DOCSLIB.ORG

Ubiquitin Family Proteins and Their Relationship to the Proteasome: a Structural Perspective

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Ubiquitin Family Proteins and Their Relationship to the Proteasome: a Structural Perspective Biochimica et Biophysica Acta 1695 (2004) 73–87 http://www.elsevier.com/locate/bba Review Ubiquitin family proteins and their relationship to the proteasome: a structural perspective Kylie J. Waltersa, Amanda M. Gohb, Qinghua Wanga, Gerhard Wagnerc, Peter M. Howleyb,* aDepartment of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, United States bDepartment of Pathology, Harvard Medical School, Boston, MA 02115, United States cDepartment of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, United States Available online 26 October 2004 Abstract Many biological processes rely on targeted protein degradation, the dysregulation of which contributes to the pathogenesis of various diseases. Ubiquitin plays a well-established role in this process, in which the covalent attachment of polyubiquitin chains to protein substrates culminates in their degradation via the proteasome. The three-dimensional structural topology of ubiquitin is highly conserved as a domain found in a variety of proteins of diverse biological function. Some of these so-called bubiquitin family proteinsQ have recently been shown to bind components of the 26S proteasome via their ubiquitin-like domains, thus implicating proteasome activity in pathways other than protein degradation. In this chapter, we provide a structural perspective of how the ubiquitin family of proteins interacts with the proteasome. D 2004 Elsevier B.V. All rights reserved. Keywords: Protein degradation; Ubiquitin; Ubiquitin-like domain; Proteasome 1. Introduction A highly conserved ubiquitin structural fold is present in numerous eukaryotic proteins and has ancestral ties to the Ubiquitin-mediated protein degradation is one of the prokaryotic protein ThiS [18]. Ubiquitin family proteins have major mechanisms for controlled proteolysis, which is crucial been defined by their structural homology with ubiquitin and for many cellular events, including the control of life span of are divided into two families: type I ubiquitin-like proteins regulatory proteins, the removal of improperly folded and type II ubiquitin-like domain proteins. Like ubiquitin, proteins that would otherwise aggregate, and the production these proteins are involved in a variety of different biological of immunocompetent peptides [1–6]. The role of ubiquitin in pathways. Some ubiquitin-like domains have been found to degradation is its most extensively studied function: poly- bind proteasomal subunits, although the functional signifi- ubiquitin chains are covalently attached to proteins and serve cance of these interactions remains the subject of much as a signal for their recognition and degradation by the 26S speculation. In this chapter, we illustrate how the interactions proteasome [2]. Ubiquitin has also been found to be involved between ubiquitin family members and proteasomal subunits in protein trafficking [7–11], DNA repair [12–14], signaling may be characterized by NMR spectroscopy, and we discuss pathways [15], and transcription [16,17]. the implications of such interactions for proteasome activity. 