor homologous to human hepatocyte nuclear factor 4. Tandem chromatin immunoprecipitation-sequencing and RNA sequencing experiments revealed that NHR-66 is a transcriptional repressor, which directly targets sphingolipid catabolism genes. Transcriptional de-repression of two sphingolipid catabolic enzymes in nhr-66 loss-of-function mutants drives the breakdown of sphingolipids, which enhances host susceptibility to infection with the bacterial pathogen Pseudomonas aeruginosa. These data define transcriptional control of sphingolipid catabolism in the regulation of cellular sphingolipids, a process that is necessary for pathogen resistance.
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Affiliation(s)
- Mohamad A. Nasrallah
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Nicholas D. Peterson
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Elizabeth S. Szumel
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Pengpeng Liu
- Department of Molecular, Cell and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Amanda L. Page
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Samantha Y. Tse
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Khursheed A. Wani
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Claire E. Tocheny
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Read Pukkila-Worley
- Program in Innate Immunity, Division of Infectious Diseases and Immunology, Department of Medicine, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
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35
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Gibney TV, Favichia M, Latifi L, Medwig-Kinney TN, Matus DQ, McIntyre DC, Arrigo AB, Branham KR, Bubrig LT, Ghaddar A, Jiranek JA, Liu KE, Marcucci CG, Porter RJ, Pani AM. A simple method to dramatically increase C. elegans germline microinjection efficiency. Dev Biol 2023; 502:63-67. [PMID: 37433390 PMCID: PMC10559938 DOI: 10.1016/j.ydbio.2023.07.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 07/06/2023] [Accepted: 07/07/2023] [Indexed: 07/13/2023]
Abstract
Genome manipulation methods in C. elegans require microinjecting DNA or ribonucleoprotein complexes into the microscopic core of the gonadal syncytium. These microinjections are technically demanding and represent a key bottleneck for all genome engineering and transgenic approaches in C. elegans. While there have been steady improvements in the ease and efficiency of genetic methods for C. elegans genome manipulation, there have not been comparable advances in the physical process of microinjection. Here, we report a simple and inexpensive method for handling worms using a paintbrush during the injection process that nearly tripled average microinjection rates compared to traditional worm handling methods. We found that the paintbrush increased injection throughput by substantially increasing both injection speeds and post-injection survival rates. In addition to dramatically and universally increasing injection efficiency for experienced personnel, the paintbrush method also significantly improved the abilities of novice investigators to perform key steps in the microinjection process. We expect that this method will benefit the C. elegans community by increasing the speed at which new strains can be generated and will also make microinjection-based approaches less challenging and more accessible to personnel and labs without extensive experience.
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Affiliation(s)
- Theresa V Gibney
- Department of Biology, University of Virginia, Charlottesville, VA, USA.
| | - Michelle Favichia
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Laila Latifi
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | | | - David Q Matus
- Department of Biochemistry & Cell Biology, Stony Brook University, Stony Brook, NY, USA
| | - Daniel C McIntyre
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Angelo B Arrigo
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Kendall R Branham
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Louis T Bubrig
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Abbas Ghaddar
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Juliana A Jiranek
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Kendra E Liu
- Department of Cell Biology, University of Virginia, Charlottesville, VA, USA
| | - Charles G Marcucci
- Neuroscience Graduate Program, University of Virginia, Charlottesville, VA, USA
| | - Robert J Porter
- Department of Biology, University of Virginia, Charlottesville, VA, USA
| | - Ariel M Pani
- Department of Biology, University of Virginia, Charlottesville, VA, USA; Department of Cell Biology, University of Virginia, Charlottesville, VA, USA.
