1
|
Vue Z, Garza‐Lopez E, Neikirk K, Katti P, Vang L, Beasley H, Shao J, Marshall AG, Crabtree A, Murphy AC, Jenkins BC, Prasad P, Evans C, Taylor B, Mungai M, Killion M, Stephens D, Christensen TA, Lam J, Rodriguez B, Phillips MA, Daneshgar N, Koh H, Koh A, Davis J, Devine N, Saleem M, Scudese E, Arnold KR, Vanessa Chavarin V, Daniel Robinson R, Chakraborty M, Gaddy JA, Sweetwyne MT, Wilson G, Zaganjor E, Kezos J, Dondi C, Reddy AK, Glancy B, Kirabo A, Quintana AM, Dai D, Ocorr K, Murray SA, Damo SM, Exil V, Riggs B, Mobley BC, Gomez JA, McReynolds MR, Hinton A. 3D reconstruction of murine mitochondria reveals changes in structure during aging linked to the MICOS complex. Aging Cell 2023; 22:e14009. [PMID: 37960952 PMCID: PMC10726809 DOI: 10.1111/acel.14009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 09/01/2023] [Accepted: 09/19/2023] [Indexed: 11/15/2023] Open
Abstract
During aging, muscle gradually undergoes sarcopenia, the loss of function associated with loss of mass, strength, endurance, and oxidative capacity. However, the 3D structural alterations of mitochondria associated with aging in skeletal muscle and cardiac tissues are not well described. Although mitochondrial aging is associated with decreased mitochondrial capacity, the genes responsible for the morphological changes in mitochondria during aging are poorly characterized. We measured changes in mitochondrial morphology in aged murine gastrocnemius, soleus, and cardiac tissues using serial block-face scanning electron microscopy and 3D reconstructions. We also used reverse transcriptase-quantitative PCR, transmission electron microscopy quantification, Seahorse analysis, and metabolomics and lipidomics to measure changes in mitochondrial morphology and function after loss of mitochondria contact site and cristae organizing system (MICOS) complex genes, Chchd3, Chchd6, and Mitofilin. We identified significant changes in mitochondrial size in aged murine gastrocnemius, soleus, and cardiac tissues. We found that both age-related loss of the MICOS complex and knockouts of MICOS genes in mice altered mitochondrial morphology. Given the critical role of mitochondria in maintaining cellular metabolism, we characterized the metabolomes and lipidomes of young and aged mouse tissues, which showed profound alterations consistent with changes in membrane integrity, supporting our observations of age-related changes in muscle tissues. We found a relationship between changes in the MICOS complex and aging. Thus, it is important to understand the mechanisms that underlie the tissue-dependent 3D mitochondrial phenotypic changes that occur in aging and the evolutionary conservation of these mechanisms between Drosophila and mammals.
Collapse
Affiliation(s)
- Zer Vue
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
| | | | - Kit Neikirk
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
| | - Prasanna Katti
- National Heart, Lung and Blood Institute, National Institutes of HealthMarylandBethesdaUSA
| | - Larry Vang
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
| | - Heather Beasley
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
| | - Jianqiang Shao
- Central Microscopy Research FacilityUniversity of IowaIowaIowa CityUSA
| | - Andrea G. Marshall
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
| | - Amber Crabtree
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
| | - Alexandria C. Murphy
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life SciencesPennsylvania State UniversityPennsylvaniaState CollegeUSA
| | - Brenita C. Jenkins
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life SciencesPennsylvania State UniversityPennsylvaniaState CollegeUSA
| | - Praveena Prasad
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life SciencesPennsylvania State UniversityPennsylvaniaState CollegeUSA
| | - Chantell Evans
- Department of Cell BiologyDuke University School of MedicineNorth CarolinaDurhamUSA
| | - Brittany Taylor
- J. Crayton Pruitt Family Department of Biomedical EngineeringUniversity of FloridaFloridaGainesvilleUSA
| | - Margaret Mungai
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
| | - Mason Killion
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
| | - Dominique Stephens
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
| | | | - Jacob Lam
- Department of Internal MedicineUniversity of IowaIowaIowa CityUSA
| | | | - Mark A. Phillips
- Department of Integrative BiologyOregon State UniversityOregonCorvallisUSA
| | - Nastaran Daneshgar
- Department of Integrative BiologyOregon State UniversityOregonCorvallisUSA
| | - Ho‐Jin Koh
- Department of Biological SciencesTennessee State UniversityTennesseeNashvilleUSA
| | - Alice Koh
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
- Department of MedicineVanderbilt University Medical CenterTennesseeNashvilleUSA
| | - Jamaine Davis
- Department of Biochemistry, Cancer Biology, Neuroscience, and PharmacologyMeharry Medical CollegeTennesseeNashvilleUSA
| | - Nina Devine
- Department of Integrative BiologyOregon State UniversityOregonCorvallisUSA
| | - Mohammad Saleem
- Department of MedicineVanderbilt University Medical CenterTennesseeNashvilleUSA
| | - Estevão Scudese
- Laboratory of Biosciences of Human Motricity (LABIMH) of the Federal University of State of Rio de Janeiro (UNIRIO)Rio de JaneiroBrazil
- Sport Sciences and Exercise Laboratory (LaCEE)Catholic University of Petrópolis (UCP)PetrópolisState of Rio de JaneiroBrazil
| | - Kenneth Ryan Arnold
- Department of Ecology and Evolutionary BiologyUniversity of California at IrvineCaliforniaIrvineUSA
| | - Valeria Vanessa Chavarin
- Department of Ecology and Evolutionary BiologyUniversity of California at IrvineCaliforniaIrvineUSA
| | - Ryan Daniel Robinson
- Department of Ecology and Evolutionary BiologyUniversity of California at IrvineCaliforniaIrvineUSA
| | | | - Jennifer A. Gaddy
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
- Department of MedicineVanderbilt University Medical CenterTennesseeNashvilleUSA
- Department of Medicine Health and SocietyVanderbilt UniversityTennesseeNashvilleUSA
- Department of Pathology, Microbiology and ImmunologyVanderbilt University Medical CenterTennesseeNashvilleUSA
- Department of Veterans AffairsTennessee Valley Healthcare SystemsTennesseeNashvilleUSA
| | - Mariya T. Sweetwyne
- Department of Laboratory Medicine and PathologyUniversity of WashingtonWashingtonSeattleUSA
| | - Genesis Wilson
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
| | - Elma Zaganjor
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
| | - James Kezos
- Sanford Burnham Prebys Medical Discovery InstituteCaliforniaLa JollaUSA
| | - Cristiana Dondi
- Sanford Burnham Prebys Medical Discovery InstituteCaliforniaLa JollaUSA
| | | | - Brian Glancy
- National Heart, Lung and Blood Institute, National Institutes of HealthMarylandBethesdaUSA
- National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of HealthMarylandBethesdaUSA
| | - Annet Kirabo
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
- Department of MedicineVanderbilt University Medical CenterTennesseeNashvilleUSA
| | - Anita M. Quintana
- Department of Biological Sciences, Border Biomedical Research CenterUniversity of Texas at El PasoTexasEl PasoUSA
| | - Dao‐Fu Dai
- Department of PathologyUniversity of Johns Hopkins School of MedicineMarylandBaltimoreUSA
| | - Karen Ocorr
- Sanford Burnham Prebys Medical Discovery InstituteCaliforniaLa JollaUSA
| | - Sandra A. Murray
- Department of Cell Biology, School of MedicineUniversity of PittsburghPennsylvaniaPittsburghUSA
| | - Steven M. Damo
- Department of Life and Physical SciencesFisk UniversityTennesseeNashvilleUSA
- Center for Structural BiologyVanderbilt UniversityTennesseeNashvilleUSA
| | - Vernat Exil
- Department of Pediatrics, Carver College of MedicineUniversity of IowaIowaIowa CityUSA
- Department of Pediatrics, Division of CardiologySt. Louis University School of MedicineMissouriSt. LouisUSA
| | - Blake Riggs
- Department of BiologySan Francisco State UniversityCaliforniaSan FranciscoUSA
| | - Bret C. Mobley
- Department of PathologyVanderbilt University Medical CenterTennesseeNashvilleUSA
| | - Jose A. Gomez
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
- Department of MedicineVanderbilt University Medical CenterTennesseeNashvilleUSA
| | - Melanie R. McReynolds
- Department of Biochemistry and Molecular Biology, The Huck Institute of the Life SciencesPennsylvania State UniversityPennsylvaniaState CollegeUSA
| | - Antentor Hinton
- Department of Molecular Physiology and BiophysicsVanderbilt UniversityTennesseeNashvilleUSA
| |
Collapse
|
2
|
Vue Z, Neikirk K, Vang L, Garza-Lopez E, Christensen TA, Shao J, Lam J, Beasley HK, Marshall AG, Crabtree A, Anudokem J, Rodriguez B, Kirk B, Bacevac S, Barongan T, Shao B, Stephens DC, Kabugi K, Koh HJ, Koh A, Evans CS, Taylor B, Reddy AK, Miller-Fleming T, Actkins KV, Zaganjor E, Daneshgar N, Murray SA, Mobley BC, Damo SM, Gaddy JA, Riggs B, Wanjalla C, Kirabo A, McReynolds M, Gomez JA, Phillips MA, Exil V, Dai DF, Hinton A. Three-dimensional mitochondria reconstructions of murine cardiac muscle changes in size across aging. Am J Physiol Heart Circ Physiol 2023; 325:H965-H982. [PMID: 37624101 PMCID: PMC10977873 DOI: 10.1152/ajpheart.00202.2023] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 07/26/2023] [Accepted: 08/12/2023] [Indexed: 08/26/2023]
Abstract
With sparse treatment options, cardiac disease remains a significant cause of death among humans. As a person ages, mitochondria breakdown and the heart becomes less efficient. Heart failure is linked to many mitochondria-associated processes, including endoplasmic reticulum stress, mitochondrial bioenergetics, insulin signaling, autophagy, and oxidative stress. The roles of key mitochondrial complexes that dictate the ultrastructure, such as the mitochondrial contact site and cristae organizing system (MICOS), in aging cardiac muscle are poorly understood. To better understand the cause of age-related alteration in mitochondrial structure in cardiac muscle, we used transmission electron microscopy (TEM) and serial block facing-scanning electron microscopy (SBF-SEM) to quantitatively analyze the three-dimensional (3-D) networks in cardiac muscle samples of male mice at aging intervals of 3 mo, 1 yr, and 2 yr. Here, we present the loss of cristae morphology, the inner folds of the mitochondria, across age. In conjunction with this, the three-dimensional (3-D) volume of mitochondria decreased. These findings mimicked observed phenotypes in murine cardiac fibroblasts with CRISPR/Cas9 knockout of Mitofilin, Chchd3, Chchd6 (some members of the MICOS complex), and Opa1, which showed poorer oxidative consumption rate and mitochondria with decreased mitochondrial length and volume. In combination, these data show the need to explore if loss of the MICOS complex in the heart may be involved in age-associated mitochondrial and cristae structural changes.NEW & NOTEWORTHY This article shows how mitochondria in murine cardiac changes, importantly elucidating age-related changes. It also is the first to show that the MICOS complex may play a role in outer membrane mitochondrial structure.