2. The ubiquitin family of proteins Abbreviations: E6AP, E6-associated protein; hHR23a, human homolog A of Rad23; hPLIC-2, human proteasome ligase interaction component-2; 2.1. A prominent role for ubiquitin in targeted protein HSQC, heteronuclear single quantum coherence; NMR, nuclear magnetic degradation resonance; ppm, parts per million; S5a, subunit 5a; SUMO-1, small ubiquitin-related modifier-1 * Corresponding author. The best-characterized role of ubiquitin is in targeted E-mail address: [email protected] (P.M. Howley). protein degradation by the 26S proteasome, which consists 0167-4889/$ - see front matter D 2004 Elsevier B.V. All rights reserved. doi:10.1016/j.bbamcr.2004.10.005 74 K.J. Walters et al. / Biochimica et Biophysica Acta 1695 (2004) 73–87 of two 19S regulatory particles and a 20S core. Proteins be expressed during each transcription/translation cycle. The are posttranslationally modified by ubiquitin via an fusion proteins are subsequently separated into functional enzymatic cascade, which begins with the formation of a molecules by isopeptidase cleavage at the C-terminus, thioester bond between a ubiquitin-activating enzyme (E1) where there is usually a diglycine motif [23–26]. and the C-terminal glycine of ubiquitin. This activated SUMO-1 (Small Ubiquitin-related MOdifier) is a much ubiquitin is subsequently transferred to a ubiquitin- studied type I ubiquitin family protein. It is conserved conjugating enzyme (E2) [19–21]. An E3 ubiquitin ligase from yeast to mammals and its sequence is 18% identical then catalyzes the formation of an isopeptide bond to that of ubiquitin. The list of substrates for SUMO-1 is between ubiquitin and lysine residues of a specific target growing steadily and the effects of SUMO-1 conjugation protein, either by directly accepting the ubiquitin and are diverse. Sumoylation may affect the intracellular transferring it to the substrate, or by bringing the substrate localization of the proteins to which they are conjugated. into proximity with the E2–ubiquitin complex. This For example, the sumoylation of RanGAP1 targets it to process is repeated, with more ubiquitin moieties being the nuclear pore complex [27] and the attachment of covalently conjugated to those already in the nascent SUMO-1 to the PML protein (identified as a fusion polyubiquitin chain. These polyubiquitin chains are protein in promyelocytic leukemia patients) is crucial for recognized by the 19S regulatory complex of the 26S its localization to nuclear bodies [28]. The conjugation of proteasome and the proteins to which they are conjugated SUMO-1 to transcription factors may regulate their are degraded [22]. activity, as has been shown for c-Jun, p53, and c-Myb [29–31]. Sumoylation may also protect proteins from 2.2. Type I ubiquitin-like proteins degradation, as it does for InBa [32]. There is evidence for cross-talk between the ubiquitination and sumoylation The first class of ubiquitin family proteins, the type I machinery [14], the mechanism and functional signifi- ubiquitin-like proteins, are similar to ubiquitin: they can cance of which are still unclear. Interestingly, increased either exist freely or be covalently attached to other proteins levels of sumoylated proteins have been found to be via an enzymatic cascade (Fig. 1A). Like ubiquitin, they are associated with polyglutamine diseases such as Hunting- expressed as fusion products, allowing several moieties to ton’s disease [33]. Fig. 1. Schematic diagram illustrating the structural domains within several type I (A) and type II (B) ubiquitin family members. Proteins included are NEDD8; SUMO1, small ubiquitin-related modifier-1; FUBI, failure of ureteric bud invasion protein; UCRP, ubiquitin cross-reactive protein precursor; hHR23a, human homolog of Rad23-a; hHR23b, human homolog of Rad23-b; hPLIC-1, human proteasome ligase interaction component-1; hPLIC-2, human proteasome ligase interaction component-2; ubiquilin-3; A1Up, ataxin-1 ubiquitin-like interacting protein; NUB1, NEDD8 ultimate buster-1; BAG1, BCL-2 binding athanogene- 1 protein; Parkin; ElonginB; HERP, homocysteine-responsive endoplasmic reticulum-resident ubiquitin-like domain member 1 protein; OASL, 59-kDa2V-5V- oligoadenylate synthetase like protein; GdX, ubiquitin-like protein from chromosome Xq28; U7I3, ubiquitin conjugating enzyme 7 interacting protein 3; S3A1, splicing factor 3 subunit 1; BAT3, HLA-B-associated transcript 3; Uch14, ubiquitin carboxyl-terminal