1
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Peralta J, DuPriest B, Orozco D, Pacheco JR, Martins L, Soriano RA, Wong A, Wong R, Grillo-Hill B. Drosophila Nhe2 overexpression induces autophagic cell death. Mol Biol Cell 2024; 35:br13. [PMID: 38696256 PMCID: PMC11244158 DOI: 10.1091/mbc.e24-02-0058] [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: 02/06/2024] [Revised: 04/19/2024] [Accepted: 04/24/2024] [Indexed: 05/04/2024] Open
Abstract
Autophagy is a conserved catabolic process where double membrane-bound structures form around macromolecules or organelles targeted for degradation. Autophagosomes fuse with lysosomes to facilitate degradation and macromolecule recycling for homeostasis or growth in a cell autonomous manner. In cancer cells, autophagy is often up-regulated and helps cancer cells survive nutrient deprivation and stressful growth conditions. Here, we propose that the increased intracellular pH (pHi) common to cancer cells is sufficient to induce autophagic cell death. We previously developed tools to increase pHi in the Drosophila eye via overexpression of DNhe2, resulting in aberrant patterning and reduced tissue size. We examined fly eyes at earlier stages of development and found fewer interommatidial cells. We next tested whether this decrease in cell number was due to increased cell death. We found that the DNhe2-induced cell death was caspase independent, which is inconsistent with apoptosis. However, this cell death required autophagy genes, which supports autophagy as the mode of cell death. We also found that expression of molecular markers supports increased autophagy. Together, our findings suggest new roles for ion transport proteins in regulating conserved, critical developmental processes and provide evidence for new paradigms in growth control.
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Affiliation(s)
- Jobelle Peralta
- Department of Biological Sciences, San José State University, San José, CA 95112
| | - Blake DuPriest
- Department of Biological Sciences, San José State University, San José, CA 95112
| | - Daniel Orozco
- Department of Biological Sciences, San José State University, San José, CA 95112
| | - Juan Reyna Pacheco
- Department of Biological Sciences, San José State University, San José, CA 95112
| | - Laura Martins
- Department of Biological Sciences, San José State University, San José, CA 95112
| | - Rachel Ann Soriano
- Department of Biological Sciences, San José State University, San José, CA 95112
| | - Alan Wong
- Department of Biological Sciences, San José State University, San José, CA 95112
| | - Ramy Wong
- Department of Biological Sciences, San José State University, San José, CA 95112
| | - Bree Grillo-Hill
- Department of Biological Sciences, San José State University, San José, CA 95112
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2
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Eisenreichova A, Humpolickova J, Różycki B, Boura E, Koukalova A. Effects of biophysical membrane properties on recognition of phosphatidylserine, or phosphatidylinositol 4-phosphate by lipid biosensors LactC2, or P4M. Biochimie 2023; 215:42-49. [PMID: 37683994 DOI: 10.1016/j.biochi.2023.09.003] [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: 04/28/2023] [Revised: 08/25/2023] [Accepted: 09/04/2023] [Indexed: 09/10/2023]
Abstract
Lipid biosensors are molecular tools used both in vivo and in vitro applications, capable of selectively detecting specific types of lipids in biological membranes. However, despite their extensive use, there is a lack of systematic characterization of their binding properties in various membrane conditions. The purpose of this study was to investigate the impact of membrane properties, such as fluidity and membrane charge, on the sensitivity of two lipid biosensors, LactC2 and P4M, to their target lipids, phosphatidylserine (PS) or phosphatidylinositol 4-phosphate (PI4P), respectively. Dual-color fluorescence cross-correlation spectroscopy, employed in this study, provided a useful technique to investigate interactions of these recombinant fluorescent biosensors with liposomes of varying compositions. The results of the study demonstrate that the binding of the LactC2 biosensor to low levels of PS in the membrane is highly supported by the presence of anionic lipids or membrane fluidity. However, at high PS levels, the presence of anionic lipids does not further enhance binding of LactC2. In contrast, neither membrane charge, nor membrane fluidity significantly affect the binding affinity of P4M to PI4P. These findings provide valuable insights into the role of membrane properties on the binding properties of lipid biosensors.
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Affiliation(s)
- Andrea Eisenreichova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic
| | - Jana Humpolickova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic
| | - Bartosz Różycki
- Institute of Physics, Polish Academy of Sciences, Warsaw, Poland
| | - Evzen Boura
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic
| | - Alena Koukalova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague 6, Czech Republic.
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3
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Liu Y, Reyes E, Castillo-Azofeifa D, Klein OD, Nystul T, Barber DL. Intracellular pH dynamics regulates intestinal stem cell lineage specification. Nat Commun 2023; 14:3745. [PMID: 37353491 PMCID: PMC10290085 DOI: 10.1038/s41467-023-39312-9] [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: 09/15/2022] [Accepted: 06/06/2023] [Indexed: 06/25/2023] Open
Abstract
Intracellular pH dynamics is increasingly recognized to regulate myriad cell behaviors. We report a finding that intracellular pH dynamics also regulates adult stem cell lineage specification. We identify an intracellular pH gradient in mouse small intestinal crypts, lowest in crypt stem cells and increasing along the crypt column. Disrupting this gradient by inhibiting H+ efflux by Na+/H+ exchanger 1 abolishes crypt budding and blocks differentiation of Paneth cells, which are rescued with exogenous WNT. Using single-cell RNA sequencing and lineage tracing we demonstrate that intracellular pH dynamics acts downstream of ATOH1, with increased pH promoting differentiation toward the secretory lineage. Our findings indicate that an increase in pH is required for the lineage specification that contributes to crypt maintenance, establishing a role for intracellular pH dynamics in cell fate decisions within an adult stem cell lineage.
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Affiliation(s)
- Yi Liu
- Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Efren Reyes
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California San Francisco, San Francisco, CA, 94143, USA
| | - David Castillo-Azofeifa
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California San Francisco, San Francisco, CA, 94143, USA
- Immunology Discovery, Genentech, Inc., South San Francisco, CA, 94080, USA
| | - Ophir D Klein
- Program in Craniofacial Biology and Department of Orofacial Sciences, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Todd Nystul
- Departments of Anatomy, University of California San Francisco, San Francisco, CA, 94143, USA.
| | - Diane L Barber
- Department of Cell and Tissue Biology, University of California San Francisco, San Francisco, CA, 94143, USA.
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4
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Slika H, Mansour H, Nasser SA, Shaito A, Kobeissy F, Orekhov AN, Pintus G, Eid AH. Epac as a tractable therapeutic target. Eur J Pharmacol 2023; 945:175645. [PMID: 36894048 DOI: 10.1016/j.ejphar.2023.175645] [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: 08/21/2022] [Revised: 02/26/2023] [Accepted: 03/06/2023] [Indexed: 03/09/2023]
Abstract
In 1957, cyclic adenosine monophosphate (cAMP) was identified as the first secondary messenger, and the first signaling cascade discovered was the cAMP-protein kinase A (PKA) pathway. Since then, cAMP has received increasing attention given its multitude of actions. Not long ago, a new cAMP effector named exchange protein directly activated by cAMP (Epac) emerged as a critical mediator of cAMP's actions. Epac mediates a plethora of pathophysiologic processes and contributes to the pathogenesis of several diseases such as cancer, cardiovascular disease, diabetes, lung fibrosis, neurological disorders, and others. These findings strongly underscore the potential of Epac as a tractable therapeutic target. In this context, Epac modulators seem to possess unique characteristics and advantages and hold the promise of providing more efficacious treatments for a wide array of diseases. This paper provides an in-depth dissection and analysis of Epac structure, distribution, subcellular compartmentalization, and signaling mechanisms. We elaborate on how these characteristics can be utilized to design specific, efficient, and safe Epac agonists and antagonists that can be incorporated into future pharmacotherapeutics. In addition, we provide a detailed portfolio for specific Epac modulators highlighting their discovery, advantages, potential concerns, and utilization in the context of clinical disease entities.
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Affiliation(s)
- Hasan Slika
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, P.O. Box 11-0236, Lebanon.
| | - Hadi Mansour
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, P.O. Box 11-0236, Lebanon.
| | | | - Abdullah Shaito
- Biomedical Research Center, Qatar University, Doha, P.O. Box: 2713, Qatar.
| | - Firas Kobeissy
- Department of Neurobiology and Neuroscience, Morehouse School of Medicine, Atlanta, Georgia, USA.
| | - Alexander N Orekhov
- Laboratory of Cellular and Molecular Pathology of Cardiovascular System, Institute of Human Morphology, 3 Tsyurupa Street, Moscow, 117418, Russia; Laboratory of Angiopathology, Institute of General Pathology and Pathophysiology, 8 Baltiiskaya Street, Moscow, 125315, Russia; Institute for Atherosclerosis Research, Skolkovo Innovative Center, Osennyaya Street 4-1-207, Moscow, 121609, Russia.
| | - Gianfranco Pintus
- Department of Biomedical Sciences, University of Sassari, 07100, Sassari, Italy.
| | - Ali H Eid
- Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, P.O. Box 2713, Qatar.
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5
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Bowin CF, Kozielewicz P, Grätz L, Kowalski-Jahn M, Schihada H, Schulte G. WNT stimulation induces dynamic conformational changes in the Frizzled-Dishevelled interaction. Sci Signal 2023; 16:eabo4974. [PMID: 37014927 DOI: 10.1126/scisignal.abo4974] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/06/2023]
Abstract
Frizzleds (FZDs) are G protein-coupled receptors (GPCRs) that bind to WNT family ligands. FZDs signal through multiple effector proteins, including Dishevelled (DVL), which acts as a hub for several downstream signaling pathways. To understand how WNT binding to FZD stimulates intracellular signaling and influences downstream pathway selectivity, we investigated the dynamic changes in the FZD5-DVL2 interaction elicited by WNT-3A and WNT-5A. Ligand-induced changes in bioluminescence resonance energy transfer (BRET) between FZD5 and DVL2 or the isolated FZD-binding DEP domain of DVL2 revealed a composite response consisting of both DVL2 recruitment and conformational dynamics in the FZD5-DVL2 complex. The combination of different BRET paradigms enabled us to identify ligand-dependent conformational dynamics in the FZD5-DVL2 complex and distinguish them from ligand-induced recruitment of DVL2 or DEP to FZD5. The observed agonist-induced conformational changes at the receptor-transducer interface suggest that extracellular agonist and intracellular transducers cooperate through transmembrane allosteric interaction with FZDs in a ternary complex reminiscent of that of classical GPCRs.
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Affiliation(s)
- Carl-Fredrik Bowin
- Department of Physiology and Pharmacology, Section of Receptor Biology and Signaling, Karolinska Institutet, Stockholm, Sweden
| | - Pawel Kozielewicz
- Department of Physiology and Pharmacology, Section of Receptor Biology and Signaling, Karolinska Institutet, Stockholm, Sweden
| | - Lukas Grätz
- Department of Physiology and Pharmacology, Section of Receptor Biology and Signaling, Karolinska Institutet, Stockholm, Sweden
| | - Maria Kowalski-Jahn
- Department of Physiology and Pharmacology, Section of Receptor Biology and Signaling, Karolinska Institutet, Stockholm, Sweden
| | - Hannes Schihada
- Department of Physiology and Pharmacology, Section of Receptor Biology and Signaling, Karolinska Institutet, Stockholm, Sweden
| | - Gunnar Schulte
- Department of Physiology and Pharmacology, Section of Receptor Biology and Signaling, Karolinska Institutet, Stockholm, Sweden
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6
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Fonseca Ó, Gomes MS, Amorim MA, Gomes AC. Cystic Fibrosis Bone Disease: The Interplay between CFTR Dysfunction and Chronic Inflammation. Biomolecules 2023; 13:biom13030425. [PMID: 36979360 PMCID: PMC10046889 DOI: 10.3390/biom13030425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/19/2023] [Accepted: 02/22/2023] [Indexed: 03/30/2023] Open
Abstract
Cystic fibrosis is a monogenic disease with a multisystemic phenotype, ranging from predisposition to chronic lung infection and inflammation to reduced bone mass. The exact mechanisms unbalancing the maintenance of an optimal bone mass in cystic fibrosis patients remain unknown. Multiple factors may contribute to severe bone mass reduction that, in turn, have devastating consequences in the patients' quality of life and longevity. Here, we will review the existing evidence linking the CFTR dysfunction and cell-intrinsic bone defects. Additionally, we will also address how the proinflammatory environment due to CFTR dysfunction in immune cells and chronic infection impairs the maintenance of an adequate bone mass in CF patients.