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36
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Price IF, Wagner JA, Pastore B, Hertz HL, Tang W. C. elegans germ granules sculpt both germline and somatic RNAome. Nat Commun 2023; 14:5965. [PMID: 37749091 PMCID: PMC10520050 DOI: 10.1038/s41467-023-41556-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Accepted: 09/08/2023] [Indexed: 09/27/2023] Open
Abstract
Germ granules are membrane-less organelles essential for small RNA biogenesis and germline development. Among the conserved properties of germ granules is their association with the nuclear membrane. Recent studies demonstrated that LOTUS domain proteins, EGGD-1 and EGGD-2 (also known as MIP-1 and MIP-2 respectively), promote the formation of perinuclear germ granules in C. elegans. This finding presents a unique opportunity to evaluate the significance of perinuclear localization of germ granules. Here we show that loss of eggd-1 causes the coalescence of germ granules and formation of abnormal cytoplasmic aggregates. Impairment of perinuclear granules affects certain germline classes of small RNAs including Piwi-interacting RNAs. Transcriptome profiling reveals overexpression of spermatogenic and cuticle-related genes in eggd-1 hermaphrodites. We further demonstrate that disruption of germ granules activates HLH-30-mediated transcriptional program in somatic tissues. Collectively, our findings underscore the essential role of EGGD-1 in germ granule organization and reveal an unexpected germ granule-to-soma communication.
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Affiliation(s)
- Ian F Price
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH, 43210, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, 43210, USA
| | - Jillian A Wagner
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH, 43210, USA
| | - Benjamin Pastore
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH, 43210, USA
- Ohio State Biochemistry Program, The Ohio State University, Columbus, OH, 43210, USA
| | - Hannah L Hertz
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA
- Center for RNA Biology, The Ohio State University, Columbus, OH, 43210, USA
| | - Wen Tang
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, 43210, USA.
- Center for RNA Biology, The Ohio State University, Columbus, OH, 43210, USA.
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37
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Tzeng CP, Shen K. Wnt signaling and contact-mediated repulsion shape sensory dendritic fields. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.14.557812. [PMID: 37781584 PMCID: PMC10540810 DOI: 10.1101/2023.09.14.557812] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
The complete and non-redundant coverage of sensory tissues by neighboring neurons enables effective detection of stimuli in the environment. How the neurites of adjacent neurons establish their boundaries to achieve this completeness in coverage remains incompletely understood. Here, we use distinct fluorescent reporters to study two neighboring sensory neurons with complex dendritic arbors, FLP and PVD, in C. elegans . We quantify the sizes of their dendritic fields, and identify CWN-2/Wnt and LIN-17/Frizzled as a ligand and receptor that regulate the relative dendritic field sizes of these two neurons. Loss of either cwn-2 or lin-17 results in complementary changes in the size of the dendritic fields of both neurons; the FLP arbor expands, while that of PVD shrinks. Using an endogenous knock-in mNeonGreen-CWN-2/Wnt, we find that CWN-2/Wnt is localized along the path of growing FLP dendrites. Dynamic imaging shows a significant braking of FLP dendrite growth upon CWN-2/Wnt contact. We find that LIN-17/Frizzled functions cell-autonomously in FLP to limit dendritic field size and propose that PVD fills the space left by FLP through contact-induced retraction. Our results reveal that interactions of dendrites with adjacent dendrites and with environmental cues both shape the boundaries of neighboring dendritic fields. Highlights ▫ Secreted Wnt CWN-2 and cell-autonomous activity of neuronal LIN-17/Frizzled receptors restrict FLP dendritic field sizes▫ Endogenously tagged CWN-2/Wnt is punctate and visible in the same plane of growing FLP dendrites▫ Growth of developing FLP dendrites is inhibited upon contact with extracellular CWN-2/Wnt and with PVD dendrites.