Collapse
Affiliation(s)
- Zer Vue
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Kit Neikirk
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Larry Vang
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Edgar Garza-Lopez
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Trace A Christensen
- Microscopy and Cell Analysis Core Facility, Mayo Clinic, Rochester, Minnesota, United States
| | - Jianqiang Shao
- Central Microscopy Research Facility, University of Iowa, Iowa City, Iowa, United States
| | - Jacob Lam
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Heather K Beasley
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Andrea G Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Amber Crabtree
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Josephs Anudokem
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Benjamin Rodriguez
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Benjamin Kirk
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Serif Bacevac
- Department of Internal Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Taylor Barongan
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Bryanna Shao
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Dominique C Stephens
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
- Department of Life and Physical Sciences, Fisk University, Nashville, Tennessee, United States
| | - Kinuthia Kabugi
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Ho-Jin Koh
- Department of Biological Sciences, Tennessee State University, Nashville, Tennessee, United States
| | - Alice Koh
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Chantell S Evans
- Department of Cell Biology, Duke University School of Medicine, Durham, North Carolina, United States
| | - Brittany Taylor
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida, United States
| | - Anilkumar K Reddy
- Department of Medicine, Baylor College of Medicine, Houston, Texas, United States
| | - Tyne Miller-Fleming
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Ky'Era V Actkins
- Division of Genetic Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Elma Zaganjor
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| | - Nastaran Daneshgar
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Sandra A Murray
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
| | - Bret C Mobley
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Steven M Damo
- Department of Life and Physical Sciences, Fisk University, Nashville, Tennessee, United States
| | - Jennifer A Gaddy
- Department of Pathology, Microbiology and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, United States
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
- Tennessee Valley Healthcare Systems, United States Department of Veterans Affairs, Nashville, Tennessee, United States
| | - Blake Riggs
- Department of Biology at San Francisco State University, San Francisco, California, United States
| | - Celestine Wanjalla
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Annet Kirabo
- Division of Clinical Pharmacology, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Melanie McReynolds
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, State College, Pennsylvania, United States
| | - Jose A Gomez
- Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Mark A Phillips
- Department of Integrative Biology, Oregon State University, Corvallis, Oregon, United States
| | - Vernat Exil
- Division of Cardiology, Department of Pediatrics, St. Louis University School of Medicine, St. Louis, Missouri, United States
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States
| | - Dao-Fu Dai
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, United States
| |
Collapse
|
3
|
Ascencio G, de Cruz MA, Abuel J, Alvarado S, Arriaga Y, Conrad E, Castro A, Eichelberger K, Galvan L, Gundy G, Garcia JAI, Jimenez A, Lu NT, Lugar C, Marania R, Mendsaikhan T, Ortega J, Nand N, Rodrigues NS, Shabazz K, Tam C, Valenciano E, Hayzelden C, Eritano AS, Riggs B. A deficiency screen of the 3rd chromosome for dominant modifiers of the Drosophila ER integral membrane protein, Jagunal. G3 (Bethesda) 2023; 13:jkad059. [PMID: 36932646 PMCID: PMC10320142 DOI: 10.1093/g3journal/jkad059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 02/16/2023] [Accepted: 02/20/2023] [Indexed: 03/19/2023]
Abstract
The mechanism surrounding chromosome inheritance during cell division has been well documented, however, organelle inheritance during mitosis is less understood. Recently, the endoplasmic reticulum (ER) has been shown to reorganize during mitosis, dividing asymmetrically in proneuronal cells prior to cell fate selection, indicating a programmed mechanism of inheritance. ER asymmetric partitioning in proneural cells relies on the highly conserved ER integral membrane protein, Jagunal (Jagn). Knockdown of Jagn in the compound Drosophila eye displays a pleotropic rough eye phenotype in 48% of the progeny. To identify genes involved in Jagn dependent ER partitioning pathway, we performed a dominant modifier screen of the 3rd chromosome for enhancers and suppressors of this Jagn-RNAi-induced rough eye phenotype. We screened through 181 deficiency lines covering the 3L and 3R chromosomes and identified 12 suppressors and 10 enhancers of the Jagn-RNAi phenotype. Based on the functions of the genes covered by the deficiencies, we identified genes that displayed a suppression or enhancement of the Jagn-RNAi phenotype. These include Division Abnormally Delayed (Dally), a heparan sulfate proteoglycan, the γ-secretase subunit Presenilin, and the ER resident protein Sec63. Based on our understanding of the function of these targets, there is a connection between Jagn and the Notch signaling pathway. Further studies will elucidate the role of Jagn and identified interactors within the mechanisms of ER partitioning during mitosis.
Collapse
Affiliation(s)
- Gerson Ascencio
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Matthew A de Cruz
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Judy Abuel
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Sydney Alvarado
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Yuma Arriaga
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Emily Conrad
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Alonso Castro
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Katharine Eichelberger
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Laura Galvan
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Grace Gundy
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | | | - Alyssa Jimenez
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Nhien Tuyet Lu
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Catharine Lugar
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Ronald Marania
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Tserendavaa Mendsaikhan
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Jose Ortega
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Natasha Nand
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Nicole S Rodrigues
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Khayla Shabazz
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Cynnie Tam
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Emmanuel Valenciano
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Clive Hayzelden
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Anthony S Eritano
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| | - Blake Riggs
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 4132, USA
| |
Collapse
|
4
|
Mays A, Byars-Winston A, Hinton A, Marshall AG, Kirabo A, August A, Marlin BJ, Riggs B, Tolbert B, Wanjalla C, Womack C, Evans CS, Barnes C, Starbird C, Williams C, Reynolds C, Taabazuing C, Cameron CE, Murray DD, Applewhite D, Morton DJ, Lee D, Williams DW, Lynch D, Brady D, Lynch E, Rutaganira FUN, Silva GM, Shuler H, Saboor IA, Davis J, Dzirasa K, Hammonds-Odie L, Reyes L, Sweetwyne MT, McReynolds MR, Johnson MDL, Smith NA, Pittman N, Ajijola OA, Smith Q, Robinson RAS, Lewis SC, Murray SA, Black S, Neal SE, Andrisse S, Townsend S, Damo SM, Griffith TN, Lambert WM, Clemons WM. Juneteenth in STEMM and the barriers to equitable science. Cell 2023; 186:2510-2517. [PMID: 37295396 DOI: 10.1016/j.cell.2023.05.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 05/06/2023] [Accepted: 05/12/2023] [Indexed: 06/12/2023]
Abstract
We are 52 Black scientists. Here, we establish the context of Juneteenth in STEMM and discuss the barriers Black scientists face, the struggles they endure, and the lack of recognition they receive. We review racism's history in science and provide institutional-level solutions to reduce the burdens on Black scientists.
Collapse
Affiliation(s)
- Alfred Mays
- Burroughs Wellcome Fund, Durham, NC 27709, USA
| | - Angela Byars-Winston
- Department of Medicine, Institute for Diversity Science, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Antentor Hinton
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA.
| | - Andrea G Marshall
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA
| | - Annet Kirabo
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN 37232, USA; Department of Medicine, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Vanderbilt University, Nashville, TN 37232, USA
| | - Avery August
- Department of Microbiology and Immunology, Cornell University College of Veterinary Medicine, Ithaca, NY 14853, USA
| | - Bianca J Marlin
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Department of Psychology, Columbia University, New York, NY 10032, USA; Department of Neuroscience, Columbia University, New York, NY 10027, USA
| | - Blake Riggs
- Department of Biology, San Francisco State University, San Francisco, CA 94132, USA
| | - Blanton Tolbert
- Department of Chemistry, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Celestine Wanjalla
- Division of Infectious Diseases, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Chad Womack
- National STEM Programs and Tech Initiatives at the education philanthropic charity, UNCF, Washington, DC 20001, USA
| | - Chantell S Evans
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27708, USA
| | | | - Chrystal Starbird
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Clintoria Williams
- Department of Neuroscience, Cell Biology & Physiology, College of Science and Mathematics, Wright State University Boonshoft School of Medicine, Dayton, OH 45435, USA
| | - Corey Reynolds
- Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA; Mouse Phenotyping Core, Baylor College of Medicine, Houston, TX 77030, USA
| | - Cornelius Taabazuing
- Department of Biochemistry and Biophysics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Craig E Cameron
- Department of Microbiology and Immunology, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Debra D Murray
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | | | - Derrick J Morton
- Department of Biological Sciences, University of Southern California Los Angeles, Los Angeles, CA 90089, USA
| | - Dexter Lee
- Department of Physiology and Biophysics, Howard University College of Medicine, Washington, DC 20059, USA
| | - Dionna W Williams
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Donald Lynch
- Department of Medicine, Division of Cardiovascular Health and Disease, University of Cincinnati, Cincinnati, OH, USA
| | - Donita Brady
- Department of Cancer Biology, University of Pennsylvania, Philadelphia, PA 19104, USA; Abramson Family Cancer Research Institute, University of Pennsylvania, Philadelphia, PA 19104, USA; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Erin Lynch
- University of Michigan Health System, Ann Arbor, MI 48109, USA
| | - Florentine U N Rutaganira
- Department of Biochemistry, Stanford University, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA
| | - Gustavo M Silva
- Department of Biology, Duke University, Durham, NC 27708, USA
| | - Haysetta Shuler
- Winston-Salem State University Department of Biological Sciences, Winston-Salem, NC 27110, USA
| | - Ishmail Abdus Saboor
- Mortimer B. Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Department of Biological Sciences, Columbia University, New York, NY 10027, USA.