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Affiliation(s)
- Óscar Fonseca
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
| | - Maria Salomé Gomes
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- ICBAS-Instuto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, 4030-313 Porto, Portugal
| | | | - Ana Cordeiro Gomes
- i3S-Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, 4200-135 Porto, Portugal
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7
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Yan P, Ke B, Fang X. Ion channels as a therapeutic target for renal fibrosis. Front Physiol 2022; 13:1019028. [PMID: 36277193 PMCID: PMC9581181 DOI: 10.3389/fphys.2022.1019028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
Renal ion channel transport and electrolyte disturbances play an important role in the process of functional impairment and fibrosis in the kidney. It is well known that there are limited effective drugs for the treatment of renal fibrosis, and since a large number of ion channels are involved in the renal fibrosis process, understanding the mechanisms of ion channel transport and the complex network of signaling cascades between them is essential to identify potential therapeutic approaches to slow down renal fibrosis. This review summarizes the current work of ion channels in renal fibrosis. We pay close attention to the effect of cystic fibrosis transmembrane conductance regulator (CFTR), transmembrane Member 16A (TMEM16A) and other Cl− channel mediated signaling pathways and ion concentrations on fibrosis, as well as the various complex mechanisms for the action of Ca2+ handling channels including Ca2+-release-activated Ca2+ channel (CRAC), purinergic receptor, and transient receptor potential (TRP) channels. Furthermore, we also focus on the contribution of Na+ transport such as epithelial sodium channel (ENaC), Na+, K+-ATPase, Na+-H+ exchangers, and K+ channels like Ca2+-activated K+ channels, voltage-dependent K+ channel, ATP-sensitive K+ channels on renal fibrosis. Proposed potential therapeutic approaches through further dissection of these mechanisms may provide new therapeutic opportunities to reduce the burden of chronic kidney disease.
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8
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Falginella FL, Kravec M, Drabinová M, Paclíková P, Bryja V, Vácha R. Binding of DEP domain to phospholipid membranes: More than just electrostatics. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183983. [PMID: 35750206 DOI: 10.1016/j.bbamem.2022.183983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 05/06/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Over the past decades an extensive effort has been made to provide a more comprehensive understanding of Wnt signaling, yet many regulatory and structural aspects remain elusive. Among these, the ability of Dishevelled (DVL) protein to relocalize at the plasma membrane is a crucial step in the activation of all Wnt pathways. The membrane binding of DVL was suggested to be mediated by the preferential interaction of its C-terminal DEP domain with phosphatidic acid (PA). However, due to the scarcity and fast turnover of PA, we investigated the role on the membrane association of other more abundant phospholipids. The combined results from computational simulations and experimental measurements with various model phospholipid membranes, demonstrate that the membrane binding of DEP/DVL constructs is governed by the concerted action of generic electrostatics and finely-tuned intermolecular interactions with individual lipid species. In particular, while we confirmed the strong preference for PA lipid, we also observed a weak but non-negligible affinity for phosphatidylserine, the most abundant anionic phospholipid in the plasma membrane, and phosphatidylinositol 4,5-bisphosphate. The obtained molecular insight into DEP-membrane interaction helps to elucidate the relation between changes in the local membrane composition and the spatiotemporal localization of DVL and, possibly, other DEP-containing proteins.
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Affiliation(s)
- Francesco L Falginella
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Marek Kravec
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno 62500, Czech Republic
| | - Martina Drabinová
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic
| | - Petra Paclíková
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno 62500, Czech Republic
| | - Vítĕzslav Bryja
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno 62500, Czech Republic; Institute of Biophysics, Academy of Sciences of the Czech Republic, v.v.i., Brno 612 65, Czech Republic
| | - Robert Vácha
- CEITEC - Central European Institute of Technology, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; National Centre for Biomolecular Research, Faculty of Science, Masaryk University, Kamenice 5, 625 00 Brno, Czech Republic; Department of Condensed Matter Physics, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic.
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9
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Angers S. Frizzled does not get bent out of shape by Wnt. Sci Signal 2022; 15:eadd3535. [PMID: 35998230 DOI: 10.1126/scisignal.add3535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Ligands of the Wnt family activate the Frizzled-LRP5/6 receptor complex to initiate intracellular signaling. In this issue of Science Signaling, Mahoney et al. reveal a Wnt-stimulated positive feedback loop that involves local production of the lipid phosphatidylinositol(4,5)bisphosphate [PI(4,5)P2], which promotes Dishevelled recruitment and additional PI(4,5)P2 production, to facilitate LRP5/6 phosphorylation.
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Affiliation(s)
- Stephane Angers
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON M5S 3E1, Canada.,Department of Biochemistry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON M5S 1A8, Canada.,Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON M5S 3M2, Canada.
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10
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Mahoney JP, Bruguera ES, Vasishtha M, Killingsworth LB, Kyaw S, Weis WI. PI(4,5)P 2-stimulated positive feedback drives the recruitment of Dishevelled to Frizzled in Wnt-β-catenin signaling. Sci Signal 2022; 15:eabo2820. [PMID: 35998232 PMCID: PMC9528458 DOI: 10.1126/scisignal.abo2820] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In the Wnt-β-catenin pathway, Wnt binding to Frizzled (Fzd) and LRP5 or LRP6 (LRP5/6) co-receptors inhibits the degradation of the transcriptional coactivator β-catenin by recruiting the cytosolic effector Dishevelled (Dvl). Polymerization of Dvl at the plasma membrane recruits the β-catenin destruction complex, enabling the phosphorylation of LRP5/6, a key step in inhibiting β-catenin degradation. Using purified Fzd proteins reconstituted in lipid nanodiscs, we investigated the factors that promote the recruitment of Dvl to the plasma membrane. We found that the affinity of Fzd for Dvl was not affected by Wnt ligands, in contrast to other members of the GPCR superfamily for which the binding of extracellular ligands affects the affinity for downstream transducers. Instead, Fzd-Dvl binding was enhanced by increased concentration of the lipid PI(4,5)P2, which is generated by Dvl-associated lipid kinases in response to Wnt and which is required for LRP5/6 phosphorylation. Moreover, binding to Fzd did not promote Dvl DEP domain dimerization, which has been proposed to be required for signaling downstream of Fzd. Our findings suggest a positive feedback loop in which Wnt-stimulated local PI(4,5)P2 production enhances Dvl recruitment and further PI(4,5)P2 production to support Dvl polymerization, LRP5/6 phosphorylation, and β-catenin stabilization.
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Affiliation(s)
- Jacob P Mahoney
- Departments of Structural Biology and Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94035, USA
| | - Elise S Bruguera
- Departments of Structural Biology and Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94035, USA
| | - Mansi Vasishtha
- Departments of Structural Biology and Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94035, USA
| | - Lauren B Killingsworth
- Departments of Structural Biology and Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94035, USA
| | - Saw Kyaw
- Departments of Structural Biology and Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94035, USA
| | - William I Weis
- Departments of Structural Biology and Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94035, USA
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11
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Wang N, Zhou L, Shao CY, Wang XT, Zhang N, Ma J, Hu HL, Wang Y, Qiu M, Shen Y. Potassium channel K ir 4.1 regulates oligodendrocyte differentiation via intracellular pH regulation. Glia 2022; 70:2093-2107. [PMID: 35775976 DOI: 10.1002/glia.24240] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 06/06/2022] [Accepted: 06/24/2022] [Indexed: 11/10/2022]
Abstract
In humans, loss-of-function mutations of Kcnj10 in SeSAME/EAST syndrome, which encodes the inwardly rectifying K+ channel 4.1 (Kir 4.1), causes progressive neurological decline. Despite its rich expression in oligodendrocyte (OL) lineage cells and an emerging link with demyelinating disease, the function of Kir 4.1 in OLs is unclear. Here we show a novel role of Kir 4.1 in OL development. Kir 4.1 expression is markedly greater in OLs than in OL precursor cells (OPCs), and the down-regulation of Kir 4.1 impairs OL maturation by affecting OPC differentiation. Interestingly, Kir 4.1 regulates the intracellular pH of OPCs and OLs via the Na+ /H+ exchanger, which underlies impeded OPC differentiation by Kir 4.1 inhibition. Furthermore, Kir 4.1 regulates GSK3β and SOX10, two molecules critical to OPC development. Collectively, our work opens a new avenue to understanding the functions of Kir 4.1 and intracellular pH in OLs.
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Affiliation(s)
- Na Wang
- Department of Physiology and Department of Neurology of the First Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Liang Zhou
- Department of Physiology and Department of Neurology of the First Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China.,Key Laboratory of Brain Science, Guizhou Institution of Higher Education, Zunyi Medical University, Zunyi, China
| | - Chong-Yu Shao
- Department of Physiology and Department of Neurology of the First Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Xin-Tai Wang
- Department of Physiology and Department of Neurology of the First Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
| | - Nan Zhang
- Key Laboratory of Cranial Cerebral Diseases, Department of Neurobiology of Basic Medical College, Ningxia Medical University, Yinchuan, China
| | - Jiao Ma
- Key Laboratory of Cranial Cerebral Diseases, Department of Neurobiology of Basic Medical College, Ningxia Medical University, Yinchuan, China
| | - Hai-Lan Hu
- Interdisciplinary Institute of Neuroscience and Technology, Qiushi Academy for Advanced Studies, Zhejiang University, Hangzhou, China
| | - Yin Wang
- Key Laboratory of Cranial Cerebral Diseases, Department of Neurobiology of Basic Medical College, Ningxia Medical University, Yinchuan, China
| | - Mengsheng Qiu
- Institute of Life Sciences, Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, China
| | - Ying Shen
- Department of Physiology and Department of Neurology of the First Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou, China
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12
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Lebensohn AM, Bazan JF, Rohatgi R. Receptor control by membrane-tethered ubiquitin ligases in development and tissue homeostasis. Curr Top Dev Biol 2022; 150:25-89. [PMID: 35817504 DOI: 10.1016/bs.ctdb.2022.03.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Paracrine cell-cell communication is central to all developmental processes, ranging from cell diversification to patterning and morphogenesis. Precise calibration of signaling strength is essential for the fidelity of tissue formation during embryogenesis and tissue maintenance in adults. Membrane-tethered ubiquitin ligases can control the sensitivity of target cells to secreted ligands by regulating the abundance of signaling receptors at the cell surface. We discuss two examples of this emerging concept in signaling: (1) the transmembrane ubiquitin ligases ZNRF3 and RNF43 that regulate WNT and bone morphogenetic protein receptor abundance in response to R-spondin ligands and (2) the membrane-recruited ubiquitin ligase MGRN1 that controls Hedgehog and melanocortin receptor abundance. We focus on the mechanistic logic of these systems, illustrated by structural and protein interaction models enabled by AlphaFold. We suggest that membrane-tethered ubiquitin ligases play a widespread role in remodeling the cell surface proteome to control responses to extracellular ligands in diverse biological processes.
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13
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Micka M, Bryja V. Can We Pharmacologically Target Dishevelled: The Key Signal Transducer in the Wnt Pathways? Handb Exp Pharmacol 2021; 269:117-135. [PMID: 34382124 DOI: 10.1007/164_2021_527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dishevelled (DVL) is the central signal transducer in both Wnt/β-catenin-dependent and independent signalling pathways. DVL is required to connect receptor complexes and downstream effectors. Since proximal Wnt pathway components and DVL itself are upregulated in many types of cancer, DVL represents an attractive therapeutic target in the Wnt-addicted cancers and other disorders caused by aberrant Wnt signalling. Here, we discuss progress in several approaches for the modulation of DVL function and hence inhibition of the Wnt signalling. Namely, we sum up the potential of modulation of enzymes that control post-translational modification of DVL - such as inhibition of DVL kinases or promotion of DVL ubiquitination and degradation. In addition, we discuss research directions that can take advantage of direct interaction with the protein domains essential for DVL function: the inhibition of DIX- and DEP-domain mediated polymerization and interaction of DVL PDZ domain with its ligands.
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Affiliation(s)
- Miroslav Micka
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic
| | - Vítězslav Bryja
- Department of Experimental Biology, Faculty of Science, Masaryk University, Brno, Czech Republic. .,Department of Cytokinetics, Institute of Biophysics, Academy of Sciences of the Czech Republic, Brno, Czech Republic.