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38
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Wang H, Vant J, Wu Y, Sanchez R, Micou ML, Zhang A, Luczak V, Yu SB, Jabbo M, Yoon S, Abushawish AA, Ghassemian M, Griffis E, Hammarlund M, Singharoy A, Pekkurnaz G. Functional Organization of Glycolytic Metabolon on Mitochondria. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.26.554955. [PMID: 37662343 PMCID: PMC10473731 DOI: 10.1101/2023.08.26.554955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Glucose, the primary cellular energy source, is metabolized through glycolysis initiated by the rate-limiting enzyme Hexokinase (HK). In energy-demanding tissues like the brain, HK1 is the dominant isoform, primarily localized on mitochondria, crucial for efficient glycolysis-oxidative phosphorylation coupling and optimal energy generation. This study unveils a unique mechanism regulating HK1 activity, glycolysis, and the dynamics of mitochondrial coupling, mediated by the metabolic sensor enzyme O-GlcNAc transferase (OGT). OGT catalyzes reversible O-GlcNAcylation, a post-translational modification, influenced by glucose flux. Elevated OGT activity induces dynamic O-GlcNAcylation of HK1's regulatory domain, subsequently promoting the assembly of the glycolytic metabolon on the outer mitochondrial membrane. This modification enhances HK1's mitochondrial association, orchestrating glycolytic and mitochondrial ATP production. Mutations in HK1's O-GlcNAcylation site reduce ATP generation, affecting synaptic functions in neurons. The study uncovers a novel pathway that bridges neuronal metabolism and mitochondrial function via OGT and the formation of the glycolytic metabolon, offering new prospects for tackling metabolic and neurological disorders.
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39
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Zhang P, Medwig-Kinney TN, Goldstein B. Architecture of the cortical actomyosin network driving apical constriction in C. elegans. J Cell Biol 2023; 222:e202302102. [PMID: 37351566 PMCID: PMC10289891 DOI: 10.1083/jcb.202302102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 05/24/2023] [Accepted: 06/06/2023] [Indexed: 06/24/2023] Open
Abstract
Apical constriction is a cell shape change that drives key morphogenetic events during development, including gastrulation and neural tube formation. The forces driving apical constriction are primarily generated through the contraction of apicolateral and/or medioapical actomyosin networks. In the Drosophila ventral furrow, the medioapical actomyosin network has a sarcomere-like architecture, with radially polarized actin filaments and centrally enriched non-muscle myosin II and myosin activating kinase. To determine if this is a broadly conserved actin architecture driving apical constriction, we examined actomyosin architecture during C. elegans gastrulation, in which two endodermal precursor cells internalize from the surface of the embryo. Quantification of protein localization showed that neither the non-muscle myosin II NMY-2 nor the myosin-activating kinase MRCK-1 is enriched at the center of the apex. Further, visualization of barbed- and pointed-end capping proteins revealed that actin filaments do not exhibit radial polarization at the apex. Our results demonstrate that C. elegans endodermal precursor cells apically constrict using a mixed-polarity actin filament network and with myosin and a myosin activator distributed throughout the network. Taken together with observations made in other organisms, our results demonstrate that diverse actomyosin architectures are used in animal cells to accomplish apical constriction.
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Affiliation(s)
- Pu Zhang
- Biology Department, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | | | - Bob Goldstein
- Biology Department, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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40
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Torzone SK, Park AY, Breen PC, Cohen NR, Dowen RH. Opposing action of the FLR-2 glycoprotein hormone and DRL-1/FLR-4 MAP kinases balance p38-mediated growth and lipid homeostasis in C. elegans. PLoS Biol 2023; 21:e3002320. [PMID: 37773960 PMCID: PMC10566725 DOI: 10.1371/journal.pbio.3002320] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 10/11/2023] [Accepted: 09/02/2023] [Indexed: 10/01/2023] Open
Abstract
Animals integrate developmental and nutritional signals before committing crucial resources to growth and reproduction; however, the pathways that perceive and respond to these inputs remain poorly understood. Here, we demonstrate that DRL-1 and FLR-4, which share similarity with mammalian mitogen-activated protein kinases, maintain lipid homeostasis in the C. elegans intestine. DRL-1 and FLR-4 function in a protein complex at the plasma membrane to promote development, as mutations in drl-1 or flr-4 confer slow growth, small body size, and impaired lipid homeostasis. To identify factors that oppose DRL-1/FLR-4, we performed a forward genetic screen for suppressors of the drl-1 mutant phenotypes and identified mutations in flr-2 and fshr-1, which encode the orthologues of follicle stimulating hormone and its putative G protein-coupled receptor, respectively. In the absence of DRL-1/FLR-4, neuronal FLR-2 acts through intestinal FSHR-1 and protein kinase A signaling to restrict growth. Furthermore, we show that opposing signaling through DRL-1 and FLR-2 coordinates TIR-1 oligomerization, which modulates downstream p38/PMK-1 activity, lipid homeostasis, and development. Finally, we identify a surprising noncanonical role for the developmental transcription factor PHA-4/FOXA in the intestine where it restricts growth in response to impaired DRL-1 signaling. Our work uncovers a complex multi-tissue signaling network that converges on p38 signaling to maintain homeostasis during development.