hydrolase 14. Ubiquitin-like and ubiquitin-associated domains are represented as UBL and UBA, respectively. Other identified functional domains within these proteins are also included as BAG, bcl-2-associated athanogene domain; COL, collagen-like domain; IBR, in between ring finger domains; PAP, polyA-related domain; ProR, proline-rich region; SYNTH, 2V-5V- oligoadenylate synthetase N-terminal region; SWAP, suppressor-of-white-apricot splicing regulator domain; UCH-1, ubiquitin carboxyl-terminal hydrolase family 1; UCH-2, ubiquitin carboxyl-terminal hydrolase family 2; XPC, XPC-binding domain; ZnF, zinc finger domain. K.J. Walters et al. / Biochimica et Biophysica Acta 1695 (2004) 73–87 75 Nedd8, also known as RUB (Related to Ubiquitin) in have also been shown to bind the E3 ubiquitin ligase yeast, is a type I ubiquitin family member that functions in E6AP [52,54]. These interactions suggest that the PLIC targeted protein degradation. The Nedd8 conjugation path- proteins are functionally linked to the ubiquitin–protea- way is conserved and essential in many eukaryotes, some pathway, which is further supported by reports that including Schizosaccharomyces cerevisiae, Arabidopsis, they regulate the stability of the GABAA receptor and of and humans, but notably not in Saccharomyces cerevisiae presenilin [55,56]. Regulation of the GABAA receptor is (S. cerevisiae) [34]. The only known substrates for Nedd8 important for inhibitory neurotransmission and mutations are cullins, which are a key component of the SCF in presenilin are associated with early-onset Alzheimer’s ubiquitin ligase complexes. Neddylation of the cullins is disease, thereby implicating the PLIC proteins in proper important in the regulation of SCF function. For example, nervous system function. In addition to its role in Nedd8 conjugation to Cul-1 activates ubiquitin-mediated ubiquitin-mediated protein degradation, Dsk2 has been proteolysis of p27 and
Load more

Recommended publications
  • A Computational Approach for Defining a Signature of Β-Cell Golgi Stress in Diabetes Mellitus
    Page 1 of 781 Diabetes A Computational Approach for Defining a Signature of β-Cell Golgi Stress in Diabetes Mellitus Robert N. Bone1,6,7, Olufunmilola Oyebamiji2, Sayali Talware2, Sharmila Selvaraj2, Preethi Krishnan3,6, Farooq Syed1,6,7, Huanmei Wu2, Carmella Evans-Molina 1,3,4,5,6,7,8* Departments of 1Pediatrics, 3Medicine, 4Anatomy, Cell Biology & Physiology, 5Biochemistry & Molecular Biology, the 6Center for Diabetes & Metabolic Diseases, and the 7Herman B. Wells Center for Pediatric Research, Indiana University School of Medicine, Indianapolis, IN 46202; 2Department of BioHealth Informatics, Indiana University-Purdue University Indianapolis, Indianapolis, IN, 46202; 8Roudebush VA Medical Center, Indianapolis, IN 46202. *Corresponding Author(s): Carmella Evans-Molina, MD, PhD ([email protected]) Indiana University School of Medicine, 635 Barnhill Drive, MS 2031A, Indianapolis, IN 46202, Telephone: (317) 274-4145, Fax (317) 274-4107 Running Title: Golgi Stress Response in Diabetes Word Count: 4358 Number of Figures: 6 Keywords: Golgi apparatus stress, Islets, β cell, Type 1 diabetes, Type 2 diabetes 1 Diabetes Publish Ahead of Print, published online August 20, 2020 Diabetes Page 2 of 781 ABSTRACT The Golgi apparatus (GA) is an important site of insulin processing and granule maturation, but whether GA organelle dysfunction and GA stress are present in the diabetic β-cell has not been tested. We utilized an informatics-based approach to develop a transcriptional signature of β-cell GA stress using existing RNA sequencing and microarray datasets generated using human islets from donors with diabetes and islets where type 1(T1D) and type 2 diabetes (T2D) had been modeled ex vivo. To narrow our results to GA-specific genes, we applied a filter set of 1,030 genes accepted as GA associated.