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14
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Dumortier C, Danopoulos S, Velard F, Al Alam D. Bone Cells Differentiation: How CFTR Mutations May Rule the Game of Stem Cells Commitment? Front Cell Dev Biol 2021; 9:611921. [PMID: 34026749 PMCID: PMC8139249 DOI: 10.3389/fcell.2021.611921] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 04/12/2021] [Indexed: 12/30/2022] Open
Abstract
Cystic fibrosis (CF)-related bone disease has emerged as a significant comorbidity of CF and is characterized by decreased bone formation and increased bone resorption. Both osteoblast and osteoclast differentiations are impacted by cystic fibrosis transmembrane conductance regulator (CFTR) mutations. The defect of CFTR chloride channel or the loss of CFTRs ability to interact with other proteins affect several signaling pathways involved in stem cell differentiation and the commitment of these cells toward bone lineages. Specifically, TGF-, nuclear factor-kappa B (NF-B), PI3K/AKT, and MAPK/ERK signaling are disturbed by CFTR mutations, thus perturbing stem cell differentiation. High inflammation in patients changes myeloid lineage secretion, affecting both myeloid and mesenchymal differentiation. In osteoblast, Wnt signaling is impacted, resulting in consequences for both bone formation and resorption. Finally, CFTR could also have a direct role in osteoclasts resorptive function. In this review, we summarize the existing literature on the role of CFTR mutations on the commitment of induced pluripotent stem cells to bone cells.
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Affiliation(s)
- Claire Dumortier
- Division of Neonatology, Department of Pediatrics, Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA, United States.,Universit de Reims Champagne-Ardenne, BIOS EA 4691, Reims, France
| | - Soula Danopoulos
- Division of Neonatology, Department of Pediatrics, Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA, United States
| | - Frdric Velard
- Universit de Reims Champagne-Ardenne, BIOS EA 4691, Reims, France
| | - Denise Al Alam
- Division of Neonatology, Department of Pediatrics, Lundquist Institute for Biomedical Innovation, Harbor-UCLA Medical Center, Torrance, CA, United States
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15
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Srivastava P, Kane A, Harrison C, Levin M. A Meta-Analysis of Bioelectric Data in Cancer, Embryogenesis, and Regeneration. Bioelectricity 2021; 3:42-67. [PMID: 34476377 DOI: 10.1089/bioe.2019.0034] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Developmental bioelectricity is the study of the endogenous role of bioelectrical signaling in all cell types. Resting potentials and other aspects of ionic cell physiology are known to be important regulatory parameters in embryogenesis, regeneration, and cancer. However, relevant quantitative measurement and genetic phenotyping data are distributed throughout wide-ranging literature, hampering experimental design and hypothesis generation. Here, we analyze published studies on bioelectrics and transcriptomic and genomic/phenotypic databases to provide a novel synthesis of what is known in three important aspects of bioelectrics research. First, we provide a comprehensive list of channelopathies-ion channel and pump gene mutations-in a range of important model systems with developmental patterning phenotypes, illustrating the breadth of channel types, tissues, and phyla (including man) in which bioelectric signaling is a critical endogenous aspect of embryogenesis. Second, we perform a novel bioinformatic analysis of transcriptomic data during regeneration in diverse taxa that reveals an electrogenic protein to be the one common factor specifically expressed in regeneration blastemas across Kingdoms. Finally, we analyze data on distinct Vmem signatures in normal and cancer cells, revealing a specific bioelectrical signature corresponding to some types of malignancies. These analyses shed light on fundamental questions in developmental bioelectricity and suggest new avenues for research in this exciting field.
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Affiliation(s)
- Pranjal Srivastava
- Rye High School, Rye, New York, USA; Current Affiliation: College of Chemistry, University of California, Berkeley, Berkeley, California, USA
| | - Anna Kane
- Department of Biology, Allen Discovery Center, Tufts University, Medford, Massachusetts, USA
| | - Christina Harrison
- Department of Biology, Allen Discovery Center, Tufts University, Medford, Massachusetts, USA
| | - Michael Levin
- Department of Biology, Allen Discovery Center, Tufts University, Medford, Massachusetts, USA
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16
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Han Y, Zhang Z, Liu W, Yao Y, Xu Y, Liu X, Kuang C, Hao X. A Labeling Strategy for Living Specimens in Long-Term/Super-Resolution Fluorescence Imaging. Front Chem 2021; 8:601436. [PMID: 33520932 PMCID: PMC7843436 DOI: 10.3389/fchem.2020.601436] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 12/14/2020] [Indexed: 11/13/2022] Open
Abstract
Despite the urgent need to image living specimens for cutting-edge biological research, most existing fluorescent labeling methods suffer from either poor optical properties or complicated operations required to realize cell-permeability and specificity. In this study, we introduce a method to overcome these limits-taking advantage of the intrinsic affinity of bright and photostable fluorophores, no matter if they are supposed to be live-cell incompatible or not. Incubated with living cells and tissues in particular conditions (concentration and temperature), some Atto and BODIPY dyes show live-cell labeling capability for specific organelles without physical cell-penetration or chemical modifications. Notably, by using Atto 647N as a live-cell mitochondrial marker, we obtain 2.5-time enhancement of brightness and photostability compared with the most commonly used SiR dye in long-term imaging. Our strategy has expanded the scientist's toolbox for understanding the dynamics and interactions of subcellular structures in living specimens.
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Affiliation(s)
- Yubing Han
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China
| | - Zhimin Zhang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China
| | - Wenjie Liu
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China
| | - Yuanfa Yao
- Department of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, China
| | - Yingke Xu
- Department of Biomedical Engineering, Key Laboratory of Biomedical Engineering of Ministry of Education, Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Zhejiang University, Hangzhou, China
| | - Xu Liu
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China.,Ningbo Research Institute, Zhejiang University, Ningbo, China.,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, China
| | - Cuifang Kuang
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China.,Ningbo Research Institute, Zhejiang University, Ningbo, China.,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, China
| | - Xiang Hao
- State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China
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17
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Amiri M, Seidler UE, Nikolovska K. The Role of pH i in Intestinal Epithelial Proliferation-Transport Mechanisms, Regulatory Pathways, and Consequences. Front Cell Dev Biol 2021; 9:618135. [PMID: 33553180 PMCID: PMC7862550 DOI: 10.3389/fcell.2021.618135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Accepted: 01/04/2021] [Indexed: 01/07/2023] Open
Abstract
During the maturation of intestinal epithelial cells along the crypt/surface axis, a multitude of acid/base transporters are differentially expressed in their apical and basolateral membranes, enabling processes of electrolyte, macromolecule, nutrient, acid/base and fluid secretion, and absorption. An intracellular pH (pHi)-gradient is generated along the epithelial crypt/surface axis, either as a consequence of the sum of the ion transport activities or as a distinctly regulated entity. While the role of pHi on proliferation, migration, and tumorigenesis has been explored in cancer cells for some time, emerging evidence suggests an important role of the pHi in the intestinal stem cells (ISCs) proliferative rate under physiological conditions. The present review highlights the current state of knowledge about the potential regulatory role of pHi on intestinal proliferation and differentiation.
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18
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Walentek P. Xenopus epidermal and endodermal epithelia as models for mucociliary epithelial evolution, disease, and metaplasia. Genesis 2021; 59:e23406. [PMID: 33400364 DOI: 10.1002/dvg.23406] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 11/08/2022]
Abstract
The Xenopus embryonic epidermis is a powerful model to study mucociliary biology, development, and disease. Particularly, the Xenopus system is being used to elucidate signaling pathways, transcription factor functions, and morphogenetic mechanisms regulating cell fate specification, differentiation and cell function. Thereby, Xenopus research has provided significant insights into potential underlying molecular mechanisms for ciliopathies and chronic airway diseases. Recent studies have also established the embryonic epidermis as a model for mucociliary epithelial remodeling, multiciliated cell trans-differentiation, cilia loss, and mucus secretion. Additionally, the tadpole foregut epithelium is lined by a mucociliary epithelium, which shows remarkable features resembling mammalian airway epithelia, including its endodermal origin and a variable cell type composition along the proximal-distal axis. This review aims to summarize the advantages of the Xenopus epidermis for mucociliary epithelial biology and disease modeling. Furthermore, the potential of the foregut epithelium as novel mucociliary model system is being highlighted. Additional perspectives are presented on how to expand the range of diseases that can be modeled in the frog system, including proton pump inhibitor-associated pneumonia as well as metaplasia in epithelial cells of the airway and the gastroesophageal region.
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Affiliation(s)
- Peter Walentek
- Renal Division, Department of Medicine, University Hospital Freiburg, Freiburg University Faculty of Medicine, Freiburg, Germany.,CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
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19
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Rapetti-Mauss R, Berenguier C, Allegrini B, Soriani O. Interplay Between Ion Channels and the Wnt/β-Catenin Signaling Pathway in Cancers. Front Pharmacol 2020; 11:525020. [PMID: 33117152 PMCID: PMC7552962 DOI: 10.3389/fphar.2020.525020] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 08/31/2020] [Indexed: 12/12/2022] Open
Abstract
Increasing evidence point out the important roles of ion channels in the physiopathology of cancers, so that these proteins are now considered as potential new therapeutic targets and biomarkers in this disease. Indeed, ion channels have been largely described to participate in many hallmarks of cancers such as migration, invasion, proliferation, angiogenesis, and resistance to apoptosis. At the molecular level, the development of cancers is characterised by alterations in transduction pathways that control cell behaviors. However, the interactions between ion channels and cancer-related signaling pathways are poorly understood so far. Nevertheless, a limited number of reports have recently addressed this important issue, especially regarding the interaction between ion channels and one of the main driving forces for cancer development: the Wnt/β-catenin signaling pathway. In this review, we propose to explore and discuss the current knowledge regarding the interplay between ion channels and the Wnt/β-catenin signaling pathway in cancers.
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20
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Beyond Lipid Signaling: Pleiotropic Effects of Diacylglycerol Kinases in Cellular Signaling. Int J Mol Sci 2020; 21:ijms21186861. [PMID: 32962151 PMCID: PMC7554708 DOI: 10.3390/ijms21186861] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/11/2020] [Accepted: 09/16/2020] [Indexed: 12/13/2022] Open
Abstract
The diacylglycerol kinase family, which can attenuate diacylglycerol signaling and activate phosphatidic acid signaling, regulates various signaling transductions in the mammalian cells. Studies on the regulation of diacylglycerol and phosphatidic acid levels by various enzymes, the identification and characterization of various diacylglycerol and phosphatidic acid-regulated proteins, and the overlap of different diacylglycerol and phosphatidic acid metabolic and signaling processes have revealed the complex and non-redundant roles of diacylglycerol kinases in regulating multiple biochemical and biological networks. In this review article, we summarized recent progress in the complex and non-redundant roles of diacylglycerol kinases, which is expected to aid in restoring dysregulated biochemical and biological networks in various pathological conditions at the bed side.
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21
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Schotthöfer SK, Bohrmann J. Analysing bioelectrical phenomena in the Drosophila ovary with genetic tools: tissue-specific expression of sensors for membrane potential and intracellular pH, and RNAi-knockdown of mechanisms involved in ion exchange. BMC DEVELOPMENTAL BIOLOGY 2020; 20:15. [PMID: 32635900 PMCID: PMC7341674 DOI: 10.1186/s12861-020-00220-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 06/10/2020] [Indexed: 01/16/2023]
Abstract
Background Changes in transcellular bioelectrical patterns are known to play important roles during developmental and regenerative processes. The Drosophila follicular epithelium has proven to be an appropriate model system for studying the mechanisms by which bioelectrical signals emerge and act. Fluorescent indicator dyes in combination with various inhibitors of ion-transport mechanisms have been used to investigate the generation of membrane potentials (Vmem) and intracellular pH (pHi). Both parameters as well as their anteroposterior and dorsoventral gradients were affected by the inhibitors which, in addition, led to alterations of microfilament and microtubule patterns equivalent to those observed during follicle-cell differentiation. Results We expressed two genetically-encoded fluorescent sensors for Vmem and pHi, ArcLight and pHluorin-Moesin, in the follicular epithelium of Drosophila. By means of the respective inhibitors, we obtained comparable effects on Vmem and/or pHi as previously described for Vmem- and pHi-sensitive fluorescent dyes. In a RNAi-knockdown screen, five genes of ion-transport mechanisms and gap-junction subunits were identified exerting influence on ovary development and/or oogenesis. Loss of ovaries or small ovaries were the results of soma knockdowns of the innexins inx1 and inx3, and of the DEG/ENaC family member ripped pocket (rpk). Germline knockdown of rpk also resulted in smaller ovaries. Soma knockdown of the V-ATPase-subunit vha55 caused size-reduced ovaries with degenerating follicles from stage 10A onward. In addition, soma knockdown of the open rectifier K+channel 1 (ork1) resulted in a characteristic round-egg phenotype with altered microfilament and microtubule organisation in the follicular epithelium. Conclusions The genetic tool box of Drosophila provides means for a refined and extended analysis of bioelectrical phenomena. Tissue-specifically expressed Vmem- and pHi-sensors exhibit some practical advantages compared to fluorescent indicator dyes. Their use confirms that the ion-transport mechanisms targeted by inhibitors play important roles in the generation of bioelectrical signals. Moreover, modulation of bioelectrical signals via RNAi-knockdown of genes coding for ion-transport mechanisms and gap-junction subunits exerts influence on crucial processes during ovary development and results in cytoskeletal changes and altered follicle shape. Thus, further evidence amounts for bioelectrical regulation of developmental processes via the control of both signalling pathways and cytoskeletal organisation.