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Affiliation(s)
- Sarah K. Torzone
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Aaron Y. Park
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Peter C. Breen
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Natalie R. Cohen
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Robert H. Dowen
- Integrative Program for Biological and Genome Sciences, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Biology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
- Department of Cell Biology and Physiology, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
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41
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Eroglu M, Yu B, Derry WB. Efficient CRISPR/Cas9 mediated large insertions using long single-stranded oligonucleotide donors in C. elegans. FEBS J 2023; 290:4429-4439. [PMID: 37254814 DOI: 10.1111/febs.16876] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 04/05/2023] [Accepted: 05/25/2023] [Indexed: 06/01/2023]
Abstract
Highly efficient generation of deletions, substitutions, and small insertions (up to ~ 150 bp) into the Caenorhabditis elegans genome by CRISPR/Cas9 has been facilitated by the use of single-stranded oligonucleotide donors as repair templates. However, insertion of larger sequences such as fluorescent markers and other functional domains remains challenging due to uncertainty of optimal performance between single-stranded or double-stranded repair templates and labor-intensive as well as inefficient protocols for their preparations. Here, we simplify the generation of long ssDNA as donors in CRISPR/Cas9. High yields of ssDNA can be rapidly generated using a standard PCR followed by a single enzymatic digest with lambda exonuclease. Comparison of long ssDNA donors obtained using this method to dsDNA demonstrates orders of magnitude increased insertion frequency for ssDNA donors. This can be leveraged to simultaneously generate multiple large insertions as well as successful edits without the use of selection or co-conversion (co-CRISPR) markers when necessary. Our approach complements the CRISPR/Cas9 toolkit for C. elegans to enable highly efficient insertion of longer sequences with a simple, standardized, and labor-minimal protocol.
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Affiliation(s)
- Matthew Eroglu
- Developmental and Stem Cell Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Canada
- Department of Molecular Genetics, University of Toronto, Canada
| | - Bin Yu
- Developmental and Stem Cell Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Canada
| | - W Brent Derry
- Developmental and Stem Cell Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, Canada
- Department of Molecular Genetics, University of Toronto, Canada
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42
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Le E, McCarthy T, Honer M, Curtin CE, Fingerut J, Nelson MD. The neuropeptide receptor npr-38 regulates avoidance and stress-induced sleep in Caenorhabditis elegans. Curr Biol 2023; 33:3155-3168.e9. [PMID: 37419114 DOI: 10.1016/j.cub.2023.06.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Revised: 05/19/2023] [Accepted: 06/14/2023] [Indexed: 07/09/2023]
Abstract
Although essential and conserved, sleep is not without its challenges that must be overcome; most notably, it renders animals vulnerable to threats in the environment. Infection and injury increase sleep demand, which dampens sensory responsiveness to stimuli, including those responsible for the initial insult. Stress-induced sleep in Caenorhabditis elegans occurs in response to cellular damage following noxious exposures the animals attempted to avoid. Here, we describe a G-protein-coupled receptor (GPCR) encoded by npr-38, which is required for stress-related responses including avoidance, sleep, and arousal. Overexpression of npr-38 shortens the avoidance phase and causes animals to initiate movement quiescence and arouse early. npr-38 functions in the ADL sensory neurons, which express neuropeptides encoded by nlp-50, also required for movement quiescence. npr-38 regulates arousal by acting on the DVA and RIS interneurons. Our work demonstrates that this single GPCR regulates multiple aspects of the stress response by functioning in sensory and sleep interneurons.