    [Show full text]
  • Characterization of the Cellular Network of Ubiquitin Conjugating and Ligating Enzymes Ewa Katarzyna Blaszczak
    Characterization of the cellular network of ubiquitin conjugating and ligating enzymes Ewa Katarzyna Blaszczak To cite this version: Ewa Katarzyna Blaszczak. Characterization of the cellular network of ubiquitin conjugating and ligating enzymes. Cellular Biology. Université Rennes 1, 2015. English. NNT : 2015REN1S116. tel-01547616 HAL Id: tel-01547616 https://tel.archives-ouvertes.fr/tel-01547616 Submitted on 27 Jun 2017 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. ANNÉE 2015 THÈSE / UNIVERSITÉ DE RENNES 1 sous le sceau de l’Université Européenne de Bretagne pour le grade de DOCTEUR DE L’UNIVERSITÉ DE RENNES 1 Mention : BIOLOGIE École doctorale Vie-Agro-Santé présentée par Ewa Katarzyna Blaszczak Préparée à l’unité de recherche UMR 6290, IGDR Institut de Génétique et Développement de Rennes Université Rennes 1 Thèse soutenue à Rennes le 26.06.2015 Characterization of devant le jury composé de : Aude ECHALIER-GLAZER the cellular network Maître de conférence University of Leicester / rapporteur of ubiquitin Lionel PINTARD Directeur de recherche
    [Show full text]
  • Oncoprotein MDM2 Is a Ubiquitin Ligase E3 for Tumor Suppressor P53
    View metadata,FEBS 19628 citation and similar papers at core.ac.uk FEBS Letters 420brought (1997) to you 25^27 by CORE provided by Elsevier - Publisher Connector Oncoprotein MDM2 is a ubiquitin ligase E3 for tumor suppressor p53 Reiko Honda, Hirofumi Tanaka, Hideyo Yasuda* School of Life Science, Tokyo University of Pharmacy and Life Science, Hachioji, 1432-1 Horinouchi, Tokyo 192-03, Japan Received 20 October 1997; revised version received 12 November 1997 the ubiquitin activating enzyme, E1, the ubiquitin conjugating Abstract The tumor suppressor p53 is degraded by the ubiquitin-proteasome system. p53 was polyubiquitinated in the enzyme, E2 and the ubiquitin ligase, E3. E1 is a common presence of E1, UbcH5 as E2 and MDM2 oncoprotein. A enzyme involved in all kinds of ubiquitination. The speci¢city ubiquitin molecule bound MDM2 through sulfhydroxy bond of the targeted protein is dependent on the E2 and E3 used in which is characteristic of ubiquitin ligase (E3)-ubiquitin binding. the reaction. The resultant ubiquitinated protein is degraded The cysteine residue in the carboxyl terminus of MDM2 was by proteasome. essential for the activity. These data suggest that the MDM2 protein, which is induced by p53, functions as a ubiquitin ligase, 2. Materials and methods E3, in human papillomavirus-uninfected cells which do not have E6 protein. 2.1. Expression of proteins z 1997 Federation of European Biochemical Societies. Human MDM2 [15], E6-AP [16], UbcH7 [17], E2-C/UbcH10 [18], EFP [19], cdc34 [20] and UbcH5 [21] cDNAs were obtained by RT- Key words: MDM2; p53; Ubiquitin ligase; E6AP; HECT PCR using RNA from HeLa S3 cells.
    [Show full text]
  • Cloning of the Human Homolog of the CDC34 Cell Cycle Gene by Complementation in Yeast SHARON E
    Proc. Natl. Acad. Sci. USA Vol. 90, pp. 10484-10488, November 1993 Genetics Cloning of the human homolog of the CDC34 cell cycle gene by complementation in yeast SHARON E. PLON*tt, KATHLEEN A. LEPPIG§, HONG-NHUNG Do*, AND MARK GROUDINE*¶ *Fred Hutchinson Cancer Research Center, Seattle, WA 98104; and Departments of tMedicine, §Pathology and fRadiation Oncology, University of Washington, Seattle, WA 98195 Communicated by Leland Hartwell, August 9, 1993 ABSTRACT In a screen designed to isolate human cDNAs During initial screening for human cDNAs that would that complement a yeast G2 phase checkpoint mutation (mecl), complement the mecl checkpoint mutation, we obtained a we isolated a cDNA homologous to the Saccharomyces cerevi- partially active cDNA that further analysis reveals is the siae CDC34 gene. The human CDC34 cDNA can functionally human homolog of S. cerevisiae CDC34. We report here the substitute for the yeast CDC34 gene and represents a mam- cloning and functional and physical characterization of this malian homolog ofthe group ofyeast genes required for the late human gene. 11 G- S phase transition. The human CDC34 gene is expressed in multiple cell lines as a unique species and Southern blot MATERIALS AND METHODS analysis reveals evidence for a single gene that is highly conserved in higher eukaryotes. The human gene is located on Yeast and Bacterial Strains. The S. cerevisiae strains de- the far telomeric region of 19p13.3 in a location that defmes a scribed in these experiments were isogenic with A364a. region of homology between human chromosome 19p and Source of the strain other than this laboratory are indicated: mouse chromosome 11.