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Affiliation(s)
- Susanne Katharina Schotthöfer
- RWTH Aachen University, Institut für Biologie II, Abt. Zoologie und Humanbiologie, Worringerweg 3, 52056, Aachen, Germany
| | - Johannes Bohrmann
- RWTH Aachen University, Institut für Biologie II, Abt. Zoologie und Humanbiologie, Worringerweg 3, 52056, Aachen, Germany.
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22
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Activity of Smurf2 Ubiquitin Ligase Is Regulated by the Wnt Pathway Protein Dishevelled. Cells 2020; 9:cells9051147. [PMID: 32392721 PMCID: PMC7290506 DOI: 10.3390/cells9051147] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/01/2020] [Accepted: 05/04/2020] [Indexed: 01/17/2023] Open
Abstract
Wnt and BMP signaling pathways are two key molecular machineries regulating development and homeostasis. The efficient coordination of Wnt and BMP is essential in many developmental processes such as establishment of antero-posterior and dorso-ventral body axis, regulation of convergent extension, or development of various organ systems. SMAD ubiquitination regulatory factor (Smurf) family of E3 ubiquitin ligases are important and evolutionary conserved regulators of TGF-β/BMP signaling pathways. Smurf2 has been previously shown to regulate Wnt/planar cell polarity (PCP) signaling pathway by ubiquitinating Prickle1, one of the key components of PCP. We explored the role of Smurf2 in Wnt pathways in further detail and identified that Smurf2 is also a ubiquitin ligase of Dishevelled (DVL), the key cytoplasmic signal transducer in the Wnt pathway. Interestingly, the Smurf2 and DVL relationship expands beyond substrate-E3 ligase. We can show that DVL activates Smurf2, which allows Smurf2 to ubiquitinate its substrates from Wnt/PCP (Prickle1) as well as TGF-β/BMP (Smad2) pathways more efficiently. Using SMAD7 as an example of Smurf2 activator we show that DVL and SMAD7 both activates Smurf2 activity. In HEK293 cells the deficiency of DVL phenocopies absence of Smurf2 and leads to the increased phosphorylation of R-Smads. Smurf2-DVL connection provides a novel and intriguing point of crosstalk for Wnt and BMP pathways.
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23
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Humphries AC, Narang S, Mlodzik M. Mutations associated with human neural tube defects display disrupted planar cell polarity in Drosophila. eLife 2020; 9:e53532. [PMID: 32234212 PMCID: PMC7180057 DOI: 10.7554/elife.53532] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 03/31/2020] [Indexed: 02/06/2023] Open
Abstract
Planar cell polarity (PCP) and neural tube defects (NTDs) are linked, with a subset of NTD patients found to harbor mutations in PCP genes, but there is limited data on whether these mutations disrupt PCP signaling in vivo. The core PCP gene Van Gogh (Vang), Vangl1/2 in mammals, is the most specific for PCP. We thus addressed potential causality of NTD-associated Vangl1/2 mutations, from either mouse or human patients, in Drosophila allowing intricate analysis of the PCP pathway. Introducing the respective mammalian mutations into Drosophila Vang revealed defective phenotypic and functional behaviors, with changes to Vang localization, post-translational modification, and mechanistic function, such as its ability to interact with PCP effectors. Our findings provide mechanistic insight into how different mammalian mutations contribute to developmental disorders and strengthen the link between PCP and NTD. Importantly, analyses of the human mutations revealed that each is a causative factor for the associated NTD.
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Affiliation(s)
- Ashley C Humphries
- Department of Cell, Developmental and Regenerative BiologyNew YorkUnited States
- Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Graduate School of Biomedical SciencesNew YorkUnited States
| | - Sonali Narang
- Department of Cell, Developmental and Regenerative BiologyNew YorkUnited States
- Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Graduate School of Biomedical SciencesNew YorkUnited States
| | - Marek Mlodzik
- Department of Cell, Developmental and Regenerative BiologyNew YorkUnited States
- Icahn School of Medicine at Mount SinaiNew YorkUnited States
- Graduate School of Biomedical SciencesNew YorkUnited States
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24
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Raja DA, Gotherwal V, Burse SA, Subramaniam YJ, Sultan F, Vats A, Gautam H, Sharma B, Sharma S, Singh A, Sivasubbu S, Gokhale RS, Natarajan VT. pH-controlled histone acetylation amplifies melanocyte differentiation downstream of MITF. EMBO Rep 2020; 21:e48333. [PMID: 31709752 PMCID: PMC6945066 DOI: 10.15252/embr.201948333] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2019] [Revised: 10/04/2019] [Accepted: 10/15/2019] [Indexed: 12/20/2022] Open
Abstract
Tanning response and melanocyte differentiation are mediated by the central transcription factor MITF. This involves the rapid and selective induction of melanocyte maturation genes, while concomitantly the expression of other effector genes is maintained. In this study, using cell-based and zebrafish model systems, we report on a pH-mediated feed-forward mechanism of epigenetic regulation that enables selective amplification of the melanocyte maturation program. We demonstrate that MITF activation directly elevates the expression of the enzyme carbonic anhydrase 14 (CA14). Nuclear localization of CA14 leads to an increase of the intracellular pH, resulting in the activation of the histone acetyl transferase p300/CBP. In turn, enhanced H3K27 histone acetylation at selected differentiation genes facilitates their amplified expression via MITF. CRISPR-mediated targeted missense mutation of CA14 in zebrafish results in the formation of immature acidic melanocytes with decreased pigmentation, establishing a central role for this mechanism during melanocyte differentiation in vivo. Thus, we describe an epigenetic control system via pH modulation that reinforces cell fate determination by altering chromatin dynamics.
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Affiliation(s)
- Desingu Ayyappa Raja
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
| | - Vishvabandhu Gotherwal
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
| | - Shaunak A Burse
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
| | - Yogaspoorthi J Subramaniam
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
| | - Farina Sultan
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
| | - Archana Vats
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
| | - Hemlata Gautam
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
| | - Babita Sharma
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
| | - Sachin Sharma
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
- Present address:
National Institute of ImmunologyNew DelhiIndia
| | - Archana Singh
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
| | | | - Rajesh S Gokhale
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Present address:
National Institute of ImmunologyNew DelhiIndia
| | - Vivek T Natarajan
- CSIR‐Institute of Genomics and Integrative BiologyNew DelhiIndia
- Academy of Scientific and Innovative ResearchTaramani, Chennai
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25
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Familial Exudative Vitreoretinopathy-Related Disease-Causing Genes and Norrin/ β-Catenin Signal Pathway: Structure, Function, and Mutation Spectrums. J Ophthalmol 2019; 2019:5782536. [PMID: 31827910 PMCID: PMC6885210 DOI: 10.1155/2019/5782536] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 09/07/2019] [Accepted: 09/26/2019] [Indexed: 02/06/2023] Open
Abstract
Familial exudative vitreoretinopathy (FEVR) is a hereditary ocular disorder characterized by incomplete vascularization/abnormality of peripheral retina. Four of the identified disease-causing genes of FEVR were NDP, FZD4, LRP5, and TSPAN12, the protein coded by which were the components of the Norrin/β-catenin signal pathway. In this review, we summarized and discussed the spectrum of mutations involving these four genes. By the end of 2017, the number of FEVR causing mutations reported for NDP, FZD4, LRP5, and TSPAN12 was, respectively, 26, 121, 58, and 40. Three most frequently reported mutations were c. 362G > A (p.R121Q) of NDP, c. 313A > G (p.M105V), and c.1282_1285delGACA (p.D428SfsX2) of FZD4. Mutations have a tendency to cluster in some “hotspots” domains which may be responsible for protein interactions.
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26
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Pedersen SF, Counillon L. The SLC9A-C Mammalian Na +/H + Exchanger Family: Molecules, Mechanisms, and Physiology. Physiol Rev 2019; 99:2015-2113. [PMID: 31507243 DOI: 10.1152/physrev.00028.2018] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Na+/H+ exchangers play pivotal roles in the control of cell and tissue pH by mediating the electroneutral exchange of Na+ and H+ across cellular membranes. They belong to an ancient family of highly evolutionarily conserved proteins, and they play essential physiological roles in all phyla. In this review, we focus on the mammalian Na+/H+ exchangers (NHEs), the solute carrier (SLC) 9 family. This family of electroneutral transporters constitutes three branches: SLC9A, -B, and -C. Within these, each isoform exhibits distinct tissue expression profiles, regulation, and physiological roles. Some of these transporters are highly studied, with hundreds of original articles, and some are still only rudimentarily understood. In this review, we present and discuss the pioneering original work as well as the current state-of-the-art research on mammalian NHEs. We aim to provide the reader with a comprehensive view of core knowledge and recent insights into each family member, from gene organization over protein structure and regulation to physiological and pathophysiological roles. Particular attention is given to the integrated physiology of NHEs in the main organ systems. We provide several novel analyses and useful overviews, and we pinpoint main remaining enigmas, which we hope will inspire novel research on these highly versatile proteins.
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Affiliation(s)
- S F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
| | - L Counillon
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
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27
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Kozielewicz P, Turku A, Schulte G. Molecular Pharmacology of Class F Receptor Activation. Mol Pharmacol 2019; 97:62-71. [PMID: 31591260 DOI: 10.1124/mol.119.117986] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 09/25/2019] [Indexed: 12/29/2022] Open
Abstract
The class Frizzled (FZD) or class F of G protein-coupled receptors consists of 10 FZD paralogues and Smoothened (SMO). FZDs coordinate wingless/Int-1 signaling and SMO mediates Hedgehog signaling. Class F receptor signaling is intrinsically important for embryonic development and its dysregulation leads to diseases, including diverse forms of tumors. With regard to the importance of class F signaling in human disease, these receptors provide an attractive target for therapeutics, exemplified by the use of SMO antagonists for the treatment of basal cell carcinoma. Here, we review recent structural insights in combination with a more detailed functional understanding of class F receptor activation, G protein coupling, conformation-based functional selectivity, and mechanistic details of activating cancer mutations, which will lay the basis for further development of class F-targeting small molecules for human therapy. SIGNIFICANCE STATEMENT: Stimulated by recent insights into the activation mechanisms of class F receptors from structural and functional analysis of Frizzled and Smoothened, we aim to summarize what we know about the molecular details of ligand binding, agonist-driven conformational changes, and class F receptor activation. A better understanding of receptor activation mechanisms will allow us to engage in structure- and mechanism-driven drug discovery with the potential to develop more isoform-selective and potentially pathway-selective drugs for human therapy.
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Affiliation(s)
- Pawel Kozielewicz
- Section of Receptor Biology and Signaling, Department Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Ainoleena Turku
- Section of Receptor Biology and Signaling, Department Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Gunnar Schulte
- Section of Receptor Biology and Signaling, Department Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
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Alkylglycerol monooxygenase, a heterotaxy candidate gene, regulates left-right patterning via Wnt signaling. Dev Biol 2019; 456:1-7. [PMID: 31398317 DOI: 10.1016/j.ydbio.2019.07.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 07/08/2019] [Accepted: 07/31/2019] [Indexed: 12/30/2022]
Abstract
Congenital heart disease (CHD) is a major cause of morbidity in the pediatric population yet its genetic and molecular causes remain poorly defined. Previously, we identified AGMO as a candidate heterotaxy disease gene, a disorder of left-right (LR) patterning that can have a profound effect on cardiac function. AGMO is the only known alkylglycerol monooxygenase, an orphan tetrahydrobiopterin dependent enzyme that cleaves the ether linkage in alkylglycerols. However, whether AGMO plays a role in LR patterning was unexplored. Here we reveal that Agmo is required for correct development of the embryonic LR axis in Xenopus embryos recapitulating the patient's heterotaxy phenotype. Mechanistically, we demonstrate that Agmo is a regulator of canonical Wnt signaling, required during gastrulation for normal formation of the left - right organizer. Mutational analysis demonstrates that this function is dependent on Agmo's alkylglycerol monooxygenase activity. Together, our findings identify Agmo as a regulator of canonical Wnt signaling, demonstrate a role for Agmo in embryonic axis formation, and provide insight into the poorly understood developmental requirements for ether lipid cleavage.