| | - Jamaine Davis
- Department of Biochemistry, Cancer Biology, Neuroscience, Pharmacology, Meharry Medical College, Nashville, TN 37232, USA; Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA
| | - Kafui Dzirasa
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA; Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC 27710, USA; Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA.
| | - Latanya Hammonds-Odie
- Department of Biological Sciences before School of Science and Technology, Georgia Gwinnett College, Lawrenceville, GA 30043, USA
| | - Loretta Reyes
- Division of Pediatric Nephrology, Emory University School of Medicine, Atlanta, GA 30322, USA
| | - Mariya T Sweetwyne
- Department of Laboratory Medicine and Pathology, University of Washington, Seattle, WA 98195, USA
| | - Melanie R McReynolds
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA 16802, USA; Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA 16802, USA
| | - Michael D L Johnson
- Department of Immunobiology, University of Arizona, Tucson, AZ 85724, USA; BIO5 Institute, University of Arizona, Tucson, AZ 85724, USA; Valley Fever Center for Excellence, University of Arizona, Tucson, AZ, USA
| | - Nathan A Smith
- Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester, School of Medicine and Dentistry, Rochester, NY 14642, USA
| | - Nikea Pittman
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Olujimi A Ajijola
- UCLA Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA 90095, USA
| | - Quinton Smith
- School of Engineering, University of California, Irvine, CA 92697-3975, USA
| | - Renã A S Robinson
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Samantha C Lewis
- Department of Molecular and Cellular Biology, University of California Berkeley, Berkeley, CA 94720, USA
| | - Sandra A Murray
- Department of Cell Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 52013, USA.
| | - Sherilynn Black
- Office of the Provost and Division of Medical Education, Duke University, Durham, NC 27708, USA.
| | - Sonya E Neal
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, USA
| | - Stanley Andrisse
- Department of Physiology and Biophysics, Howard University College of Medicine, Washington, DC 20059, USA; Department of Pediatrics, School of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA
| | - Steven Townsend
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
| | - Steven M Damo
- Center for Structural Biology, Vanderbilt University, Nashville, TN 37232, USA; Department of Life and Physical Sciences, Fisk University, Nashville, TN 37208, USA.
| | - Theanne N Griffith
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA 95616, USA
| | - W Marcus Lambert
- Department of Epidemiology and Biostatistics, SUNY Downstate Health Sciences University, New York, NY 11203, USA
| | - William M Clemons
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| |
Collapse
|
5
|
Aranda ML, Diaz M, Mena LG, Ortiz JI, Rivera-Nolan C, Sanchez DC, Sanchez MJ, Upchurch AM, Williams CS, Boorstin SN, Cardoso LM, Dominguez M, Elias S, Lopez EE, Ramirez RE, Romero PJ, Tigress FN, Wilson JA, Winstead R, Cantley JT, Chen JC, Fuse M, Goldman MA, Govindan B, Ingmire P, Knight JD, Pasion SG, Pennings PS, Sehgal RNM, de Vera PT, Kelley L, Schinske JN, Riggs B, Burrus LW, Tanner KD. Student-Authored Scientist Spotlights: Investigating the Impacts of Engaging Undergraduates as Developers of Inclusive Curriculum through a Service-Learning Course. CBE Life Sci Educ 2021; 20:ar55. [PMID: 34546103 PMCID: PMC8715779 DOI: 10.1187/cbe.21-03-0060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Scientist Spotlights-curricular materials that employ the personal and professional stories of scientists from diverse backgrounds-have previously been shown to positively influence undergraduate students' relatability to and perceptions of scientists. We hypothesized that engaging students in authoring Scientist Spotlights might produce curricular materials of similar impact, as well as provide a mechanism for student involvement as partners in science education reform. To test this idea and investigate the impact of student-authored Scientist Spotlights, we developed a service-learning course in which teams of biology students partnered with an instructor to develop and implement Scientist Spotlights in a biology course. Results revealed that exposure to three or four student-authored Scientist Spotlights significantly shifted peers' perceptions of scientists in all partner courses. Interestingly, student-authored Scientist Spotlights shifted peers' relatability to scientists similarly among both white students and students of color. Further, student authors themselves showed increases in their relatability to scientists. Finally, a department-wide survey demonstrated significant differences in students' perceptions of scientist representation between courses with and without student-authored Spotlights. Results suggest that engaging students as authors of inclusive curricular materials and partners in reform is a promising approach to promoting inclusion and addressing representation in science.
Collapse
Affiliation(s)
- Maurina L. Aranda
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026
- *Address correspondence to: Maurina L. Aranda ()
| | - Michelle Diaz
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | | | - Jocelyn I. Ortiz
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | | | - Daniela C. Sanchez
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Melissa J. Sanchez
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Allison M. Upchurch
- Department of Biological Sciences, Southern Illinois University Edwardsville, Edwardsville, IL 62026
| | | | | | - Laura M. Cardoso
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Matthew Dominguez
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Sarah Elias
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Elmer E. Lopez
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Ruby E. Ramirez
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Paola Juliet Romero
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | | | | | - Ryan Winstead
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Jason T. Cantley
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Joseph C. Chen
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Megumi Fuse
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Michael A. Goldman
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Brinda Govindan
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Peter Ingmire
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Jonathan D. Knight
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Sally G. Pasion
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Pleuni S. Pennings
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | | | | | - Loretta Kelley
- Kelley, Peterson, and Associates, San Francisco, CA 94127
| | | | - Blake Riggs
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Laura W. Burrus
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Kimberly D. Tanner
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| |
Collapse
|
6
|
Dahlberg C(LL, King-Smith C, Riggs B. Building a laboratory at a Primarily Undergraduate Institution (PUI). BMC Proc 2021; 15:2. [PMID: 34158023 PMCID: PMC8218372 DOI: 10.1186/s12919-021-00208-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Scientists who are interested in building research programs at primarily-undergraduate institutions (PUIs) have unique considerations compared to colleagues at research-intensive (R1) institutions. Maintaining a research program at a PUI holds unique challenges that should be considered before prospective faculty go on the job market, as they negotiate a job offer, and after they begin a new position. In this article we describe some of the considerations that aspiring and newly hired faculty should keep in mind as they plan out how they will set up a laboratory as a new Principle Investigator (PI) at a PUI.Anyone hoping to start a research program at a PUI should understand both the timeframe of interviews, job offers, and negotiations and the challenges and rewards of working with undergraduate researchers. Once a job is offered, candidates should be aware of the range of negotiable terms that can be part of a start-up package. Space and equipment considerations are also important, and making the most of shared spaces, existing infrastructure, and deals can extend the purchasing power of start-up funds as a new PIs builds their lab. PUIs' focus on undergraduate education and mentorship leads to important opportunities for collaboration, funding, and bringing research projects directly into undergraduate teaching laboratories.A major focus of any new laboratory leader must be on building a productive, equitable, and supportive laboratory community. Equitable onboarding, mentorship plans, and formalized expectations, can all help build a productive and sustainable laboratory research program. However, important considerations about safety, inclusion, student schedules, and a PI's own professional commitments are also extremely important concerns when working with undergraduates in research. A successful research program at a PUI will bring students into meaningful scientific inquiry and requires insights and skills that are often not the focus of scientific training. This article aims to describe the scope of setting up a new laboratory as a way to alleviate some of the burden that new and prospective faculty often feel.
Collapse
Affiliation(s)
| | | | - Blake Riggs
- San Francisco State University, San Francisco, CA USA
| |
Collapse
|
7
|
Abstract
Diversifying the scientific workforce remains a national priority due to the continued lack of representation from underrepresented individuals in STEM fields. Quality mentoring has been identified as a stimulus to enhance not only research success, but also recruitment and retention of underrepresented groups pursuing STEM careers. Utilizing the Entering Mentoring training curriculum framework, this report provides a brief synopsis and key takeaways from the 2019 NIH-ASCB Accomplishing Career Transition (ACT) workshop, “Introduction to Effective Mentorship for Scientists” for 30 senior postdoctoral and early-career faculty researchers from historically underrepresented racial and ethnicity backgrounds. In addition, effective strategies and best practices to enhance STEM mentoring for early-career researchers are provided, which have practical applications for diverse mentoring relationships across disciplines, career stages, and mentee types.
Collapse
Affiliation(s)
| | | | - Blake Riggs
- Biology Department, San Francisco State University, San Francisco, CA, USA
| |
Collapse
|
8
|
King-Smith C, Lund Dahlberg CL, Riggs B. Obtaining a faculty position at a primarily undergraduate institution (PUI). BMC Proc 2021; 15:3. [PMID: 34158042 PMCID: PMC8217975 DOI: 10.1186/s12919-021-00207-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Scientists who hope to obtain a faculty position at a primarily undergraduate institution (PUI) need a distinct skill set and outlook on their future teaching and research career. To obtain a position at a PUI, candidates should 1) design a strategy for obtaining a faculty position that suits each individual’s career goals and aspirations, 2) prepare for the application process, on-campus interview, and contract negotiations, and 3) plan a strategy for the probationary period leading up to tenure and promotion. Given the different types of PUIs, candidates need to consider whether they seek a position that consists of all or mostly all teaching, or both teaching and research. Candidates should educate themselves on the expectations at PUI’s, including current thought, practice, and aspirations for science pedagogy, and gain teaching experience prior to seeking a suitable position. If the candidate’s goal is a position with both teaching and research, it is important to discuss with the current research mentor what projects the candidate can take with them to their new position. The candidate should also consider what types of projects will be successful with undergraduate student researchers in a PUI research environment. Importantly, candidates should clearly demonstrate a commitment to diversity and inclusion in their teaching, research, and outreach, and application materials should demonstrate this. On interviews, candidates should be knowledgeable about the mission, values, and resources of the institution and how the candidate will contribute to that mission. Once hired, new faculty should discuss a formal or informal mentoring plan during the probationary period that includes peer evaluations on a regular basis, and maintain communication with the department chair or designated mentor regarding teaching, research, and service activities.