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Affiliation(s)
- Emily Le
- Department of Biology, Saint Joseph's University, Philadelphia, PA 19131, USA
| | - Teagan McCarthy
- Department of Biology, Saint Joseph's University, Philadelphia, PA 19131, USA
| | - Madison Honer
- Department of Biology, Saint Joseph's University, Philadelphia, PA 19131, USA
| | - Caroline E Curtin
- Department of Biology, Saint Joseph's University, Philadelphia, PA 19131, USA
| | - Jonathan Fingerut
- Department of Biology, Saint Joseph's University, Philadelphia, PA 19131, USA
| | - Matthew D Nelson
- Department of Biology, Saint Joseph's University, Philadelphia, PA 19131, USA.
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43
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Wu Y, Ding C, Weinreb A, Manning L, Swaim G, Yogev S, Colón-Ramos DA, Hammarlund M. Polarized localization of kinesin-1 and RIC-7 drives axonal mitochondria anterograde transport. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.12.548706. [PMID: 37502914 PMCID: PMC10369933 DOI: 10.1101/2023.07.12.548706] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Mitochondria transport is crucial for mitochondria distribution in axons and is mediated by kinesin-1-based anterograde and dynein-based retrograde motor complexes. While Miro and Milton/TRAK were identified as key adaptors between mitochondria and kinesin-1, recent studies suggest the presence of additional mechanisms. In C. elegans, ric-7 is the only single gene described so far, other than kinesin-1, that is absolutely required for axonal mitochondria localization. Using CRISPR engineering in C. elegans, we find that Miro is important but is not essential for anterograde traffic, whereas it is required for retrograde traffic. Both the endogenous RIC-7 and kinesin-1 act at the leading end to transport mitochondria anterogradely. RIC-7 recruitment to mitochondria requires its N-terminal domain and partially relies on MIRO-1, whereas RIC-7 accumulation at the leading end depends on its disordered region, kinesin-1 and metaxin2. We conclude that polarized transport complexes containing kinesin-1 and RIC-7 form at the leading edge of mitochondria, and that these complexes are required for anterograde axonal transport.
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Affiliation(s)
- Youjun Wu
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06536, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Chen Ding
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Alexis Weinreb
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06536, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Laura Manning
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Grace Swaim
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Shaul Yogev
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Daniel A Colón-Ramos
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06536, USA
| | - Marc Hammarlund
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06536, USA
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06536, USA
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44
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Nonet ML. Rapid generation of Caenorhabditis elegans single-copy transgenes combining recombination-mediated cassette exchange and drug selection. Genetics 2023; 224:iyad072. [PMID: 37079426 PMCID: PMC10324946 DOI: 10.1093/genetics/iyad072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/04/2023] [Accepted: 04/11/2023] [Indexed: 04/21/2023] Open
Abstract
I outline a streamlined method to insert large, single-copy transgenes into the Caenorhabditis elegans genome using recombination-mediated cassette exchange (RMCE) that relies solely on drug selection yielding a homozygous fluorescent protein (FP) marked transgene in 3 generations (8 days) at high efficiency (>1 insertion per 2 injected P0 animals). Landing sites for this approach are available on four chromosomes in several configurations which yield lines marked in distinct cell types. An array of vectors permit creating transgenes using a variety of selection methods (HygR, NeoR, PuroR, and unc-119) that yield lines expressing different colored FPs (BFP, GFP, mNG, and Scarlet). Although these transgenes retain a plasmid backbone and a selection marker, the inclusion of these sequences typically does not alter the expression of several cell-specific promoters tested. However, in certain orientations, promoters exhibit crosstalk with adjacent transcription units. In cases where crosstalk is problematic, the loxP-flanked fluorescent marker, plasmid backbone, and hygR gene can be excised by crossing through germline Cre expressing lines also created using this technique. Finally, genetic and molecular reagents designed to facilitate customization of both targeting vectors and landing sites are also described. Together, the rapid RMCE toolbox provides a platform for developing further innovative uses of RMCE to create complex genetically engineered tools.