    [Show full text]
  • Protein Engineering of a Ubiquitin-Variant Inhibitor of APC/C Identifies a Cryptic K48 Ubiquitin Chain Binding Site
    Protein engineering of a ubiquitin-variant inhibitor of APC/C identifies a cryptic K48 ubiquitin chain binding site Edmond R. Watsona,b, Christy R. R. Gracea, Wei Zhangc,d,2, Darcie J. Millera, Iain F. Davidsone, J. Rajan Prabub, Shanshan Yua, Derek L. Bolhuisf, Elizaveta T. Kulkof, Ronnald Vollrathb, David Haselbache,g, Holger Starkg, Jan-Michael Peterse,h, Nicholas G. Browna,f, Sachdev S. Sidhuc,1, and Brenda A. Schulmana,b,1 aDepartment of Structural Biology, St. Jude Children’s Research Hospital, Memphis, TN 38105; bDepartment of Molecular Machines and Signaling, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany; cDonnelly Centre for Cellular and Biomolecular Research, Banting and Best Department of Medical Research, University of Toronto, Toronto, ON, Canada M5S3E1; dDepartment of Molecular Genetics, University of Toronto, Toronto, ON, Canada M5S3E1; eResearch Institute of Molecular Pathology, Vienna BioCenter, 1030 Vienna, Austria; fDepartment of Pharmacology and Lineberger Comprehensive Cancer Center, University of North Carolina School of Medicine, Chapel Hill, NC 27599; gMax Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany; and hMedical University of Vienna, 1090 Vienna, Austria Contributed by Brenda A. Schulman, June 24, 2019 (sent for review February 19, 2019; reviewed by Kylie Walters and Hao Wu) Ubiquitin (Ub)-mediated proteolysis is a fundamental mechanism the type of catalytic domain. E3s harboring “HECT” and “RBR” used by eukaryotic cells to maintain homeostasis and protein catalytic domains promote ubiquitylation through 2-step reac- quality, and to control timing in biological processes. Two essential tions involving formation of a thioester-linked intermediate be- aspects of Ub regulation are conjugation through E1-E2-E3 enzy- tween the E3 and Ub’s C terminus: First, Ub is transferred from matic cascades and recognition by Ub-binding domains.