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Electrochemical patterns during Drosophila oogenesis: ion-transport mechanisms generate stage-specific gradients of pH and membrane potential in the follicle-cell epithelium. BMC DEVELOPMENTAL BIOLOGY 2019; 19:12. [PMID: 31226923 PMCID: PMC6588877 DOI: 10.1186/s12861-019-0192-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 06/06/2019] [Indexed: 12/14/2022]
Abstract
Background Alterations of bioelectrical properties of cells and tissues are known to function as wide-ranging signals during development, regeneration and wound-healing in several species. The Drosophila follicle-cell epithelium provides an appropriate model system for studying the potential role of electrochemical signals, like intracellular pH (pHi) and membrane potential (Vmem), during development. Therefore, we analysed stage-specific gradients of pHi and Vmem as well as their dependence on specific ion-transport mechanisms. Results Using fluorescent indicators, we found distinct alterations of pHi- and Vmem-patterns during stages 8 to 12 of oogenesis. To determine the roles of relevant ion-transport mechanisms in regulating pHi and Vmem and in establishing stage-specific antero-posterior and dorso-ventral gradients, we used inhibitors of Na+/H+-exchangers and Na+-channels (amiloride), V-ATPases (bafilomycin), ATP-sensitive K+-channels (glibenclamide), voltage-dependent L-type Ca2+-channels (verapamil), Cl−-channels (9-anthroic acid) and Na+/K+/2Cl−-cotransporters (furosemide). Either pHi or Vmem or both parameters were affected by each tested inhibitor. While the inhibition of Na+/H+-exchangers (NHE) and amiloride-sensitive Na+-channels or of V-ATPases resulted in relative acidification, inhibiting the other ion-transport mechanisms led to relative alkalisation. The most prominent effects on pHi were obtained by inhibiting Na+/K+/2Cl−-cotransporters or ATP-sensitive K+-channels. Vmem was most efficiently hyperpolarised by inhibiting voltage-dependent L-type Ca2+-channels or ATP-sensitive K+-channels, whereas the impact of the other ion-transport mechanisms was smaller. In case of very prominent effects of inhibitors on pHi and/or Vmem, we also found strong influences on the antero-posterior and dorso-ventral pHi- and/or Vmem-gradients. For example, inhibiting ATP-sensitive K+-channels strongly enhanced both pHi-gradients (increasing alkalisation) and reduced both Vmem-gradients (increasing hyperpolarisation). Similarly, inhibiting Na+/K+/2Cl−-cotransporters strongly enhanced both pHi-gradients and reduced the antero-posterior Vmem-gradient. To minor extents, both pHi-gradients were enhanced and both Vmem-gradients were reduced by inhibiting voltage-dependent L-type Ca2+-channels, whereas only both pHi-gradients were reduced (increasing acidification) by inhibiting V-ATPases or NHE and Na+-channels. Conclusions Our data show that in the Drosophila follicle-cell epithelium stage-specific pHi- and Vmem-gradients develop which result from the activity of several ion-transport mechanisms. These gradients are supposed to represent important bioelectrical cues during oogenesis, e.g., by serving as electrochemical prepatterns in modifying cell polarity and cytoskeletal organisation. Electronic supplementary material The online version of this article (10.1186/s12861-019-0192-x) contains supplementary material, which is available to authorized users.
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Levin M, Pietak AM, Bischof J. Planarian regeneration as a model of anatomical homeostasis: Recent progress in biophysical and computational approaches. Semin Cell Dev Biol 2019; 87:125-144. [PMID: 29635019 PMCID: PMC6234102 DOI: 10.1016/j.semcdb.2018.04.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 04/03/2018] [Accepted: 04/06/2018] [Indexed: 12/22/2022]
Abstract
Planarian behavior, physiology, and pattern control offer profound lessons for regenerative medicine, evolutionary biology, morphogenetic engineering, robotics, and unconventional computation. Despite recent advances in the molecular genetics of stem cell differentiation, this model organism's remarkable anatomical homeostasis provokes us with truly fundamental puzzles about the origin of large-scale shape and its relationship to the genome. In this review article, we first highlight several deep mysteries about planarian regeneration in the context of the current paradigm in this field. We then review recent progress in understanding of the physiological control of an endogenous, bioelectric pattern memory that guides regeneration, and how modulating this memory can permanently alter the flatworm's target morphology. Finally, we focus on computational approaches that complement reductive pathway analysis with synthetic, systems-level understanding of morphological decision-making. We analyze existing models of planarian pattern control and highlight recent successes and remaining knowledge gaps in this interdisciplinary frontier field.
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Affiliation(s)
- Michael Levin
- Allen Discovery Center at Tufts University, Medford, MA 02155, United States; Biology Department, Tufts University, Medford, MA 02155, United States.
| | - Alexis M Pietak
- Allen Discovery Center at Tufts University, Medford, MA 02155, United States
| | - Johanna Bischof
- Allen Discovery Center at Tufts University, Medford, MA 02155, United States; Biology Department, Tufts University, Medford, MA 02155, United States
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31
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Clemens MM, Kennon-McGill S, Apte U, James LP, Finck BN, McGill MR. The inhibitor of glycerol 3-phosphate acyltransferase FSG67 blunts liver regeneration after acetaminophen overdose by altering GSK3β and Wnt/β-catenin signaling. Food Chem Toxicol 2019; 125:279-288. [PMID: 30654094 PMCID: PMC6443093 DOI: 10.1016/j.fct.2019.01.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Revised: 12/23/2018] [Accepted: 01/13/2019] [Indexed: 12/15/2022]
Abstract
Repair mechanisms after acetaminophen (APAP) hepatotoxicity are poorly understood. We recently discovered that phosphatidic acid (PA) increases in mice and humans after APAP overdose, and is critical for liver regeneration. Here, we hypothesized that PA inhibits glycogen synthase kinase-3β (GSK3β), a component of canonical Wnt/β-catenin signaling, after APAP overdose. To test that, we treated mice with 300 mg/kg APAP at 0 h followed by vehicle or 20 mg/kg of the glycerol 3-phosphate acyltransferase inhibitor FSG67 at 3, 24 and 48 h. Some mice also received the GSK3 inhibitor L803-mts. Blood and liver were collected at multiple time points. Consistent with our earlier results, FSG67 did not affect toxicity (ALT, histology), APAP bioactivation (total glutathione), or oxidative stress (oxidized glutathione), but did reduce expression of proliferating cell nuclear antigen (PCNA) at 52 h. We then measured GSK3β phosphorylation and found it was dramatically decreased by FSG67 at 24 h, before PCNA dropped. Expression of cyclin D1, downstream of Wnt/β-catenin, was also reduced. To determine if the effect of FSG67 on GSK3β is important, we treated mice with FSG67 and L803-mts after APAP. Importantly, L803-mts rescued hepatocyte proliferation and survival. Our data indicate PA and lysoPA may support recovery after APAP overdose by inhibiting GSK3β.
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Affiliation(s)
- Melissa M Clemens
- Dept. of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Interdisciplinary Biomedical Sciences Graduate Program, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Stefanie Kennon-McGill
- Dept. of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Udayan Apte
- Dept. of Pharmacology, Toxicology, and Therapeutics, School of Medicine, University of Kansas Medical Center, Kansas City, KS, USA
| | - Laura P James
- Dept. of Pediatrics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Brian N Finck
- Div. of Geriatrics and Nutritional Sciences, Dept. of Internal Medicine, Washington University School of Medicine, St. Louis, MO, USA
| | - Mitchell R McGill
- Dept. of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Dept. of Environmental and Occupational Health, Fay W. Boozman College of Public Health, University of Arkansas for Medical Sciences, Little Rock, AR, USA; Center for Dietary Supplement Research, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
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32
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Dragwidge JM, Scholl S, Schumacher K, Gendall AR. NHX-type Na+(K+)/H+ antiporters are required for TGN/EE trafficking and endosomal ion homeostasis in Arabidopsis. J Cell Sci 2019; 132:jcs.226472. [DOI: 10.1242/jcs.226472] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 02/21/2019] [Indexed: 12/17/2022] Open
Abstract
The regulation of ion and pH homeostasis of endomembrane organelles is critical for functional protein trafficking, sorting and modification in eukaryotic cells. pH homeostasis is maintained through the activity of vacuolar H+-ATPases (V-ATPases) pumping protons (H+) into the endomembrane lumen, and counter-action by cation/proton exchangers such as the NHX family of Na+(K+)/H+ exchangers. In plants, V-ATPase activity at the trans-Golgi network/early endosome (TGN/EE) is important for secretory and endocytic trafficking, however the role of the endosomal antiporters NHX5 and NHX6 in endomembrane trafficking is unclear. Here we show through genetic, pharmacological, and live-cell imaging approaches that double knockout of NHX5 and NHX6 results in the impairment of endosome motility, protein recycling at the TGN/EE, but not in the secretion of integral membrane proteins. Furthermore, we report that nhx5 nhx6 mutants are partially insensitive to osmotic swelling of TGN/EE induced by the monovalent cation ionophore monensin, and to late endosomal swelling by the phosphatidylinositol 3/4-kinase inhibitor wortmannin, demonstrating that NHX5 and NHX6 function to regulate the luminal cation composition of endosomes.
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Affiliation(s)
- Jonathan Michael Dragwidge
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBiosciences, 5 Ring Road, La Trobe University, Bundoora, VIC 3086, Australia
- Department of Plant Developmental Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - Stefan Scholl
- Department of Plant Developmental Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - Karin Schumacher
- Department of Plant Developmental Biology, Centre for Organismal Studies, Heidelberg University, 69120 Heidelberg, Germany
| | - Anthony Richard Gendall
- Department of Animal, Plant and Soil Sciences, AgriBio, Centre for AgriBiosciences, 5 Ring Road, La Trobe University, Bundoora, VIC 3086, Australia
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33
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Merida I, Arranz-Nicolás J, Torres-Ayuso P, Ávila-Flores A. Diacylglycerol Kinase Malfunction in Human Disease and the Search for Specific Inhibitors. Handb Exp Pharmacol 2019; 259:133-162. [PMID: 31227890 DOI: 10.1007/164_2019_221] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The diacylglycerol kinases (DGKs) are master regulator kinases that control the switch from diacylglycerol (DAG) to phosphatidic acid (PA), two lipids with important structural and signaling properties. Mammalian DGKs distribute into five subfamilies that regulate local availability of DAG and PA pools in a tissue- and subcellular-restricted manner. Pharmacological manipulation of DGK activity holds great promise, given the critical contribution of specific DGK subtypes to the control of membrane structure, signaling complexes, and cell-cell communication. The latest advances in the DGK field have unveiled the differential contribution of selected isoforms to human disease. Defects in the expression/activity of individual DGK isoforms contribute substantially to cognitive impairment, mental disorders, insulin resistance, and vascular pathologies. Abnormal DGK overexpression, on the other hand, confers the acquisition of malignant traits including invasion, chemotherapy resistance, and inhibition of immune attack on tumors. Translation of these findings into therapeutic approaches will require development of methods to pharmacologically modulate DGK functions. In particular, inhibitors that target the DGKα isoform hold particular promise in the fight against cancer, on their own or in combination with immune-targeting therapies.
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Affiliation(s)
- Isabel Merida
- Department of Immunology and Oncology, National Center of Biotechnology (CNB-CSIC), Madrid, Spain.
| | - Javier Arranz-Nicolás
- Department of Immunology and Oncology, National Center of Biotechnology (CNB-CSIC), Madrid, Spain
| | - Pedro Torres-Ayuso
- Laboratory of Cell and Developmental Signaling, National Cancer Institute (NCI-NIH), Frederick, MD, USA
| | - Antonia Ávila-Flores
- Department of Immunology and Oncology, National Center of Biotechnology (CNB-CSIC), Madrid, Spain
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34
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Valnohova J, Kowalski-Jahn M, Sunahara RK, Schulte G. Functional dissection of the N-terminal extracellular domains of Frizzled 6 reveals their roles for receptor localization and Dishevelled recruitment. J Biol Chem 2018; 293:17875-17887. [PMID: 30237173 PMCID: PMC6240854 DOI: 10.1074/jbc.ra118.004763] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 09/18/2018] [Indexed: 11/06/2022] Open
Abstract
The Frizzled (FZD) proteins belong to class F of G protein-coupled receptors (GPCRs) and are essential for various pathways involving the secreted lipoglycoproteins of the wingless/int-1 (WNT) family. A WNT-binding cysteine-rich domain (CRD) in FZDs is N-terminally located and connected to the seven transmembrane domain-spanning receptor core by a linker domain that has a variable length in different FZD homologs. However, the function and importance of this linker domain are poorly understood. Here we used systematic mutagenesis of FZD6 to define the minimal N-terminal domain sufficient for receptor surface expression and recruitment of the intracellular scaffold protein Dishevelled (DVL). Further, we identified a triad of evolutionarily conserved cysteines in the FZD linker domain that is crucial for receptor membrane expression and recruitment of DVL. Our results are in agreement with the concept that the conserved cysteines in the linker domain of FZDs assist with the formation of a common secondary structure in this region. We propose that this structure could be involved in agonist binding and receptor activation mechanisms that are similar to the binding and activation mechanisms known for other GPCRs.