Collapse
Affiliation(s)
| | | | - Blake Riggs
- San Francisco State University, San Francisco, CA, USA
| |
Collapse
|
9
|
Riggs B. Training matters! Narrative from a Black scientist. Mol Biol Cell 2021; 32:223-225. [PMID: 33507107 PMCID: PMC8098826 DOI: 10.1091/mbc.e20-07-0443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 11/09/2020] [Accepted: 12/03/2020] [Indexed: 11/11/2022] Open
Abstract
As STEM (Science, Technology, Engineering, and Math) professionals, we are tasked with increasing our understanding of the universe and generating discoveries that advance our society. An essential aspect is the training of the next generation of scientists, including concerted efforts to increase diversity within the scientific field. Despite these efforts, there remains disproportional underrepresentation of Black scientists in STEM. Further, efforts to recruit and hire Black faculty and researchers have been largely unsuccessful, in part due to a lack of minority candidates. Several factors contribute to this including access to opportunities, negative training experiences, lack of effective mentoring, and other more lucrative career options. This is a narrative of a Black male scientist to illustrate some of the issues in retaining Black students in STEM and to highlight the impact of toxic training environments that exists at many institutions. To increase Black participation in STEM careers, we must first acknowledge, then address, the problems that exist within our STEM training environments in hopes to inspire and retain Black students at every level of training.
Collapse
Affiliation(s)
- Blake Riggs
- Biology Department, San Francisco State University, San Francisco, CA 94132
| |
Collapse
|
10
|
Diaz U, Marshall W, Riggs B. Drosophila Embryo Preparation and Microinjection for Live Cell Microscopy Performed using an Automated High Content Analyzer. J Vis Exp 2021. [PMID: 33554960 DOI: 10.3791/61589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Modern approaches in quantitative live cell imaging have become an essential tool for exploring cell biology, by enabling the use of statistics and computational modeling to classify and compare biological processes. Although cell culture model systems are great for high content imaging, high throughput studies of cell morphology suggest that ex vivo cultures are limited in recapitulating the morphological complexity found in cells within living organisms. As such, there is a need for a scalable high throughput model system to image living cells within an intact organism. Described here is a protocol for using a high content image analyzer to simultaneously acquire multiple time-lapse videos of embryonic Drosophila melanogaster development during the syncytial blastoderm stage. The syncytial blastoderm has traditionally served as a great in vivo model for imaging biological events; however, obtaining a significant number of experimental replicates for quantitative and high-throughput approaches has been labor intensive and limited by the imaging of a single embryo per experimental repeat. Presented here is a method to adapt imaging and microinjection approaches to suit a high content imaging system, or any inverted microscope capable of automated multipoint acquisition. This approach enables the simultaneous acquisition of 6-12 embryos, depending on desired acquisition factors, within a single imaging session.
Collapse
Affiliation(s)
- Ulises Diaz
- Department of Biology, San Francisco State University; Department of Biochemistry & Biophysics, UCSF Mission Bay
| | | | - Blake Riggs
- Department of Biology, San Francisco State University;
| |
Collapse
|
11
|
Govindan B, Pickett S, Riggs B. Fear of the CURE: A Beginner's Guide to Overcoming Barriers in Creating a Course-Based Undergraduate Research Experience. J Microbiol Biol Educ 2020; 21:jmbe-21-48. [PMID: 32528607 PMCID: PMC7243983 DOI: 10.1128/jmbe.v21i2.2109] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 04/10/2020] [Indexed: 05/21/2023]
Abstract
Over the past decade, growing evidence has shown that there are many benefits to undergraduate students engaging in scientific research, including increased persistence in pursuing STEM careers and successful outcomes in graduate study. With these benefits in mind, there has been a significant push toward providing research opportunities for students in STEM majors. To address this need, an increasing number of undergraduate courses have been developed to provide students with research experiences in a class setting, also known as course-based undergraduate research experiences, or CUREs. Despite the growing success of these courses, a number of barriers remain that deter faculty from developing and implementing CUREs. Here, we will review the perceived challenges of developing a CURE and provide practical strategies to overcome these challenges.
Collapse
Affiliation(s)
- Brinda Govindan
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Sarah Pickett
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Center for Teaching and Learning, University of California, Berkeley, Berkeley, CA 94720
| | - Blake Riggs
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Corresponding author. Mailing address: Department of Biology, 1600 Holloway Ave., San Francisco State University, San Francisco, CA 94132. Phone: 415-338-1499. E-mail:
| |
Collapse
|
12
|
Diaz U, Bergman ZJ, Johnson BM, Edington AR, de Cruz MA, Marshall WF, Riggs B. Microtubules are necessary for proper Reticulon localization during mitosis. PLoS One 2019; 14:e0226327. [PMID: 31877164 PMCID: PMC6932760 DOI: 10.1371/journal.pone.0226327] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Accepted: 11/25/2019] [Indexed: 01/04/2023] Open
Abstract
During mitosis, the structure of the Endoplasmic Reticulum (ER) displays a dramatic reorganization and remodeling, however, the mechanism driving these changes is poorly understood. Hairpin-containing ER transmembrane proteins that stabilize ER tubules have been identified as possible factors to promote these drastic changes in ER morphology. Recently, the Reticulon and REEP family of ER shaping proteins have been shown to heavily influence ER morphology by driving the formation of ER tubules, which are known for their close proximity with microtubules. Here, we examine the role of microtubules and other cytoskeletal factors in the dynamics of a Drosophila Reticulon, Reticulon-like 1 (Rtnl1), localization to spindle poles during mitosis in the early embryo. At prometaphase, Rtnl1 is enriched to spindle poles just prior to the ER retention motif KDEL, suggesting a possible recruitment role for Rtnl1 in the bulk localization of ER to spindle poles. Using image analysis-based methods and precise temporal injections of cytoskeletal inhibitors in the early syncytial Drosophila embryo, we show that microtubules are necessary for proper Rtnl1 localization to spindles during mitosis. Lastly, we show that astral microtubules, not microfilaments, are necessary for proper Rtnl1 localization to spindle poles, and is largely independent of the minus-end directed motor protein dynein. This work highlights the role of the microtubule cytoskeleton in Rtnl1 localization to spindles during mitosis and sheds light on a pathway towards inheritance of this major organelle.
Collapse
Affiliation(s)
- Ulises Diaz
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
- Department of Biochemistry & Biophysics, UCSF Mission Bay, San Francisco, California, United States of America
| | - Zane J. Bergman
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Brittany M. Johnson
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Alia R. Edington
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Matthew A. de Cruz
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
| | - Wallace F. Marshall
- Department of Biochemistry & Biophysics, UCSF Mission Bay, San Francisco, California, United States of America
| | - Blake Riggs
- Department of Biology, San Francisco State University, San Francisco, California, United States of America
- * E-mail:
| |
Collapse
|
13
|
Harrison CD, Nguyen TA, Seidel SB, Escobedo AM, Hartman C, Lam K, Liang KS, Martens M, Acker GN, Akana SF, Balukjian B, Benton HP, Blair JR, Boaz SM, Boyer KE, Bram JB, Burrus LW, Byrd DT, Caporale N, Carpenter EJ, Chan YHM, Chen L, Chovnick A, Chu DS, Clarkson BK, Cooper SE, Creech CJ, de la Torre JR, Denetclaw WF, Duncan K, Edwards AS, Erickson K, Fuse M, Gorga JJ, Govindan B, Green LJ, Hankamp PZ, Harris HE, He ZH, Ingalls SB, Ingmire PD, Jacobs JR, Kamakea M, Kimpo RR, Knight JD, Krause SK, Krueger LE, Light TL, Lund L, Márquez-Magaña LM, McCarthy BK, McPheron L, Miller-Sims VC, Moffatt CA, Muick PC, Nagami PH, Nusse G, Okimura KM, Pasion SG, Patterson R, Pennings PS, Riggs B, Romeo JM, Roy SW, Russo-Tait T, Schultheis LM, Sengupta L, Spicer GS, Swei A, Wade JM, Willsie JK, Kelley LA, Owens MT, Trujillo G, Domingo C, Schinske JN, Tanner KD. Investigating Instructor Talk in Novel Contexts: Widespread Use, Unexpected Categories, and an Emergent Sampling Strategy. CBE Life Sci Educ 2019; 18:ar47. [PMID: 31469624 PMCID: PMC6755320 DOI: 10.1187/cbe.18-10-0215] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Instructor Talk-noncontent language used by instructors in classrooms-is a recently defined and promising variable for better understanding classroom dynamics. Having previously characterized the Instructor Talk framework within the context of a single course, we present here our results surrounding the applicability of the Instructor Talk framework to noncontent language used by instructors in novel course contexts. We analyzed Instructor Talk in eight additional biology courses in their entirety and in 61 biology courses using an emergent sampling strategy. We observed widespread use of Instructor Talk with variation in the amount and category type used. The vast majority of Instructor Talk could be characterized using the originally published Instructor Talk framework, suggesting the robustness of this framework. Additionally, a new form of Instructor Talk-Negatively Phrased Instructor Talk, language that may discourage students or distract from the learning process-was detected in these novel course contexts. Finally, the emergent sampling strategy described here may allow investigation of Instructor Talk in even larger numbers of courses across institutions and disciplines. Given its widespread use, potential influence on students in learning environments, and ability to be sampled, Instructor Talk may be a key variable to consider in future research on teaching and learning in higher education.