    [Show full text]
  • Kinase SH3 NH2 Cdc42
    A Dissertation The E3 Ligase CHIP Mediates Ubiquitination and Degradation of Mixed Lineage Kinase 3 and Mixed Lineage Kinase 4 Beta by Natalya A. Blessing Submitted to the Graduate Faculty as partial fulfillment of the requirements for the Doctor of Philosophy Degree in Biology _________________________________________ Dr. Deborah Chadee, Committee Chair _________________________________________ Dr. Richard Komuniecki, Committee Member _________________________________________ Dr. Malathi Krishnamurthy, Committee Member _________________________________________ Dr. Frank Pizza, Committee Member _________________________________________ Dr. Don Ronning, Committee Member _________________________________________ Dr. Patricia R. Komuniecki, Dean College of Graduate Studies The University of Toledo May 2015 Copyright 2015, Natalya A. Blessing This document is copyrighted material. Under copyright law, no parts of this document may be reproduced without the expressed permission of the author. An Abstract of The E3 Ligase CHIP Mediates Ubiquitination and Degradation of Mixed Lineage Kinase 3 and Mixed Lineage Kinase 4 Beta by Natalya Blessing Submitted to the Graduate Faculty as partial fulfillment of the requirements for the Doctor of Philosophy Degree in Biology The University of Toledo May 2015 The mixed lineage kinases (MLKs) are serine/threonine mitogen-activated protein kinase kinase kinases (MAP3Ks) that modulate the activities of extracellular signal- regulated kinase, c-Jun N-terminal kinase, and p38 signaling pathways. MLK3 plays a pivotal role in cell invasion, tumorigenesis and metastasis. Wild type MLK4 negatively regulates MAPK signaling by possibly inhibiting MLK3 activation, while mutant MLK4 plays in important role in driving colorectal cancer and glioblastomal tumorigenesis (Martini et al., 2013). The mechanisms by which MLK3 and MLK4 protein levels are regulated in cells are unknown. The carboxyl terminus of HSC-70 interacting protein (CHIP) is a U-box E3 ubiquitin ligase that regulates cytosolic protein degradation in response to stress.
    [Show full text]
  • Engineering a Synthetic P53-Mdm2 Network in Budding Yeast
    Dissertation Submitted to the Combined Faculties for the Natural Sciences and for Mathematics Of the Ruperto-Carola University of Heidelberg, Germany for the degree of Doctor of Natural Sciences Engineering a synthetic p53-Mdm2 network in budding yeast presented by Diplom: Barbara Di Ventura Born in: Latina, Italia 2006 Dissertation Submitted to the Combined Faculties for the Natural Sciences and for Mathematics Of the Ruperto-Carola University of Heidelberg, Germany for the degree of Doctor of Natural Sciences presented by Diplom: Barbara Di Ventura Born in: Latina, Italia Engineering a synthetic p53-Mdm2 network in budding yeast Referees: Prof. Dr. Michael Knop Prof. Dr. Karsten Rippe A mamma, papa’ e Chicca "Experience is the name everyone gives to their mistake" Oscar Wilde Acknowledgments If I am here, writing the acknowledgements section in my phd thesis, I owe it first of all to my boss, Luis. I am grateful that he wasn’t discouraged with the idea of getting an engineer to work in his lab. On the opposite, he often told me that it was an advantage to be naïve and ask the simplest questions. He offered me the opportunity to do my own experiments, to make many mistakes, to develop my own way to do research. Most of all, he has always comforted me in moments of discouragement, assuring me that lack of results or experiments gone wrong are an inevitable feature of research. Luis, your positive attitude, your extreme generosity, your humanity, make of you an example to follow and give me hope that one can be a scientist and lead a happy life at the same time! Among the many people who have helped me with the basics of molecular biology and that have patiently listened to me talking about the many doubts or troubles related to my project, I first would like to thank Massimiliano.
    [Show full text]
  • UC Irvine UC Irvine Electronic Theses and Dissertations
    UC Irvine UC Irvine Electronic Theses and Dissertations Title Investigating Protein Complex Dynamics: Analysis of Cullin-Ring Ligase Machinery through Development of Quantitative Cross-linking Mass Spectrometry Strategies Permalink https://escholarship.org/uc/item/6164k1z6 Author Yu, Clinton Publication Date 2017 Supplemental Material https://escholarship.org/uc/item/6164k1z6#supplemental Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA, IRVINE Investigating Protein Complex Dynamics: Analysis of Cullin-Ring Ligase Machinery through Development of Quantitative Cross-linking Mass Spectrometry Strategies DISSERTATION Submitted in partial satisfaction of the requirements for the degree of DOCTOR OF PHILOSOPHY In Biological Sciences By Clinton Yu Dissertation Committee: Professor Lan Huang, Chair Professor Todd Holmes Professor Rongsheng Jin Professor Feng Qiao 2017 TABLE OF CONTENTS LIST OF FIGURES ...................................................................................................................... v LIST OF TABLES ...................................................................................................................... vii ACRONYMS & SYMBOLS ..................................................................................................... viii ACKNOWLEDGMENTS ........................................................................................................... ix CURRICULUM VITAE ..............................................................................................................