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Affiliation(s)
- Michael L Nonet
- Department of Neuroscience, Washington University Medical School, St. Louis, MO 63110, USA
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45
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Widen SA, Bes IC, Koreshova A, Pliota P, Krogull D, Burga A. Virus-like transposons cross the species barrier and drive the evolution of genetic incompatibilities. Science 2023; 380:eade0705. [PMID: 37384706 DOI: 10.1126/science.ade0705] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 05/17/2023] [Indexed: 07/01/2023]
Abstract
Horizontal gene transfer, the movement of genetic material between species, has been reported across all major eukaryotic lineages. However, the underlying mechanisms of transfer and their impact on genome evolution are still poorly understood. While studying the evolutionary origin of a selfish element in the nematode Caenorhabditis briggsae, we discovered that Mavericks, ancient virus-like transposons related to giant viruses and virophages, are one of the long-sought vectors of horizontal gene transfer. We found that Mavericks gained a novel herpesvirus-like fusogen in nematodes, leading to the widespread exchange of cargo genes between extremely divergent species, bypassing sexual and genetic barriers spanning hundreds of millions of years. Our results show how the union between viruses and transposons causes horizontal gene transfer and ultimately genetic incompatibilities in natural populations.
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Affiliation(s)
- Sonya A Widen
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Israel Campo Bes
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Alevtina Koreshova
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, A-1030 Vienna, Austria
| | - Pinelopi Pliota
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
| | - Daniel Krogull
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
- Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna, A-1030 Vienna, Austria
| | - Alejandro Burga
- Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna BioCenter (VBC), 1030 Vienna, Austria
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46
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McDonald NA, Tao L, Dong MQ, Shen K. SAD-1 kinase controls presynaptic phase separation by relieving SYD-2/Liprin-α autoinhibition. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.12.544643. [PMID: 37398223 PMCID: PMC10312667 DOI: 10.1101/2023.06.12.544643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Neuronal development orchestrates the formation of an enormous number of synapses that connect the nervous system. In developing presynapses, the core active zone structure has been found to assemble through a liquid-liquid phase separation. Here, we find that the phase separation of SYD-2/Liprin-α, a key active zone scaffold, is controlled by phosphorylation. Using phosphoproteomics, we identify the SAD-1 kinase to phosphorylate SYD-2 and a number of other substrates. Presynaptic assembly is impaired in sad-1 mutants and increased by overactivation of SAD-1. We determine SAD-1 phosphorylation of SYD-2 at three sites is critical to activate its phase separation. Mechanistically, phosphorylation relieves a binding interaction between two folded SYD-2 domains that inhibits phase separation by an intrinsically disordered region. We find synaptic cell adhesion molecules localize SAD-1 to nascent synapses upstream of active zone formation. We conclude that SAD-1 phosphorylates SYD-2 at developing synapses, enabling its phase separation and active zone assembly.
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Affiliation(s)
| | - Li Tao
- Department of Biology, Stanford University, Stanford, CA, USA
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing, China
| | - Kang Shen
- Department of Biology, Stanford University, Stanford, CA, USA
- Howard Hughes Medical Institute, Stanford University, Stanford, CA, USA
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47
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Johnson LC, Vo AA, Clancy JC, Myles KM, Pooranachithra M, Aguilera J, Levenson MT, Wohlenberg C, Rechtsteiner A, Ragle JM, Chisholm AD, Ward JD. NHR-23 activity is necessary for C. elegans developmental progression and apical extracellular matrix structure and function. Development 2023; 150:dev201085. [PMID: 37129010 PMCID: PMC10233720 DOI: 10.1242/dev.201085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 04/11/2023] [Indexed: 05/03/2023]
Abstract
Nematode molting is a remarkable process where animals must repeatedly build a new apical extracellular matrix (aECM) beneath a previously built aECM that is subsequently shed. The nuclear hormone receptor NHR-23 (also known as NR1F1) is an important regulator of C. elegans molting. NHR-23 expression oscillates in the epidermal epithelium, and soma-specific NHR-23 depletion causes severe developmental delay and death. Tissue-specific RNAi suggests that nhr-23 acts primarily in seam and hypodermal cells. NHR-23 coordinates the expression of factors involved in molting, lipid transport/metabolism and remodeling of the aECM. NHR-23 depletion causes dampened expression of a nas-37 promoter reporter and a loss of reporter oscillation. The cuticle collagen ROL-6 and zona pellucida protein NOAH-1 display aberrant annular localization and severe disorganization over the seam cells after NHR-23 depletion, while the expression of the adult-specific cuticle collagen BLI-1 is diminished and frequently found in patches. Consistent with these localization defects, the cuticle barrier is severely compromised when NHR-23 is depleted. Together, this work provides insight into how NHR-23 acts in the seam and hypodermal cells to coordinate aECM regeneration during development.