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Affiliation(s)
- Jana Valnohova
- From the Section for Receptor Biology and Signaling, Department of Physiology and Pharmacology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Maria Kowalski-Jahn
- From the Section for Receptor Biology and Signaling, Department of Physiology and Pharmacology, Karolinska Institutet, 171 65 Stockholm, Sweden
| | - Roger K Sunahara
- Department of Pharmacology, University of California San Diego School of Medicine, La Jolla, California 92093
| | - Gunnar Schulte
- From the Section for Receptor Biology and Signaling, Department of Physiology and Pharmacology, Karolinska Institutet, 171 65 Stockholm, Sweden.
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35
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White KA, Grillo-Hill BK, Esquivel M, Peralta J, Bui VN, Chire I, Barber DL. β-Catenin is a pH sensor with decreased stability at higher intracellular pH. J Cell Biol 2018; 217:3965-3976. [PMID: 30315137 PMCID: PMC6219716 DOI: 10.1083/jcb.201712041] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2017] [Revised: 07/16/2018] [Accepted: 08/31/2018] [Indexed: 02/08/2023] Open
Abstract
White et al. find that intracellular pH regulates the stability of β-catenin, the Wnt signaling molecule that controls cell polarity, adhesion, and differentiation. A conserved histidine residue in β-catenin mediates pH-dependent binding to the E3 ligase β-TrCP for degradation, and a cancer-associated mutation that bypasses this pH-sensitive regulation induces ectopic tumors in the Drosophila eye. β-Catenin functions as an adherens junction protein for cell–cell adhesion and as a signaling protein. β-catenin function is dependent on its stability, which is regulated by protein–protein interactions that stabilize β-catenin or target it for proteasome-mediated degradation. In this study, we show that β-catenin stability is regulated by intracellular pH (pHi) dynamics, with decreased stability at higher pHi in both mammalian cells and Drosophila melanogaster. β-Catenin degradation requires phosphorylation of N-terminal residues for recognition by the E3 ligase β-TrCP. While β-catenin phosphorylation was pH independent, higher pHi induced increased β-TrCP binding and decreased β-catenin stability. An evolutionarily conserved histidine in β-catenin (found in the β-TrCP DSGIHS destruction motif) is required for pH-dependent binding to β-TrCP. Expressing a cancer-associated H36R–β-catenin mutant in the Drosophila eye was sufficient to induce Wnt signaling and produced pronounced tumors not seen with other oncogenic β-catenin alleles. We identify pHi dynamics as a previously unrecognized regulator of β-catenin stability, functioning in coincidence with phosphorylation.
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Affiliation(s)
- Katharine A White
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA
| | - Bree K Grillo-Hill
- Department of Biological Sciences, San Jose State University, San Jose, CA
| | - Mario Esquivel
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA
| | - Jobelle Peralta
- Department of Biological Sciences, San Jose State University, San Jose, CA
| | - Vivian N Bui
- Department of Biological Sciences, San Jose State University, San Jose, CA
| | - Ismahan Chire
- Department of Biological Sciences, San Jose State University, San Jose, CA
| | - Diane L Barber
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA
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36
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Strakova K, Kowalski-Jahn M, Gybel T, Valnohova J, Dhople VM, Harnos J, Bernatik O, Ganji RS, Zdrahal Z, Mulder J, Lindskog C, Bryja V, Schulte G. Dishevelled enables casein kinase 1-mediated phosphorylation of Frizzled 6 required for cell membrane localization. J Biol Chem 2018; 293:18477-18493. [PMID: 30309985 DOI: 10.1074/jbc.ra118.004656] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Revised: 10/05/2018] [Indexed: 11/06/2022] Open
Abstract
Frizzleds (FZDs) are receptors for secreted lipoglycoproteins of the Wingless/Int-1 (WNT) family, initiating an important signal transduction network in multicellular organisms. FZDs are G protein-coupled receptors (GPCRs), which are well known to be regulated by phosphorylation, leading to specific downstream signaling or receptor desensitization. The role and underlying mechanisms of FZD phosphorylation remain largely unexplored. Here, we investigated the phosphorylation of human FZD6 Using MS analysis and a phospho-state- and -site-specific antibody, we found that Ser-648, located in the FZD6 C terminus, is efficiently phosphorylated by casein kinase 1 ϵ (CK1ϵ) and that this phosphorylation requires the scaffolding protein Dishevelled (DVL). In an overexpression system, DVL1, -2, and -3 promoted CK1ϵ-mediated FZD6 phosphorylation on Ser-648. This DVL activity required an intact DEP domain and FZD-mediated recruitment of this domain to the cell membrane. Substitution of the CK1ϵ-targeted phosphomotif reduced FZD6 surface expression, suggesting that Ser-648 phosphorylation controls membrane trafficking of FZD6 Phospho-Ser-648 FZD6 immunoreactivity in human fallopian tube epithelium was predominantly apical, associated with cilia in a subset of epithelial cells, compared with the total FZD6 protein expression, suggesting that FZD6 phosphorylation contributes to asymmetric localization of receptor function within the cell and to epithelial polarity. Given the key role of FZD6 in planar cell polarity, our results raise the possibility that asymmetric phosphorylation of FZD6 rather than asymmetric protein distribution accounts for polarized receptor signaling.
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Affiliation(s)
- Katerina Strakova
- From the Laboratory of WNT Signaling, Institute of Experimental Biology, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic.,Section for Receptor Biology and Signaling, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum (6D), Tomtebodavägen 16, SE-17165 Stockholm, Sweden
| | - Maria Kowalski-Jahn
- Section for Receptor Biology and Signaling, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum (6D), Tomtebodavägen 16, SE-17165 Stockholm, Sweden
| | - Tomas Gybel
- From the Laboratory of WNT Signaling, Institute of Experimental Biology, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic
| | - Jana Valnohova
- Section for Receptor Biology and Signaling, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum (6D), Tomtebodavägen 16, SE-17165 Stockholm, Sweden
| | - Vishnu M Dhople
- Department of Functional Genomics, Interfaculty Institute for Genetics and Functional Genomics, Ernst Moritz Arndt University of Greifswald, Friedrich-Ludwig-Jahn-Strasse 15, 17487 Greifswald, Germany
| | - Jakub Harnos
- From the Laboratory of WNT Signaling, Institute of Experimental Biology, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic
| | - Ondrej Bernatik
- From the Laboratory of WNT Signaling, Institute of Experimental Biology, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic
| | - Ranjani Sri Ganji
- From the Laboratory of WNT Signaling, Institute of Experimental Biology, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic.,Central European Institute for Technology, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic
| | - Zbynek Zdrahal
- Central European Institute for Technology, Masaryk University, Kamenice 5, 62500 Brno, Czech Republic
| | - Jan Mulder
- Science for Life Laboratory, Department of Neuroscience, Karolinska Institute, Tomtebodavägen 16 17165 Stockholm, Sweden, and
| | - Cecilia Lindskog
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Science for Life Laboratory, Uppsala University, Dag Hammarskjölds väg 20, 751 85 Uppsala, Sweden
| | - Vitezslav Bryja
- From the Laboratory of WNT Signaling, Institute of Experimental Biology, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic,
| | - Gunnar Schulte
- From the Laboratory of WNT Signaling, Institute of Experimental Biology, Faculty of Science, Masaryk University, Kotlarska 2, 61137 Brno, Czech Republic, .,Section for Receptor Biology and Signaling, Department of Physiology and Pharmacology, Karolinska Institutet, Biomedicum (6D), Tomtebodavägen 16, SE-17165 Stockholm, Sweden
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37
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Sun DI, Tasca A, Haas M, Baltazar G, Harland RM, Finkbeiner WE, Walentek P. Na+/H+ Exchangers Are Required for the Development and Function of Vertebrate Mucociliary Epithelia. Cells Tissues Organs 2018; 205:279-292. [PMID: 30300884 DOI: 10.1159/000492973] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/19/2018] [Indexed: 11/19/2022] Open
Abstract
Na+/H+ exchangers (NHEs) represent a highly conserved family of ion transporters that regulate pH homeostasis. NHEs as well as other proton transporters were previously linked to the regulation of the Wnt signaling pathway, cell polarity signaling, and mucociliary function. Furthermore, mutations in the gene SLC9A3 (encoding NHE3) were detected as additional risk factors for airway infections in cystic fibrosis patients. Here, we used the Xenopus embryonic mucociliary epidermis as well as human airway epithelial cells (HAECs) as models to investigate the functional roles of NHEs in mucociliary development and regeneration. In Xenopus embryos, NHEs 1-3 were expressed during epidermal development, and loss of NHE function impaired mucociliary clearance in tadpoles. Clearance defects were caused by reduced cilia formation, disrupted alignment of basal bodies in multiciliated cells (MCCs), and dysregulated mucociliary gene expression. These data also suggested that NHEs may contribute to the activation of Wnt signaling in mucociliary epithelia. In HAECs, pharmacological inhibition of NHE function also caused defective ciliation and regeneration in airway MCCs. Collectively, our data revealed a requirement for NHEs in vertebrate mucociliary epithelia and linked NHE activity to cilia formation and function in differentiating MCCs. Our results provide an entry point for the understanding of the contribution of NHEs to signaling, development, and pathogenesis in the human respiratory tract.
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Affiliation(s)
- Dingyuan I Sun
- Genetics, Genomics and Development Division, Molecular and Cell Biology Department, University of California, Berkeley, California, USA.,Department of Pathology, University of California, San Francisco, California, USA
| | - Alexia Tasca
- Renal Division, Department of Medicine, University Freiburg Medical Center and ZBSA - Center for Systems Biological Analysis, Freiburg, Germany
| | - Maximilian Haas
- Renal Division, Department of Medicine, University Freiburg Medical Center and ZBSA - Center for Systems Biological Analysis, Freiburg, Germany.,Spemann Graduate School of Biology and Medicine, Albert Ludwigs University Freiburg, Freiburg, Germany
| | - Grober Baltazar
- Genetics, Genomics and Development Division, Molecular and Cell Biology Department, University of California, Berkeley, California, USA.,Children's Medical Research Institute, Westmead, New South Wales, Australia
| | - Richard M Harland
- Genetics, Genomics and Development Division, Molecular and Cell Biology Department, University of California, Berkeley, California, USA
| | - Walter E Finkbeiner
- Department of Pathology, University of California, San Francisco, California, USA
| | - Peter Walentek
- Genetics, Genomics and Development Division, Molecular and Cell Biology Department, University of California, Berkeley, California, .,Renal Division, Department of Medicine, University Freiburg Medical Center and ZBSA - Center for Systems Biological Analysis, Freiburg, .,Spemann Graduate School of Biology and Medicine, Albert Ludwigs University Freiburg, Freiburg,
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38
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Annexin A6 regulates catabolic events in articular chondrocytes via the modulation of NF-κB and Wnt/ß-catenin signaling. PLoS One 2018; 13:e0197690. [PMID: 29771996 PMCID: PMC5957413 DOI: 10.1371/journal.pone.0197690] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 05/07/2018] [Indexed: 12/22/2022] Open
Abstract
Annexin A6 (AnxA6) is expressed in articular chondrocytes at levels higher than in other mesenchymal cell types. However, the role of AnxA6 in articular chondrocytes is not known. Here we show that complete lack of AnxA6 functions resulted in increased ß-catenin activation in Wnt3a-treated murine articular chondrocytes, whereas AnxA6 expressing articular chondrocytes showed decreased ß-catenin activation. High expression of AnxA6 in human articular chondrocytes showed the highest inhibition of Wnt/ß-catenin signaling. Inhibition of Wnt/ß-catenin signaling activity by AnxA6 together with cytosolic Ca2+ was achieved by interfering with the plasma membrane association of the Wnt signaling complex. AnxA6 also affected the cross-talk between Wnt/ß-catenin signaling and NF-κB signaling by decreasing ß-catenin activity and increasing NF-κB activity in Wnt3a-, interleukin-1beta (IL-1ß)-, and combined Wnt3a/IL-1ß-treated cells. Wnt3a treatment increased the mRNA levels of catabolic markers (cyclooxygenase-2, interleukin-6, inducible nitric oxide synthase) to a much lesser degree than IL-1ß treatment in human articular chondrocytes, and decreased the mRNA levels of matrix metalloproteinase-13 (MMP-13) and articular cartilage markers (aggrecan, type II collagen). Furthermore, Wnt3a decreased the mRNA levels of catabolic markers and MMP-13 in IL-1ß-treated human articular chondrocytes. High expression of AnxA6 resulted in decreased mRNA levels of catabolic markers, and increased MMP-13 and articular cartilage marker mRNA levels in Wnt3a-treated human articular chondrocytes, whereas leading to increased mRNA levels of catabolic markers and MMP-13 in human articular chondrocytes treated with IL-1ß, or combined Wnt3a and IL-1ß. Our findings define a novel role for AnxA6 in articular chondrocytes via its modulation of Wnt/ß-catenin and NF-κB signaling activities and the cross-talk between these two signaling pathways.