Collapse
Affiliation(s)
- Colin D. Harrison
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332
| | - Tiffy A. Nguyen
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Shannon B. Seidel
- Department of Biology, Pacific Lutheran University, Tacoma, WA 98447
| | - Alycia M. Escobedo
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Department of Education, University of California, Los Angeles, Los Angeles, CA 90095
| | - Courtney Hartman
- Department of Biology, Pacific Lutheran University, Tacoma, WA 98447
| | - Katie Lam
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Kristen S. Liang
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- School of Pharmacy, University of Southern California, Los Angeles, CA 90007
| | - Miranda Martens
- Department of Biology, Pacific Lutheran University, Tacoma, WA 98447
| | - Gigi N. Acker
- Department of Biology, De Anza College, Cupertino, CA 95014
| | - Susan F. Akana
- Department of Biology, City College of San Francisco, San Francisco, CA 94112
| | - Brad Balukjian
- Department of Biology, Merritt College, Oakland, CA 94619
| | - Hilary P. Benton
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Department of Biology, Foothill College, Los Altos Hills, CA 94022
| | - J. R. Blair
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Segal M. Boaz
- Department of Biology, Las Positas College, Livermore, CA 94551
| | - Katharyn E. Boyer
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Jason B. Bram
- Department of Biology, De Anza College, Cupertino, CA 95014
| | - Laura W. Burrus
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Dana T. Byrd
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Natalia Caporale
- Department of Neurobiology, Physiology, and Behavior, University of California, Davis, Davis, CA 95616
| | - Edward J. Carpenter
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Yee-Hung M. Chan
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Lily Chen
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Amy Chovnick
- Department of Biology, Las Positas College, Livermore, CA 94551
| | - Diana S. Chu
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Bryan K. Clarkson
- Division of Biological Sciences, Diablo Valley College, Pleasant Hill, CA 94523
| | - Sara E. Cooper
- Biological and Health Sciences, Foothill College, Los Altos Hills, CA 94022
| | | | - José R. de la Torre
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | | | - Kathleen Duncan
- Biological and Health Sciences, Foothill College, Los Altos Hills, CA 94022
| | | | - Karen Erickson
- Department of Biology, Foothill College, Los Altos Hills, CA 94022
| | - Megumi Fuse
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Joseph J. Gorga
- Division of Biological Sciences, Diablo Valley College, Pleasant Hill, CA 94523
| | - Brinda Govindan
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - L. Jeanette Green
- Science and Technology Division, Cañada College, Redwood City, CA 94061
| | - Paul Z. Hankamp
- Department of Biology, College of San Mateo, San Mateo, CA 94402
| | - Holly E. Harris
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Zheng-Hui He
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Stephen B. Ingalls
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Peter D. Ingmire
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - J. Rebecca Jacobs
- Biological and Health Sciences, Foothill College, Los Altos Hills, CA 94022
| | - Mark Kamakea
- Department of Biology, Chabot College, Hayward, CA 94545
| | - Rhea R. Kimpo
- Department of Biology, Samuel Merritt University, Oakland, CA 94609
| | - Jonathan D. Knight
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Sara K. Krause
- Department of Biology, Palomar College, San Marcos, CA 92069
| | - Lori E. Krueger
- Department of Biological Sciences, Sacramento State University, Sacramento, CA 95819
| | - Terrye L. Light
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Lance Lund
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | | | | | - Linda McPheron
- Department of Biology, Berkeley City College, Berkeley, CA 94704
| | | | | | - Pamela C. Muick
- Department of Biology, Contra Costa College, San Pablo, CA 94806
- Department of Biology, Solano College, Fairfield, CA 94534
| | - Paul H. Nagami
- Department of Biology, Holy Names University, Oakland, CA 94619
| | - Gloria Nusse
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - K. M. Okimura
- Department of Earth and Climate Sciences, San Francisco State University, San Francisco, CA 94132
| | - Sally G. Pasion
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Robert Patterson
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Pleuni S. Pennings
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Blake Riggs
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Joseph M. Romeo
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Scott W. Roy
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | | | | | - Lakshmikanta Sengupta
- Department of Biology, De Anza College, Cupertino, CA 95014
- Department of Biology, College of San Mateo, San Mateo, CA 94402
| | - Greg S. Spicer
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Andrea Swei
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Jennifer M. Wade
- Department of Biology, Massachusetts College of Pharmacy and Health Sciences, Boston, MA 02115
| | - Julia K. Willsie
- Division of Biological Sciences, Diablo Valley College, Pleasant Hill, CA 94523
| | | | - Melinda T. Owens
- Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093
| | - Gloriana Trujillo
- Office of the Vice Provost for Teaching and Learning, Stanford University, Stanford, CA 94305
| | - Carmen Domingo
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | | | - Kimberly D. Tanner
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- *Address correspondence to: Kimberly D. Tanner ()
| |
Collapse
|
14
|
del Castillo U, Gnazzo MM, Turpin CGS, Nguyen KCQ, Semaya E, Lam Y, de Cruz MA, Bembenek JN, Hall DH, Riggs B, Gelfand VI, Skop AR. Conserved role for Ataxin-2 in mediating endoplasmic reticulum dynamics. Traffic 2019; 20:436-447. [PMID: 30989774 PMCID: PMC6553494 DOI: 10.1111/tra.12647] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 04/04/2019] [Accepted: 04/05/2019] [Indexed: 12/17/2022]
Abstract
Ataxin-2, a conserved RNA-binding protein, is implicated in the late-onset neurodegenerative disease Spinocerebellar ataxia type-2 (SCA2). SCA2 is characterized by shrunken dendritic arbors and torpedo-like axons within the Purkinje neurons of the cerebellum. Torpedo-like axons have been described to contain displaced endoplasmic reticulum (ER) in the periphery of the cell; however, the role of Ataxin-2 in mediating ER function in SCA2 is unclear. We utilized the Caenorhabditis elegans and Drosophila homologs of Ataxin-2 (ATX-2 and DAtx2, respectively) to determine the role of Ataxin-2 in ER function and dynamics in embryos and neurons. Loss of ATX-2 and DAtx2 resulted in collapse of the ER in dividing embryonic cells and germline, and ultrastructure analysis revealed unique spherical stacks of ER in mature oocytes and fragmented and truncated ER tubules in the embryo. ATX-2 and DAtx2 reside in puncta adjacent to the ER in both C. elegans and Drosophila embryos. Lastly, depletion of DAtx2 in cultured Drosophila neurons recapitulated the shrunken dendritic arbor phenotype of SCA2. ER morphology and dynamics were severely disrupted in these neurons. Taken together, we provide evidence that Ataxin-2 plays an evolutionary conserved role in ER dynamics and morphology in C. elegans and Drosophila embryos during development and in fly neurons, suggesting a possible SCA2 disease mechanism.
Collapse
Affiliation(s)
- Urko del Castillo
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, 303 E Chicago Ave, Chicago, IL 60611
| | - Megan M. Gnazzo
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706
| | - Christopher G. Sorensen Turpin
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee-Knoxville, Knoxville, Tennessee 37996
| | - Ken C. Q. Nguyen
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx New York, NY 10461
| | - Emily Semaya
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx New York, NY 10461
| | - Yuwan Lam
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Matthew A. de Cruz
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Joshua N. Bembenek
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee-Knoxville, Knoxville, Tennessee 37996
| | - David H. Hall
- Center for C. elegans Anatomy, Albert Einstein College of Medicine, Bronx New York, NY 10461
| | - Blake Riggs
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Vladimir I. Gelfand
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, 303 E Chicago Ave, Chicago, IL 60611
| | - Ahna R. Skop
- Laboratory of Genetics, University of Wisconsin-Madison, Madison, WI 53706
| |
Collapse
|
15
|
Owens MT, Trujillo G, Seidel SB, Harrison CD, Farrar KM, Benton HP, Blair JR, Boyer KE, Breckler JL, Burrus LW, Byrd DT, Caporale N, Carpenter EJ, Chan YHM, Chen JC, Chen L, Chen LH, Chu DS, Cochlan WP, Crook RJ, Crow KD, de la Torre JR, Denetclaw WF, Dowdy LM, Franklin D, Fuse M, Goldman MA, Govindan B, Green M, Harris HE, He ZH, Ingalls SB, Ingmire P, Johnson ARB, Knight JD, LeBuhn G, Light TL, Low C, Lund L, Márquez-Magaña LM, Miller-Sims VC, Moffatt CA, Murdock H, Nusse GL, Parker VT, Pasion SG, Patterson R, Pennings PS, Ramirez JC, Ramirez RM, Riggs B, Rohlfs RV, Romeo JM, Rothman BS, Roy SW, Russo-Tait T, Sehgal RNM, Simonin KA, Spicer GS, Stillman JH, Swei A, Timpe LC, Vredenburg VT, Weinstein SL, Zink AG, Kelley LA, Domingo CR, Tanner KD. Collectively Improving Our Teaching: Attempting Biology Department-wide Professional Development in Scientific Teaching. CBE Life Sci Educ 2018; 17:ar2. [PMID: 29326102 PMCID: PMC6007775 DOI: 10.1187/cbe.17-06-0106] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 10/23/2017] [Accepted: 11/06/2017] [Indexed: 05/10/2023]
Abstract
Many efforts to improve science teaching in higher education focus on a few faculty members at an institution at a time, with limited published evidence on attempts to engage faculty across entire departments. We created a long-term, department-wide collaborative professional development program, Biology Faculty Explorations in Scientific Teaching (Biology FEST). Across 3 years of Biology FEST, 89% of the department's faculty completed a weeklong scientific teaching institute, and 83% of eligible instructors participated in additional semester-long follow-up programs. A semester after institute completion, the majority of Biology FEST alumni reported adding active learning to their courses. These instructor self-reports were corroborated by audio analysis of classroom noise and surveys of students in biology courses on the frequency of active-learning techniques used in classes taught by Biology FEST alumni and nonalumni. Three years after Biology FEST launched, faculty participants overwhelmingly reported that their teaching was positively affected. Unexpectedly, most respondents also believed that they had improved relationships with departmental colleagues and felt a greater sense of belonging to the department. Overall, our results indicate that biology department-wide collaborative efforts to develop scientific teaching skills can indeed attract large numbers of faculty, spark widespread change in teaching practices, and improve departmental relations.