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Affiliation(s)
- Londen C. Johnson
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - An A. Vo
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - John C. Clancy
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Krista M. Myles
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Murugesan Pooranachithra
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Joseph Aguilera
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Max T. Levenson
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Chloe Wohlenberg
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Andreas Rechtsteiner
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - James Matthew Ragle
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
| | - Andrew D. Chisholm
- Department of Cell and Developmental Biology, School of Biological Sciences, University of California San Diego, La Jolla, CA 92093, USA
| | - Jordan D. Ward
- Department of Molecular, Cell, and Developmental Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA
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48
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Morton EA, Hall AN, Cuperus JT, Queitsch C. Substantial rDNA copy number reductions alter timing of development and produce variable tissue-specific phenotypes in C. elegans. Genetics 2023; 224:iyad039. [PMID: 36919976 PMCID: PMC10474940 DOI: 10.1093/genetics/iyad039] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 03/01/2023] [Accepted: 03/02/2023] [Indexed: 03/16/2023] Open
Abstract
The genes that encode ribosomal RNAs are present in several hundred copies in most eukaryotes. These vast arrays of repetitive ribosomal DNA (rDNA) have been implicated not just in ribosome biogenesis, but also aging, cancer, genome stability, and global gene expression. rDNA copy number is highly variable among and within species; this variability is thought to associate with traits relevant to human health and disease. Here we investigate the phenotypic consequences of multicellular life at the lower bounds of rDNA copy number. We use the model Caenorhabditis elegans, which has previously been found to complete embryogenesis using only maternally provided ribosomes. We find that individuals with rDNA copy number reduced to ∼5% of wild type are capable of further development with variable penetrance. Such individuals are sterile and exhibit severe morphological defects, particularly in post-embryonically dividing tissues such as germline and vulva. Developmental completion and fertility are supported by an rDNA copy number ∼10% of wild type, with substantially delayed development. Worms with rDNA copy number reduced to ∼33% of wild type display a subtle developmental timing defect that was absent in worms with higher copy numbers. Our results support the hypothesis that rDNA requirements vary across tissues and indicate that the minimum rDNA copy number for fertile adulthood is substantially less than the lowest naturally observed total copy number. The phenotype of individuals with severely reduced rDNA copy number is highly variable in penetrance and presentation, highlighting the need for continued investigation into the biological consequences of rDNA copy number variation.