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Angelova MI, Bitbol AF, Seigneuret M, Staneva G, Kodama A, Sakuma Y, Kawakatsu T, Imai M, Puff N. pH sensing by lipids in membranes: The fundamentals of pH-driven migration, polarization and deformations of lipid bilayer assemblies. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:2042-2063. [PMID: 29501601 DOI: 10.1016/j.bbamem.2018.02.026] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 02/22/2018] [Accepted: 02/24/2018] [Indexed: 01/27/2023]
Abstract
Most biological molecules contain acido-basic groups that modulate their structure and interactions. A consequence is that pH gradients, local heterogeneities and dynamic variations are used by cells and organisms to drive or regulate specific biological functions including energetic metabolism, vesicular traffic, migration and spatial patterning of tissues in development. While the direct or regulatory role of pH in protein function is well documented, the role of hydrogen and hydroxyl ions in modulating the properties of lipid assemblies such as bilayer membranes is only beginning to be understood. Here, we review approaches using artificial lipid vesicles that have been instrumental in providing an understanding of the influence of pH gradients and local variations on membrane vectorial motional processes: migration, membrane curvature effects promoting global or local deformations, crowding generation by segregative polarization processes. In the case of pH induced local deformations, an extensive theoretical framework is given and an application to a specific biological issue, namely the structure and stability of mitochondrial cristae, is described. This article is part of a Special Issue entitled: Emergence of Complex Behavior in Biomembranes edited by Marjorie Longo.
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Affiliation(s)
- Miglena I Angelova
- Sorbonne University, Faculty of Science and Engineering, UFR 925 Physics, Paris F-75005, France; University Paris Diderot - Paris 7, Sorbonne Paris Cité, Laboratory Matière et Systèmes Complexes (MSC) UMR 7057 CNRS, Paris F-75013, France.
| | - Anne-Florence Bitbol
- Sorbonne University, Faculty of Science and Engineering, Laboratory Jean Perrin, UMR 8237 CNRS, Paris F-75005, France
| | - Michel Seigneuret
- University Paris Diderot - Paris 7, Sorbonne Paris Cité, Laboratory Matière et Systèmes Complexes (MSC) UMR 7057 CNRS, Paris F-75013, France
| | - Galya Staneva
- Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Atsuji Kodama
- Department of Physics, Tohoku University, Aoba, Sendai 980-8578, Japan
| | - Yuka Sakuma
- Department of Physics, Tohoku University, Aoba, Sendai 980-8578, Japan
| | | | - Masayuki Imai
- Department of Physics, Tohoku University, Aoba, Sendai 980-8578, Japan
| | - Nicolas Puff
- Sorbonne University, Faculty of Science and Engineering, UFR 925 Physics, Paris F-75005, France; University Paris Diderot - Paris 7, Sorbonne Paris Cité, Laboratory Matière et Systèmes Complexes (MSC) UMR 7057 CNRS, Paris F-75013, France
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40
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Xie Z, Khair M, Shaukat I, Netter P, Mainard D, Barré L, Ouzzine M. Non-canonical Wnt induces chondrocyte de-differentiation through Frizzled 6 and DVL-2/B-raf/CaMKIIα/syndecan 4 axis. Cell Death Differ 2018; 25:1442-1456. [PMID: 29352270 DOI: 10.1038/s41418-017-0050-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 11/20/2017] [Accepted: 11/29/2017] [Indexed: 01/22/2023] Open
Abstract
Dysregulation of Wnt signaling has been implicated in developmental defects and in the pathogenesis of many diseases such as osteoarthritis; however, the underlying mechanisms are poorly understood. Here, we report that non-canonical Wnt signaling induced loss of chondrocyte phenotype through activation of Fz-6/DVL-2/SYND4/CaMKIIα/B-raf/ERK1/2 cascade. We show that in response to Wnt-3a, Frizzled 6 (Fz-6) triggers the docking of CaMKIIα to syndecan 4 (SYND4) and that of B-raf to DVL-2, leading to the phosphorylation of B-raf by CaMKIIα and activation of extracellular signal-regulated kinase 1 and 2 (ERK1/2) signaling, which leads to chondrocyte de-differentiation. We demonstrate that CaMKIIα associates and phosphorylates B-raf in vitro and in vivo. Our study reveals the mechanism by which non-canonical Wnt activates ERK1/2 signaling that induces loss of chondrocyte phenotype, and demonstrates a direct functional relationship between CaMKIIα and B-raf during chondrocyte de-differentiation. The identification of Fz-6, SYND4, and B-raf as novel physiological regulators of chondrocyte phenotype may provide new potential anti-osteoarthritic targets.
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Affiliation(s)
- Zhe Xie
- UMR7365 CNRS-University of Lorraine, Biopôle, Faculty of Medicine, 54505, Vandoeuvre-lès-Nancy, France
| | - Mostafa Khair
- UMR7365 CNRS-University of Lorraine, Biopôle, Faculty of Medicine, 54505, Vandoeuvre-lès-Nancy, France
| | - Irfan Shaukat
- UMR7365 CNRS-University of Lorraine, Biopôle, Faculty of Medicine, 54505, Vandoeuvre-lès-Nancy, France
| | - Patrick Netter
- UMR7365 CNRS-University of Lorraine, Biopôle, Faculty of Medicine, 54505, Vandoeuvre-lès-Nancy, France
| | - Didier Mainard
- UMR7365 CNRS-University of Lorraine, Biopôle, Faculty of Medicine, 54505, Vandoeuvre-lès-Nancy, France
| | - Lydia Barré
- UMR7365 CNRS-University of Lorraine, Biopôle, Faculty of Medicine, 54505, Vandoeuvre-lès-Nancy, France
| | - Mohamed Ouzzine
- UMR7365 CNRS-University of Lorraine, Biopôle, Faculty of Medicine, 54505, Vandoeuvre-lès-Nancy, France.
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Strubberg AM, Liu J, Walker NM, Stefanski CD, MacLeod RJ, Magness ST, Clarke LL. Cftr Modulates Wnt/β-Catenin Signaling and Stem Cell Proliferation in Murine Intestine. Cell Mol Gastroenterol Hepatol 2017; 5:253-271. [PMID: 29675451 PMCID: PMC5904038 DOI: 10.1016/j.jcmgh.2017.11.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 11/18/2017] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Cystic fibrosis (CF) patients and CF mouse models have increased risk for gastrointestinal tumors. CF mice show augmented intestinal proliferation of unknown etiology and an altered intestinal environment. We examined the role of the cystic fibrosis transmembrane conductance regulator (Cftr) in Wnt/β-catenin signaling, stem cell proliferation, and its functional expression in the active intestinal stem cell (ISC) population. Dysregulation of intracellular pH (pHi) in CF ISCs was investigated for facilitation of Wnt/β-catenin signaling. METHODS Crypt epithelia from wild-type (WT) and CF mice were compared ex vivo and in intestinal organoids (enteroids) for proliferation and Wnt/β-catenin signaling by standard assays. Cftr in ISCs was assessed by immunoblot of sorted Sox9 enhanced green fluorescent protein(EGFP) intestinal epithelia and pHi regulation by confocal microfluorimetry of leucine-rich G-protein-coupled receptor 5 ISCs. Plasma membrane association of the Wnt transducer Dishevelled 2 (Dvl2) was assessed by fluorescence imaging of live enteroids from WT and CF mice crossed with Dvl2-EGFP/ACTB-tdTomato,-EGFP)Luo/J (RosamT/mG) mice. RESULTS Relative to WT, CF intestinal crypts showed an ∼30% increase in epithelial and Lgr5+ ISC proliferation and increased Wnt/β-catenin signaling. Cftr was expressed in Sox9EGFPLo ISCs and loss of Cftr induced an alkaline pHi in ISCs. CF crypt-base columnar cells showed a generalized increase in plasma membrane Dvl2-EGFP association as compared with WT. Dvl2-EGFP membrane association was charge- and pH-dependent and increased in WT crypt-base columnar cells by Cftr inhibition. CONCLUSIONS CF intestine shows increased ISC proliferation and Wnt/β-catenin signaling. Loss of Cftr increases pHi in ISCs, which stabilizes the plasma membrane association of the Wnt transducer Dvl, likely facilitating Wnt/β-catenin signaling. Absence of Cftr-dependent suppression of ISC proliferation in the CF intestine may contribute to increased risk for intestinal tumors.
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Key Words
- CBC, crypt-base columnar cell
- CCH, carbachol
- CF, cystic fibrosis
- Cftr, cystic fibrosis transmembrane conductance regulator
- Cystic Fibrosis
- DEP, Dishevelled, Egl-10, and Pleckstrin
- Dishevelled
- Dvl, Dishevelled
- EGFP, enhanced green fluorescent protein
- EdU, 5-ethynyl-2’-deoxyuridine
- Fz, Frizzled
- GI, gastrointestinal
- ISC, intestinal stem cell
- Intracellular pH
- KO, knockout
- Lgr5, leucine-rich G-protein–coupled receptor 5
- Neoplasia
- Organoids
- PBS, phosphate-buffered saline
- PDZ, Post synaptic density protein, Drosophila disc large tumor suppressor, and Zonula occludens-1 protein
- PH3, phospho-histone H3
- ROI, region of interest
- WT, wild type
- pHi, intracellular pH
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Affiliation(s)
- Ashlee M. Strubberg
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri
| | - Jinghua Liu
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Nancy M. Walker
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Casey D. Stefanski
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri
| | - R. John MacLeod
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, Ontario, Canada
| | - Scott T. Magness
- Department of Medicine, Department of Cell and Molecular Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Lane L. Clarke
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri,Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri,Correspondence Address correspondence to: Lane L. Clarke, DVM, PhD, 324D Dalton Cardiovascular Research Center, University of Missouri, 134 Research Park Drive, Columbia, Missouri 65211-3300. fax: (573) 884–4232.
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42
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Strutt H, Gamage J, Strutt D. Robust Asymmetric Localization of Planar Polarity Proteins Is Associated with Organization into Signalosome-like Domains of Variable Stoichiometry. Cell Rep 2017; 17:2660-2671. [PMID: 27926869 PMCID: PMC5177602 DOI: 10.1016/j.celrep.2016.11.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 09/21/2016] [Accepted: 11/02/2016] [Indexed: 11/18/2022] Open
Abstract
In developing epithelia, the core planar polarity proteins physically interact with each other and localize asymmetrically at opposite cell ends, forming intercellular complexes that link the polarity of neighboring cells. Using quantitative imaging to examine the composition of the core protein complex in vivo, we find that complex composition is unexpectedly plastic. The transmembrane proteins Frizzled and Flamingo form a stoichiometric nucleus in the complex, while the relative levels of the other four core proteins can vary independently. Exploring the functional consequences of this, we show that robust cell polarization is achieved over a range of complex stoichiometries but is dependent on maintaining appropriate levels of the components Frizzled and Strabismus. We propose that the core proteins assemble into signalosome-like structures, where stable association is not dependent on one-to-one interactions with binding partners, and signaling functions can act over a wide range of complex compositions.
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Affiliation(s)
- Helen Strutt
- Bateson Centre, Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Jessica Gamage
- Bateson Centre, Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - David Strutt
- Bateson Centre, Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK.