Collapse
Affiliation(s)
- Melinda T Owens
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Gloriana Trujillo
- Office of the Vice Provost for Teaching and Learning, Stanford University, Stanford, CA 94305
| | - Shannon B Seidel
- Department of Biology, Pacific Lutheran University, Tacoma, WA 98447
| | - Colin D Harrison
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA 30332
| | - Katherine M Farrar
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Hilary P Benton
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - J R Blair
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Katharyn E Boyer
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Romberg Tiburon Center for Environmental Studies, San Francisco State University, Tiburon, CA 94920
| | - Jennifer L Breckler
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Laura W Burrus
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Dana T Byrd
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Natalia Caporale
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA 95616
| | - Edward J Carpenter
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Romberg Tiburon Center for Environmental Studies, San Francisco State University, Tiburon, CA 94920
| | - Yee-Hung M Chan
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Joseph C Chen
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Lily Chen
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Linda H Chen
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Diana S Chu
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - William P Cochlan
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Romberg Tiburon Center for Environmental Studies, San Francisco State University, Tiburon, CA 94920
| | - Robyn J Crook
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Karen D Crow
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - José R de la Torre
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Wilfred F Denetclaw
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Lynne M Dowdy
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Darleen Franklin
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Megumi Fuse
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Michael A Goldman
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Brinda Govindan
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Michael Green
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Holly E Harris
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Zheng-Hui He
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Stephen B Ingalls
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Peter Ingmire
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Division of Undergraduate Education and Academic Planning, San Francisco State University, San Francisco, CA 94132
| | - Amber R B Johnson
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Jonathan D Knight
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Gretchen LeBuhn
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Terrye L Light
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Candace Low
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Lance Lund
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | | | | | | | - Heather Murdock
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Gloria L Nusse
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - V Thomas Parker
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Sally G Pasion
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Robert Patterson
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Pleuni S Pennings
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Julio C Ramirez
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Robert M Ramirez
- College of Science and Engineering, San Francisco State University, San Francisco, CA 94132
| | - Blake Riggs
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Rori V Rohlfs
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Joseph M Romeo
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Barry S Rothman
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Scott W Roy
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Tatiane Russo-Tait
- Department of Curriculum and Instruction, STEM Education, University of Texas at Austin, Austin, TX 78712
| | - Ravinder N M Sehgal
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Kevin A Simonin
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Greg S Spicer
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Jonathon H Stillman
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Romberg Tiburon Center for Environmental Studies, San Francisco State University, Tiburon, CA 94920
| | - Andrea Swei
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Leslie C Timpe
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- Department of Mathematics, San Francisco State University, San Francisco, CA 94132
| | - Vance T Vredenburg
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Steven L Weinstein
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Andrew G Zink
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Loretta A Kelley
- Kelley, Petterson, and Associates, Inc., San Francisco, CA 94127
| | - Carmen R Domingo
- Department of Biology, San Francisco State University, San Francisco, CA 94132
- College of Science and Engineering, San Francisco State University, San Francisco, CA 94132
| | - Kimberly D Tanner
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| |
Collapse
|
16
|
Eritano AS, Altamirano A, Beyeler S, Gaytan N, Velasquez M, Riggs B. The endoplasmic reticulum is partitioned asymmetrically during mitosis before cell fate selection in proneuronal cells in the early Drosophila embryo. Mol Biol Cell 2017; 28:1530-1538. [PMID: 28381427 PMCID: PMC5449151 DOI: 10.1091/mbc.e16-09-0690] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2016] [Revised: 03/28/2017] [Accepted: 03/28/2017] [Indexed: 11/19/2022] Open
Abstract
In the early Drosophila embryo, epithelial cells begin to adopt a cell fate. At gastrulation, there is an asymmetric partitioning of the endoplasmic reticulum in a symmetrically dividing cell population before cell fate selection. These results highlight the changes in organelle distribution before asymmetric divisions. Asymmetric cell division is the primary mechanism to generate cellular diversity, and it relies on the correct partitioning of cell fate determinants. However, the mechanism by which these determinants are delivered and positioned is poorly understood, and the upstream signal to initiate asymmetric cell division is unknown. Here we report that the endoplasmic reticulum (ER) is asymmetrically partitioned during mitosis in epithelial cells just before delamination and selection of a proneural cell fate in the early Drosophila embryo. At the start of gastrulation, the ER divides asymmetrically into a population of asynchronously dividing cells at the anterior end of the embryo. We found that this asymmetric division of the ER depends on the highly conserved ER membrane protein Jagunal (Jagn). RNA inhibition of jagn just before the start of gastrulation disrupts this asymmetric division of the ER. In addition, jagn-deficient embryos display defects in apical-basal spindle orientation in delaminated embryonic neuroblasts. Our results describe a model in which an organelle is partitioned asymmetrically in an otherwise symmetrically dividing cell population just upstream of cell fate determination and updates previous models of spindle-based selection of cell fate during mitosis.
Collapse
Affiliation(s)
- Anthony S Eritano
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Arturo Altamirano
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Sarah Beyeler
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Norma Gaytan
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Mark Velasquez
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| | - Blake Riggs
- Department of Biology, San Francisco State University, San Francisco, CA 94132
| |
Collapse
|
17
|
Smyth JT, Schoborg TA, Bergman ZJ, Riggs B, Rusan NM. Proper symmetric and asymmetric endoplasmic reticulum partitioning requires astral microtubules. Open Biol 2016; 5:rsob.150067. [PMID: 26289801 PMCID: PMC4554919 DOI: 10.1098/rsob.150067] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Mechanisms that regulate partitioning of the endoplasmic reticulum (ER) during cell division are largely unknown. Previous studies have mostly addressed ER partitioning in cultured cells, which may not recapitulate physiological processes that are critical in developing, intact tissues. We have addressed this by analysing ER partitioning in asymmetrically dividing stem cells, in which precise segregation of cellular components is essential for proper development and tissue architecture. We show that in Drosophila neural stem cells, called neuroblasts, the ER asymmetrically partitioned to centrosomes early in mitosis. This correlated closely with the asymmetric nucleation of astral microtubules (MTs) by centrosomes, suggesting that astral MT association may be required for ER partitioning by centrosomes. Consistent with this, the ER also associated with astral MTs in meiotic Drosophila spermatocytes and during syncytial embryonic divisions. Disruption of centrosomes in each of these cell types led to improper ER partitioning, demonstrating the critical role for centrosomes and associated astral MTs in this process. Importantly, we show that the ER also associated with astral MTs in cultured human cells, suggesting that this centrosome/astral MT-based partitioning mechanism is conserved across animal species.
Collapse
Affiliation(s)
- Jeremy T Smyth
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences-F. Edward Hébert School of Medicine, Bethesda, MD 20814, USA
| | - Todd A Schoborg
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Zane J Bergman
- Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132, USA
| | - Blake Riggs
- Department of Biology, San Francisco State University, 1600 Holloway Avenue, San Francisco, CA 94132, USA
| | - Nasser M Rusan
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
18
|
Trujillo G, Aguinaldo PG, Anderson C, Bustamante J, Gelsinger DR, Pastor MJ, Wright J, Márquez-Magaña L, Riggs B. Near-peer STEM Mentoring Offers Unexpected Benefits for Mentors from Traditionally Underrepresented Backgrounds. Perspect Undergrad Res Mentor 2015; 4:http://blogs.elon.edu/purm/files/2015/11/Riggs.GT-et-al-PURM-4.1.pdf. [PMID: 27668127 PMCID: PMC5034940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
|
19
|
Bergman ZJ, Mclaurin JD, Eritano AS, Johnson BM, Sims AQ, Riggs B. Spatial reorganization of the endoplasmic reticulum during mitosis relies on mitotic kinase cyclin A in the early Drosophila embryo. PLoS One 2015; 10:e0117859. [PMID: 25689737 PMCID: PMC4331435 DOI: 10.1371/journal.pone.0117859] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2014] [Accepted: 12/24/2014] [Indexed: 11/19/2022] Open
Abstract
Mitotic cyclin-dependent kinase with their cyclin partners (cyclin:Cdks) are the master regulators of cell cycle progression responsible for regulating a host of activities during mitosis. Nuclear mitotic events, including chromosome condensation and segregation have been directly linked to Cdk activity. However, the regulation and timing of cytoplasmic mitotic events by cyclin:Cdks is poorly understood. In order to examine these mitotic cytoplasmic events, we looked at the dramatic changes in the endoplasmic reticulum (ER) during mitosis in the early Drosophila embryo. The dynamic changes of the ER can be arrested in an interphase state by inhibition of either DNA or protein synthesis. Here we show that this block can be alleviated by micro-injection of Cyclin A (CycA) in which defined mitotic ER clusters gathered at the spindle poles. Conversely, micro-injection of Cyclin B (CycB) did not affect spatial reorganization of the ER, suggesting CycA possesses the ability to initiate mitotic ER events in the cytoplasm. Additionally, RNAi-mediated simultaneous inhibition of all 3 mitotic cyclins (A, B and B3) blocked spatial reorganization of the ER. Our results suggest that mitotic ER reorganization events rely on CycA and that control and timing of nuclear and cytoplasmic events during mitosis may be defined by release of CycA from the nucleus as a consequence of breakdown of the nuclear envelope.