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Affiliation(s)
| | - Ashley N Hall
- Wisconsin Energy Institute, University of Wisconsin-Madison, Madison, WI 53726, USA
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA 98195, USA
| | - Josh T Cuperus
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
| | - Christine Queitsch
- Department of Genome Sciences, University of Washington, Seattle, WA 98195, USA
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49
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Urso SJ, Sathaseevan A, Brent Derry W, Lamitina T. Regulation of the hypertonic stress response by the 3' mRNA cleavage and polyadenylation complex. Genetics 2023; 224:iyad051. [PMID: 36972377 PMCID: PMC10490458 DOI: 10.1093/genetics/iyad051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/10/2023] [Accepted: 03/10/2023] [Indexed: 03/29/2023] Open
Abstract
Maintenance of osmotic homeostasis is one of the most aggressively defended homeostatic set points in physiology. One major mechanism of osmotic homeostasis involves the upregulation of proteins that catalyze the accumulation of solutes called organic osmolytes. To better understand how osmolyte accumulation proteins are regulated, we conducted a forward genetic screen in Caenorhabditis elegans for mutants with no induction of osmolyte biosynthesis gene expression (Nio mutants). The nio-3 mutant encoded a missense mutation in cpf-2/CstF64, while the nio-7 mutant encoded a missense mutation in symk-1/Symplekin. Both cpf-2 and symk-1 are nuclear components of the highly conserved 3' mRNA cleavage and polyadenylation complex. cpf-2 and symk-1 block the hypertonic induction of gpdh-1 and other osmotically induced mRNAs, suggesting they act at the transcriptional level. We generated a functional auxin-inducible degron (AID) allele for symk-1 and found that acute, post-developmental degradation in the intestine and hypodermis was sufficient to cause the Nio phenotype. symk-1 and cpf-2 exhibit genetic interactions that strongly suggest they function through alterations in 3' mRNA cleavage and/or alternative polyadenylation. Consistent with this hypothesis, we find that inhibition of several other components of the mRNA cleavage complex also cause a Nio phenotype. cpf-2 and symk-1 specifically affect the osmotic stress response since heat shock-induced upregulation of a hsp-16.2::GFP reporter is normal in these mutants. Our data suggest a model in which alternative polyadenylation of 1 or more mRNAs is essential to regulate the hypertonic stress response.
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Affiliation(s)
- Sarel J Urso
- Graduate Program in Cell Biology and Molecular Physiology, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Anson Sathaseevan
- Developmental and Stem Cell Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - W Brent Derry
- Developmental and Stem Cell Biology Program, Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Todd Lamitina
- Graduate Program in Cell Biology and Molecular Physiology, University of Pittsburgh Medical Center, Pittsburgh, PA 15261, USA
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
- Division of Child Neurology, Department of Pediatrics, Children's Hospital of Pittsburgh, University of Pittsburgh Medical Center, Pittsburgh, PA 15224, USA
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50
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Clancy JC, Vo AA, Myles KM, Levenson MT, Ragle JM, Ward JD. Experimental considerations for study of C. elegans lysosomal proteins. G3 (BETHESDA, MD.) 2023; 13:jkad032. [PMID: 36748711 PMCID: PMC10085801 DOI: 10.1093/g3journal/jkad032] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 06/20/2022] [Accepted: 01/27/2023] [Indexed: 02/08/2023]
Abstract
Lysosomes are an important organelle required for the degradation of a range of cellular components. Lysosome function is critical for development and homeostasis as dysfunction can lead to inherited genetic disorders, cancer, and neurodegenerative and metabolic diseases. The acidic and protease-rich environment of lysosomes poses experimental challenges. Many fluorescent proteins are quenched or degraded, while specific red fluorescent proteins can be cleaved from translational fusion partners and accumulate. While studying MLT-11, a Caenorhabditis elegans molting factor that localizes to lysosomes and the cuticle, we sought to optimize several experimental parameters. We found that, in contrast to mNeonGreen fusions, mScarlet fusions to MLT-11 missed cuticular and rectal epithelial localization. Rapid sample lysis and denaturation were critical for preventing MLT-11 fragmentation while preparing lysates for western blots. Using a model lysosomal substrate (NUC-1), we found that rigid polyproline linkers and truncated mCherry constructs do not prevent cleavage of mCherry from NUC-1. We provide evidence that extended localization in lysosomal environments prevents the detection of FLAG epitopes in western blots. Finally, we optimize an acid-tolerant green fluorescent protein (Gamillus) for use in C. elegans. These experiments provide important experimental considerations and new reagents for the study of C. elegans lysosomal proteins.
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Affiliation(s)
- John C Clancy
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - An A Vo
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Krista M Myles
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Max T Levenson
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - James Matthew Ragle
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
| | - Jordan D Ward
- Department of Molecular, Cell, and Developmental Biology, University of California-Santa Cruz, Santa Cruz, CA 95064, USA
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