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43
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Tatapudy S, Aloisio F, Barber D, Nystul T. Cell fate decisions: emerging roles for metabolic signals and cell morphology. EMBO Rep 2017; 18:2105-2118. [PMID: 29158350 DOI: 10.15252/embr.201744816] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 09/14/2017] [Accepted: 10/24/2017] [Indexed: 12/25/2022] Open
Abstract
Understanding how cell fate decisions are regulated is a fundamental goal of developmental and stem cell biology. Most studies on the control of cell fate decisions address the contributions of changes in transcriptional programming, epigenetic modifications, and biochemical differentiation cues. However, recent studies have found that other aspects of cell biology also make important contributions to regulating cell fate decisions. These cues can have a permissive or instructive role and are integrated into the larger network of signaling, functioning both upstream and downstream of developmental signaling pathways. Here, we summarize recent insights into how cell fate decisions are influenced by four aspects of cell biology: metabolism, reactive oxygen species (ROS), intracellular pH (pHi), and cell morphology. For each topic, we discuss how these cell biological cues interact with each other and with protein-based mechanisms for changing gene transcription. In addition, we highlight several questions that remain unanswered in these exciting and relatively new areas of the field.
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Affiliation(s)
- Sumitra Tatapudy
- Departments of Anatomy and OB-GYN/RS, University of California, San Francisco, San Francisco, CA, USA
| | - Francesca Aloisio
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
| | - Diane Barber
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA, USA
| | - Todd Nystul
- Departments of Anatomy and OB-GYN/RS, University of California, San Francisco, San Francisco, CA, USA
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44
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Finkielstein CV, Capelluto DGS. Disabled-2: A modular scaffold protein with multifaceted functions in signaling. Bioessays 2017; 38 Suppl 1:S45-55. [PMID: 27417122 DOI: 10.1002/bies.201670907] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 07/08/2015] [Accepted: 07/12/2015] [Indexed: 12/14/2022]
Abstract
Disabled-2 (Dab2) is a multimodular scaffold protein with signaling roles in the domains of cell growth, trafficking, differentiation, and homeostasis. Emerging evidences place Dab2 as a novel modulator of cell-cell interaction; however, its mode of action has remained largely elusive. In this review, we highlight the relevance of Dab2 function in cell signaling and development and provide the most recent and comprehensive analysis of Dab2's action as a mediator of homotypical and heterotypical interactions. Accordingly, Dab-2 controls the extent of platelet aggregation through various motifs within its N-terminus. Dab2 interacts with the cytosolic tail of the integrin receptor blocking inside-out signaling, whereas extracellular Dab2 competes with fibrinogen for integrin αIIb β3 receptor binding and, thus, modulates outside-in signaling. An additional level of regulation results from Dab2's association with cell surface lipids, an event that defines the extent of cell-cell interactions. As a multifaceted regulator, Dab2 acts as a mediator of endocytosis through its association with the [FY]xNPx[YF] motifs of internalized cell surface receptors, phosphoinositides, and clathrin. Other emerging roles of Dab2 include its participation in developmental mechanisms required for tissue formation and in modulation of immune responses. This review highlights the various novel mechanisms by which Dab2 mediates an array of signaling events with vast physiological consequences.
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Affiliation(s)
- Carla V Finkielstein
- Integrated Cellular Responses Laboratory, Department of Biological Sciences, Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA, USA
| | - Daniel G S Capelluto
- Protein Signaling Domains Laboratory, Department of Biological Sciences, Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA, USA
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45
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Strakova K, Matricon P, Yokota C, Arthofer E, Bernatik O, Rodriguez D, Arenas E, Carlsson J, Bryja V, Schulte G. The tyrosine Y250 2.39 in Frizzled 4 defines a conserved motif important for structural integrity of the receptor and recruitment of Disheveled. Cell Signal 2017; 38:85-96. [DOI: 10.1016/j.cellsig.2017.06.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 06/09/2017] [Accepted: 06/26/2017] [Indexed: 12/16/2022]
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46
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Wald JH, Hatakeyama J, Printsev I, Cuevas A, Fry WH, Saldana MJ, Vorst KV, Rowson-Hodel A, Angelastro JM, Sweeney C, Carraway KL. Suppression of planar cell polarity signaling and migration in glioblastoma by Nrdp1-mediated Dvl polyubiquitination. Oncogene 2017; 36:5158-5167. [PMID: 28481871 PMCID: PMC5589482 DOI: 10.1038/onc.2017.126] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 02/15/2017] [Accepted: 03/23/2017] [Indexed: 12/16/2022]
Abstract
The lethality of the aggressive brain tumor glioblastoma multiforme (GBM) results in part from its strong propensity to invade surrounding normal brain tissue. Although oncogenic drivers such as epidermal growth factor receptor activation and Phosphatase and Tensin homolog inactivation are thought to promote the motility and invasiveness of GBM cells via phosphatidylinostitol 3-kinase activation, other unexplored mechanisms may also contribute to malignancy. Here we demonstrate that several components of the planar cell polarity (PCP) arm of non-canonical Wnt signaling including VANGL1, VANGL2 and FZD7 are transcriptionally upregulated in glioma and correlate with poorer patient outcome. Knockdown of the core PCP pathway component VANGL1 suppresses the motility of GBM cell lines, pointing to an important mechanistic role for this pathway in glioblastoma malignancy. We further observe that restoration of Nrdp1, a RING finger type E3 ubiquitin ligase whose suppression in GBM also correlates with poor prognosis, reduces GBM cell migration and invasiveness by suppressing PCP signaling. Our observations indicate that Nrdp1 physically interacts with the Vangl1 and Vangl2 proteins to mediate the K63-linked polyubiquitination of the Dishevelled, Egl-10 and Pleckstrin (DEP) domain of the Wnt pathway protein Dishevelled (Dvl). Ubiquitination hinders Dvl binding to phosphatidic acid, an interaction necessary for efficient Dvl recruitment to the plasma membrane upon Wnt stimulation of Fzd receptor and for the propagation of downstream signals. We conclude that the PCP pathway contributes significantly to the motility and hence the invasiveness of GBM cells, and that Nrdp1 acts as a negative regulator of PCP signaling by inhibiting Dvl through a novel polyubiquitination mechanism. We propose that the upregulation of core PCP components, together with the loss of the key negative regulator Nrdp1, act coordinately to promote GBM invasiveness and malignancy.
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Affiliation(s)
- Jessica H. Wald
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, University of California Davis School of Medicine, Sacramento, CA, USA
| | - Jason Hatakeyama
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, University of California Davis School of Medicine, Sacramento, CA, USA
| | - Ignat Printsev
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, University of California Davis School of Medicine, Sacramento, CA, USA
| | - Antonio Cuevas
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, University of California Davis School of Medicine, Sacramento, CA, USA
| | - William H.D. Fry
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, University of California Davis School of Medicine, Sacramento, CA, USA
| | - Matthew J. Saldana
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, University of California Davis School of Medicine, Sacramento, CA, USA
| | - Kacey Vander Vorst
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, University of California Davis School of Medicine, Sacramento, CA, USA
| | - Ashley Rowson-Hodel
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, University of California Davis School of Medicine, Sacramento, CA, USA
| | - James M. Angelastro
- Department of Molecular Biosciences, University of California Davis School of Veterinary Medicine, Davis, CA, USA
| | - Colleen Sweeney
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, University of California Davis School of Medicine, Sacramento, CA, USA
| | - Kermit L. Carraway
- Department of Biochemistry and Molecular Medicine, and UC Davis Comprehensive Cancer Center, University of California Davis School of Medicine, Sacramento, CA, USA
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47
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The N-Terminal Part of the Dishevelled DEP Domain Is Required for Wnt/β-Catenin Signaling in Mammalian Cells. Mol Cell Biol 2017; 37:MCB.00145-17. [PMID: 28674183 PMCID: PMC5574038 DOI: 10.1128/mcb.00145-17] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/15/2017] [Indexed: 12/27/2022] Open
Abstract
Dishevelled (DVL) proteins are key mediators of the Wnt/β-catenin signaling pathway. All DVL proteins contain three conserved domains: DIX, PDZ, and DEP. There is a consensus in the field that the DIX domain is critical for Wnt/β-catenin signaling, but contradictory evidence regarding the function of the DEP domain exists. It has been difficult, until recently, to test the importance of the DEP domain rigorously because of the interference with endogenous DVL, expressed in all Wnt-responsive cell lines. In this study, we took advantage of DVL knockout (DVL1/DVL2/DVL3 triple knockout) cells fully deficient in Wnt3a-induced signaling events and performed a series of rescue experiments. Using these complementation assays, we analyzed the role of individual DVL isoforms. Further domain mapping of DVL1 showed that both the DVL1 DEP domain and especially its N-terminal region are required and sufficient for Wnt3a-induced phosphorylation of LRP6 and TopFlash reporter activation. On the contrary, multiple DEP domain mutants deficient in the planar cell polarity (PCP) pathway could fully rescue the Wnt3a response. This study provides conclusive evidence that the DVL DEP domain is essential for Wnt/β-catenin signaling in mammalian cells and establishes an experimental system suitable for further functional testing of DVL.
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48
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Membrane Targeting of Disheveled Can Bypass the Need for Arrow/LRP5. Sci Rep 2017; 7:6934. [PMID: 28761148 PMCID: PMC5537288 DOI: 10.1038/s41598-017-04414-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2017] [Accepted: 05/15/2017] [Indexed: 12/03/2022] Open
Abstract
The highly conserved Wnt signaling pathway regulates cell proliferation and differentiation in vertebrates and invertebrates. Upon binding of a Wnt ligand to a receptor of the Fz family, Disheveled (Dsh/Dvl) transduces the signal during canonical and non-canonical Wnt signaling. The specific details of how this process occurs have proven difficult to study, especially as Dsh appears to function as a switch between different branches of Wnt signaling. Here we focus on the membrane-proximal events that occur once Dsh is recruited to the membrane. We show that membrane-tethering of the Dsh protein is sufficient to induce canonical Wnt signaling activation even in the absence of the Wnt co-receptor Arrow/LRP5/6. We map the protein domains required for pathway activation in membrane tethered constructs finding that both the DEP and PDZ domains are dispensable for canonical signaling only in membrane-tethered Dsh, but not in untethered/normal Dsh. These data lead to a signal activation model, where Arrow is required to localize Dsh to the membrane during canonical Wnt signaling placing Dsh downstream of Arrow.
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49
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Comparative proteome analysis of the hepatopancreas from the Pacific white shrimp Litopenaeus vannamei under long-term low salinity stress. J Proteomics 2017; 162:1-10. [DOI: 10.1016/j.jprot.2017.04.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Revised: 12/09/2016] [Accepted: 04/04/2017] [Indexed: 01/12/2023]
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50
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Ulmschneider B, Grillo-Hill BK, Benitez M, Azimova DR, Barber DL, Nystul TG. Increased intracellular pH is necessary for adult epithelial and embryonic stem cell differentiation. J Cell Biol 2017; 215:345-355. [PMID: 27821494 PMCID: PMC5100294 DOI: 10.1083/jcb.201606042] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Revised: 08/18/2016] [Accepted: 10/05/2016] [Indexed: 12/19/2022] Open
Abstract
Despite extensive knowledge about the transcriptional regulation of stem cell differentiation, less is known about the role of dynamic cytosolic cues. We report that an increase in intracellular pH (pHi) is necessary for the efficient differentiation of Drosophila adult follicle stem cells (FSCs) and mouse embryonic stem cells (mESCs). We show that pHi increases with differentiation from FSCs to prefollicle cells (pFCs) and follicle cells. Loss of the Drosophila Na+-H+ exchanger DNhe2 lowers pHi in differentiating cells, impairs pFC differentiation, disrupts germarium morphology, and decreases fecundity. In contrast, increasing pHi promotes excess pFC cell differentiation toward a polar/stalk cell fate through suppressing Hedgehog pathway activity. Increased pHi also occurs with mESC differentiation and, when prevented, attenuates spontaneous differentiation of naive cells, as determined by expression of microRNA clusters and stage-specific markers. Our findings reveal a previously unrecognized role of pHi dynamics for the differentiation of two distinct types of stem cell lineages, which opens new directions for understanding conserved regulatory mechanisms.
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Affiliation(s)
- Bryne Ulmschneider
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143.,Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, San Francisco, CA 94143
| | - Bree K Grillo-Hill
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143.,Department of Biological Sciences, San Jose State University, San Jose, CA 95192
| | - Marimar Benitez
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143.,Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, San Francisco, CA 94143
| | - Dinara R Azimova
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143.,Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, San Francisco, CA 94143
| | - Diane L Barber
- Department of Cell and Tissue Biology, University of California, San Francisco, San Francisco, CA 94143
| | - Todd G Nystul
- Department of Anatomy, University of California, San Francisco, San Francisco, CA 94143 .,Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, San Francisco, CA 94143
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