Collapse
Affiliation(s)
- Zane J. Bergman
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, United States of America
| | - Justin D. Mclaurin
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, United States of America
| | - Anthony S. Eritano
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, United States of America
| | - Brittany M. Johnson
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, United States of America
| | - Amanda Q. Sims
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, United States of America
| | - Blake Riggs
- Department of Biology, San Francisco State University, 1600 Holloway Ave., San Francisco, California, 94132, United States of America
- * E-mail:
| |
Collapse
|
20
|
Riggs B, Bergman ZJ, Heald R. Altering membrane topology with Sar1 does not impair spindle assembly in Xenopus egg extracts. Cytoskeleton (Hoboken) 2012; 69:591-9. [PMID: 22605651 DOI: 10.1002/cm.21036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 04/13/2012] [Accepted: 04/24/2012] [Indexed: 11/12/2022]
Abstract
Intracellular membrane networks including the endoplasmic reticulum (ER) and the Golgi apparatus experience dramatic reorganization upon entry into mitosis. However, the mechanisms driving these rearrangements and their importance for cell division are poorly understood. The GTPase Sar1 is a component of the secretory pathway and a key activator of anterograde transport of cargo from the ER to the Golgi. Here we show that Sar1 mutant proteins added to metaphase-arrested Xenopus laevis egg extracts cause dramatic effects on membrane organization. Live analysis of membrane structures in egg extract cytoplasm revealed a distinct network of sheets and tubules reflective of the organization of the ER in other systems. Addition of a constitutively active Sar1 GTPase mutant (H79G) increased membrane tubulation, while a dominant negative version Sar1 (T39N) impaired tubule organization. Although microtubule pelleting assays revealed that Sar1 associates with microtubules in the egg extract, and addition of Sar1 (H79G) mutant slightly destabilized spindle poles, bipolar spindle assembly was largely unaffected. Thus, spindles are stable to dramatic changes in mitotic membrane organization at metaphase, suggesting that mitotic membrane is not an upstream regulator of the mitotic spindle apparatus in Xenopus egg extracts.
Collapse
Affiliation(s)
- Blake Riggs
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA.
| | | | | |
Collapse
|
21
|
Affiliation(s)
- Rose Loughlin
- Molecular and Cell Biology Department, University of California, Berkeley, CA 94720, USA
| | | | | |
Collapse
|
22
|
Cao J, Albertson R, Riggs B, Field CM, Sullivan W. Nuf, a Rab11 effector, maintains cytokinetic furrow integrity by promoting local actin polymerization. ACTA ACUST UNITED AC 2008; 182:301-13. [PMID: 18644888 PMCID: PMC2483530 DOI: 10.1083/jcb.200712036] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Plasma membrane ingression during cytokinesis involves both actin remodeling and vesicle-mediated membrane addition. Vesicle-based membrane delivery from the recycling endosome (RE) has an essential but ill-defined involvement in cytokinesis. In the Drosophila melanogaster early embryo, Nuf (Nuclear fallout), a Rab11 effector which is essential for RE function, is required for F-actin and membrane integrity during furrow ingression. We find that in nuf mutant embryos, an initial loss of F-actin at the furrow is followed by loss of the associated furrow membrane. Wild-type embryos treated with Latrunculin A or Rho inhibitor display similar defects. Drug- or Rho-GTP–induced increase of actin polymerization or genetically mediated decrease of actin depolymerization suppresses the nuf mutant F-actin and membrane defects. We also find that RhoGEF2 does not properly localize at the furrow in nuf mutant embryos and that RhoGEF2–Rho1 pathway components show strong specific genetic interactions with Nuf. We propose a model in which RE-derived vesicles promote furrow integrity by regulating the rate of actin polymerization through the RhoGEF2–Rho1 pathway.
Collapse
Affiliation(s)
- Jian Cao
- Sinsheimer Laboratories, Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | | | | | | | | |
Collapse
|
23
|
Andersen CB, Wan Y, Chang JW, Riggs B, Lee C, Liu Y, Sessa F, Villa F, Kwiatkowski N, Suzuki M, Nallan L, Heald R, Musacchio A, Gray NS. Discovery of selective aminothiazole aurora kinase inhibitors. ACS Chem Biol 2008; 3:180-92. [PMID: 18307303 DOI: 10.1021/cb700200w] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Aurora family kinases regulate important events during mitosis including centrosome maturation and separation, mitotic spindle assembly, and chromosome segregation. Misregulation of Aurora kinases due to genetic amplification and protein overexpression results in aneuploidy and may contribute to tumorigenesis. Here we report the discovery of new small molecule aminothiazole inhibitors of Aurora kinases with exceptional kinase selectivity and report a 1.7 A cocrystal structure with the Aurora B:INCENP complex from Xenopus laevis. The compounds recapitulate the hallmarks of Aurora kinase inhibition, including decreased histone H3 serine 10 phosphorylation, failure to complete cytokinesis, and endoreduplication.
Collapse
Affiliation(s)
- Carsten B. Andersen
- Department of Biological Chemistry,
Genomics Institute of the Novartis Research Foundation, 10675 John
Jay Hopkins Drive, San Diego, California 92121
| | - Yongqin Wan
- Department of Biological Chemistry,
Genomics Institute of the Novartis Research Foundation, 10675 John
Jay Hopkins Drive, San Diego, California 92121
| | - Jae W. Chang
- Department of Cancer Biology, Dana Farber Cancer Institute, Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 250 Longwood Avenue, Boston, Massachusetts 02115
| | - Blake Riggs
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720
| | - Christian Lee
- Department of Biological Chemistry,
Genomics Institute of the Novartis Research Foundation, 10675 John
Jay Hopkins Drive, San Diego, California 92121
| | - Yi Liu
- Department of Biological Chemistry,
Genomics Institute of the Novartis Research Foundation, 10675 John
Jay Hopkins Drive, San Diego, California 92121
| | - Fabio Sessa
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello, 16-20139 Milan, Italy
| | - Fabrizio Villa
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello, 16-20139 Milan, Italy
| | - Nicholas Kwiatkowski
- Department of Cancer Biology, Dana Farber Cancer Institute, Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 250 Longwood Avenue, Boston, Massachusetts 02115
| | | | - Laxman Nallan
- Department of Biological Chemistry,
Genomics Institute of the Novartis Research Foundation, 10675 John
Jay Hopkins Drive, San Diego, California 92121
| | - Rebecca Heald
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720
| | - Andrea Musacchio
- Department of Experimental Oncology, European Institute of Oncology, Via Adamello, 16-20139 Milan, Italy
| | - Nathanael S. Gray
- Department of Cancer Biology, Dana Farber Cancer Institute, Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 250 Longwood Avenue, Boston, Massachusetts 02115
| |
Collapse
|
24
|
Riggs B, Fasulo B, Royou A, Mische S, Cao J, Hays TS, Sullivan W. The concentration of Nuf, a Rab11 effector, at the microtubule-organizing center is cell cycle regulated, dynein-dependent, and coincides with furrow formation. Mol Biol Cell 2007; 18:3313-22. [PMID: 17581858 PMCID: PMC1951762 DOI: 10.1091/mbc.e07-02-0146] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 05/30/2007] [Accepted: 06/13/2007] [Indexed: 12/29/2022] Open
Abstract
Animal cytokinesis relies on membrane addition as well as acto-myosin-based constriction. Recycling endosome (RE)-derived vesicles are a key source of this membrane. Rab11, a small GTPase associated with the RE and involved in vesicle targeting, is required for elongation of the cytokinetic furrow. In the early Drosophila embryo, Nuclear-fallout (Nuf), a Rab11 effector, promotes vesicle-mediated membrane delivery and actin organization at the invaginating furrow. Although Rab11 maintains a relatively constant localization at the microtubule-organizing center (MTOC), Nuf is present at the MTOC only during the phases of the cell cycle in which furrow invagination occurs. We demonstrate that Nuf protein levels remain relatively constant throughout the cell cycle, suggesting that Nuf is undergoing cycles of concentration and dispersion from the MTOC. Microtubules, but not microfilaments, are required for proper MTOC localization of Nuf and Rab11. The MTOC localization of Nuf also relies on Dynein. Immunoprecipitation experiments demonstrate that Nuf and Dynein physically interact. In accord with these findings, and in contrast to previous reports, we demonstrate that microtubules are required for proper metaphase furrow formation. We propose that the cell cycle-regulated, Dynein-dependent recruitment of Nuf to the MTOC influences the timing of RE-based vesicle delivery to the invaginating furrows.
Collapse
Affiliation(s)
- Blake Riggs
- *Sinsheimer Laboratories, Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, CA 95064; and
| | - Barbara Fasulo
- *Sinsheimer Laboratories, Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, CA 95064; and
| | - Anne Royou
- *Sinsheimer Laboratories, Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, CA 95064; and
| | - Sarah Mische
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55108-1095
| | - Jian Cao
- *Sinsheimer Laboratories, Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, CA 95064; and
| | - Thomas S. Hays
- Department of Genetics, Cell Biology, and Development, University of Minnesota, Minneapolis, MN 55108-1095
| | - William Sullivan
- *Sinsheimer Laboratories, Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, CA 95064; and
| |
Collapse
|
25
|
Abstract
Dividing animal and plant cells maintain a constant chromosome content through temporally separated rounds of replication and segregation. Until recently, the mechanisms by which animal and plant cells maintain a constant surface area have been considered to be distinct. The prevailing view was that surface area was maintained in dividing animal cells through temporally separated rounds of membrane expansion and membrane invagination. The latter event, known as cytokinesis, produces two physically distinct daughter cells and has been thought to be primarily driven by actomyosin-based constriction. By contrast, membrane addition seems to be the primary mechanism that drives cytokinesis in plants and, thus, the two events are linked mechanistically and temporally. In this article (which is part of the Cytokinesis series), we discuss recent studies of a variety of organisms that have made a convincing case for membrane trafficking at the cleavage furrow being a key component of both animal and plant cytokinesis.
Collapse
Affiliation(s)
- Roger Albertson
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Cruz, CA 95064, USA
| | | | | |
Collapse
|
26
|
Riggs B, Rothwell W, Mische S, Hickson GRX, Matheson J, Hays TS, Gould GW, Sullivan W. Actin cytoskeleton remodeling during early Drosophila furrow formation requires recycling endosomal components Nuclear-fallout and Rab11. ACTA ACUST UNITED AC 2003; 163:143-54. [PMID: 14530382 PMCID: PMC2173427 DOI: 10.1083/jcb.200305115] [Citation(s) in RCA: 157] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Cytokinesis requires a dramatic remodeling of the cortical cytoskeleton as well as membrane addition. The Drosophila pericentrosomal protein, Nuclear-fallout (Nuf), provides a link between these two processes. In nuf-derived embryos, actin remodeling and membrane recruitment during the initial stages of metaphase and cellular furrow formation are disrupted. Nuf is a homologue of arfophilin-2, an ADP ribosylation factor effector that binds Rab11 and influences recycling endosome (RE) organization. Here, we show that Nuf is an important component of the RE, and that these phenotypes are a consequence of Nuf activities at the RE. Nuf exhibits extensive colocalization with Rab11, a key RE component. GST pull-downs and the presence of a conserved Rab11-binding domain in Nuf demonstrate that Nuf and Rab11 physically associate. In addition, Nuf and Rab11 are mutually required for their localization to the RE. Embryos with reduced levels of Rab11 produce membrane recruitment and actin remodeling defects strikingly similar to nuf-derived embryos. These analyses support a common role for Nuf and Rab11 at the RE in membrane trafficking and actin remodeling during the initial stages of furrow formation.
Collapse
Affiliation(s)
- Blake Riggs
- Deptartment of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Hickson GRX, Matheson J, Riggs B, Maier VH, Fielding AB, Prekeris R, Sullivan W, Barr FA, Gould GW. Arfophilins are dual Arf/Rab 11 binding proteins that regulate recycling endosome distribution and are related to Drosophila nuclear fallout. Mol Biol Cell 2003; 14:2908-20. [PMID: 12857874 PMCID: PMC165686 DOI: 10.1091/mbc.e03-03-0160] [Citation(s) in RCA: 118] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Arfophilin is an ADP ribosylation factor (Arf) binding protein of unknown function. It is identical to the Rab11 binding protein eferin/Rab11-FIP3, and we show it binds both Arf5 and Rab11. We describe a related protein, arfophilin-2, that interacts with Arf5 in a nucleotide-dependent manner, but not Arf1, 4, or 6 and also binds Rab11. Arfophilin-2 localized to a perinuclear compartment, the centrosomal area, and focal adhesions. The localization of arfophilin-2 to the perinuclear compartment was selectively blocked by overexpression of Arf5-T31N. In contrast, a green fluorescent protein-arfophilin-2 chimera or arfophilin-2 deletions were localized around the centrosome in a region that was also enriched for transferrin receptors and Rab11 but not early endosome markers, suggesting that the distribution of the endosomal recycling compartment was altered. The arfophilins belong to a conserved family that includes Drosophila melanogaster nuclear fallout, a centrosomal protein required for cellularization. Expression of green fluorescent protein-nuclear fallout in HeLa cells resulted in a similar phenotype, indicative of functional homology and thus implicating the arfophilins in mitosis/cytokinesis. We suggest that the novel dual GTPase-binding capacity of the arfophilins could serve as an interface of signals from Rab and Arf GTPases to regulate membrane traffic and integrate distinct signals in the late endosomal recycling compartment.
Collapse
Affiliation(s)
- Gilles R X Hickson
- The Henry Wellcome Laboratory of Cell Biology, Division of Biochemistry and Molecular Biology, Faculty of Biomedical and Life Sciences, University of Glasgow, Glasgow G12 8QQ, Scotland
| | | | | | | | | | | | | | | | | |
Collapse
|
28
|
Affiliation(s)
- U Tram
- University of California, Santa Cruz, Department of Biology, Sinshiemer Laboratories, Santa Cruz, California 95064, USA
| | | | | | | | | |
Collapse
|
29
|
Hulley S, Grady D, Bush T, Furberg C, Herrington D, Riggs B, Vittinghoff E. Randomized trial of estrogen plus progestin for secondary prevention of coronary heart disease in postmenopausal women. Heart and Estrogen/progestin Replacement Study (HERS) Research Group. JAMA 1998; 280:605-13. [PMID: 9718051 DOI: 10.1001/jama.280.7.605] [Citation(s) in RCA: 3849] [Impact Index Per Article: 148.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT Observational studies have found lower rates of coronary heart disease (CHD) in postmenopausal women who take estrogen than in women who do not, but this potential benefit has not been confirmed in clinical trials. OBJECTIVE To determine if estrogen plus progestin therapy alters the risk for CHD events in postmenopausal women with established coronary disease. DESIGN Randomized, blinded, placebo-controlled secondary prevention trial. SETTING Outpatient and community settings at 20 US clinical centers. PARTICIPANTS A total of 2763 women with coronary disease, younger than 80 years, and postmenopausal with an intact uterus. Mean age was 66.7 years. INTERVENTION Either 0.625 mg of conjugated equine estrogens plus 2.5 mg of medroxyprogesterone acetate in 1 tablet daily (n = 1380) or a placebo of identical appearance (n = 1383). Follow-up averaged 4.1 years; 82% of those assigned to hormone treatment were taking it at the end of 1 year, and 75% at the end of 3 years. MAIN OUTCOME MEASURES The primary outcome was the occurrence of nonfatal myocardial infarction (MI) or CHD death. Secondary cardiovascular outcomes included coronary revascularization, unstable angina, congestive heart failure, resuscitated cardiac arrest, stroke or transient ischemic attack, and peripheral arterial disease. All-cause mortality was also considered. RESULTS Overall, there were no significant differences between groups in the primary outcome or in any of the secondary cardiovascular outcomes: 172 women in the hormone group and 176 women in the placebo group had MI or CHD death (relative hazard [RH], 0.99; 95% confidence interval [CI], 0.80-1.22). The lack of an overall effect occurred despite a net 11% lower low-density lipoprotein cholesterol level and 10% higher high-density lipoprotein cholesterol level in the hormone group compared with the placebo group (each P<.001). Within the overall null effect, there was a statistically significant time trend, with more CHD events in the hormone group than in the placebo group in year 1 and fewer in years 4 and 5. More women in the hormone group than in the placebo group experienced venous thromboembolic events (34 vs 12; RH, 2.89; 95% CI, 1.50-5.58) and gallbladder disease (84 vs 62; RH, 1.38; 95% CI, 1.00-1.92). There were no significant differences in several other end points for which power was limited, including fracture, cancer, and total mortality (131 vs 123 deaths; RH, 1.08; 95% CI, 0.84-1.38). CONCLUSIONS During an average follow-up of 4.1 years, treatment with oral conjugated equine estrogen plus medroxyprogesterone acetate did not reduce the overall rate of CHD events in postmenopausal women with established coronary disease. The treatment did increase the rate of thromboembolic events and gallbladder disease. Based on the finding of no overall cardiovascular benefit and a pattern of early increase in risk of CHD events, we do not recommend starting this treatment for the purpose of secondary prevention of CHD. However, given the favorable pattern of CHD events after several years of therapy, it could be appropriate for women already receiving this treatment to continue.
Collapse
Affiliation(s)
- S Hulley
- University of California, San Francisco 94143, USA
| | | | | | | | | | | | | |
Collapse
|
30
|
Grady D, Applegate W, Bush T, Furberg C, Riggs B, Hulley SB. Heart and Estrogen/progestin Replacement Study (HERS): design, methods, and baseline characteristics. Control Clin Trials 1998; 19:314-35. [PMID: 9683309 DOI: 10.1016/s0197-2456(98)00010-5] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The Heart and Estrogen/progestin Replacement Study (HERS) is a randomized, double-blind, placebo-controlled trial designed to test the efficacy and safety of estrogen plus progestin therapy for prevention of recurrent coronary heart disease (CHD) events in women. The participants are postmenopausal women with a uterus and with CHD as evidenced by prior myocardial infarction, coronary artery bypass graft surgery, percutaneous transluminal coronary angioplasty, or other mechanical revascularization or at least 50% occlusion of a major coronary artery. Between February 1993 and September 1994, 20 HERS centers recruited and randomized 2763 women. Participants ranged in age from 44 to 79 years, with a mean age of 66.7 (SD 6.7) years. Most participants were white (89%), married (57%), and had completed high school or some college (80%). As expected, the prevalence of coronary risk factors was high: 62% were past or current smokers, 59% had hypertension, 90% had serum LDL-cholesterol of 100 mg/dL or higher, and 23% had diabetes. Each woman was randomly assigned to receive one tablet containing 0.625 mg conjugated estrogens plus 2.5 mg medroxyprogesterone acetate daily or an identical placebo. Participants will be evaluated every 4 months for an average of 4.2 years for the occurrence of CHD events (CHD death and nonfatal myocardial infarction). We will also assess other major CHD endpoints, including revascularization and hospitalization for unstable angina. The primary analysis will compare the rate of CHD events in women assigned to active treatment with the rate in those assigned to placebo. The trial was designed to have power greater than 90% to detect a 35% reduction in the incidence of CHD events, assuming a 50% lag in effect for 2 years and a 5% annual event rate in the placebo group. The design, analysis, and conduct of the study are controlled by the Steering Committee of Principal Investigators and coordinated at the University of California, San Francisco. HERS is the largest trial of any intervention to reduce the risk of recurrent CHD events in women with heart disease and is the first controlled trial to seek evidence of the efficacy and safety of postmenopausal hormone therapy to prevent recurrent CHD events.
Collapse
Affiliation(s)
- D Grady
- Department of Epidemiology and Biostatistics, University of California, San Francisco, 94105, USA
| | | | | | | | | | | |
Collapse
|
31
|
Riggs B, O'Fallon W, Hodgson S, Chao E, Wahner H, Muhs J, Melton L. Clinical trial of fluoride in osteoporotic women: Extended observation and additional analyses. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/0169-6009(92)91660-b] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
32
|
Riggs B. Use caution when donating drugs, guidelines suggest. CMAJ 1990; 142:65-6. [PMID: 2293855 PMCID: PMC1451571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
|
33
|
Riggs B. As government well runs dry, public donations to hospitals become crucial. CMAJ 1988; 139:1193. [PMID: 3196996 PMCID: PMC1268500] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
|
34
|
Riggs B. Caring for seniors: "never do for them what they can do for themselves". CMAJ 1988; 139:552-3. [PMID: 3409144 PMCID: PMC1268221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
|
35
|
|
36
|
Riggs B, Jowsey J, Kelly PJ, Arnaud CD. Bone turnover-sex hormone-parathyroid hormone interrelationships in postmenopausal osteoporosis. Boll Soc Ital Biol Sper 1973; 49:732-7. [PMID: 4364781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
|