    [Show full text]
  • Comparative Analysis of the Ubiquitin-Proteasome System in Homo Sapiens and Saccharomyces Cerevisiae
    Comparative Analysis of the Ubiquitin-proteasome system in Homo sapiens and Saccharomyces cerevisiae Inaugural-Dissertation zur Erlangung des Doktorgrades der Mathematisch-Naturwissenschaftlichen Fakultät der Universität zu Köln vorgelegt von Hartmut Scheel aus Rheinbach Köln, 2005 Berichterstatter: Prof. Dr. R. Jürgen Dohmen Prof. Dr. Thomas Langer Dr. Kay Hofmann Tag der mündlichen Prüfung: 18.07.2005 Zusammenfassung I Zusammenfassung Das Ubiquitin-Proteasom System (UPS) stellt den wichtigsten Abbauweg für intrazelluläre Proteine in eukaryotischen Zellen dar. Das abzubauende Protein wird zunächst über eine Enzym-Kaskade mit einer kovalent gebundenen Ubiquitinkette markiert. Anschließend wird das konjugierte Substrat vom Proteasom erkannt und proteolytisch gespalten. Ubiquitin besitzt eine Reihe von Homologen, die ebenfalls posttranslational an Proteine gekoppelt werden können, wie z.B. SUMO und NEDD8. Die hierbei verwendeten Aktivierungs- und Konjugations-Kaskaden sind vollständig analog zu der des Ubiquitin- Systems. Es ist charakteristisch für das UPS, daß sich die Vielzahl der daran beteiligten Proteine aus nur wenigen Proteinfamilien rekrutiert, die durch gemeinsame, funktionale Homologiedomänen gekennzeichnet sind. Einige dieser funktionalen Domänen sind auch in den Modifikations-Systemen der Ubiquitin-Homologen zu finden, jedoch verfügen diese Systeme zusätzlich über spezifische Domänentypen. Homologiedomänen lassen sich als mathematische Modelle in Form von Domänen- deskriptoren (Profile) beschreiben. Diese Deskriptoren können wiederum dazu verwendet werden, mit Hilfe geeigneter Verfahren eine gegebene Proteinsequenz auf das Vorliegen von entsprechenden Homologiedomänen zu untersuchen. Da die im UPS involvierten Homologie- domänen fast ausschließlich auf dieses System und seine Analoga beschränkt sind, können domänen-spezifische Profile zur Katalogisierung der UPS-relevanten Proteine einer Spezies verwendet werden. Auf dieser Basis können dann die entsprechenden UPS-Repertoires verschiedener Spezies miteinander verglichen werden.
    [Show full text]
  • Apoptosis Product List
    Tools for assessing cell events Apoptosis, cell cycle and cell proliferation Product list The balance of cell proliferation and apoptosis is important In addition to flow cytometry products, BD Life Sciences carries for both development and normal tissue homeostasis. Cell a broad portfolio of reagents for determination and detection proliferation is an increase in the number of cells as a result of of apoptotic and proliferative events by immunohistochemistry, growth and division. Cell proliferation is regulated by the cell cell imaging, and Western blot. cycle, which is divided into a series of phases. Apoptosis, or As part of our commitment to maximize scientific results, programmed cell death, results in controlled self-destruction. BD Life Sciences provides a variety of tools to assist customers Several methods have been developed to assess apoptosis, in their experimental setup and analysis. These include a cell cycle, and cell proliferation. BD Life Sciences offers a decision tree to guide in the selection of the most suitable complete portfolio of reagents and tools to allow exploration methods for a specific study. of the cellular features of these processes. BD Life Sciences carries high-quality reagents in the latest Over the years, multicolor flow cytometry has become essential formats to examine cell cycle, proliferation, and apoptosis in the study of apoptosis, cell cycle, and cell proliferation. across a variety of platforms, in applications from basic Success of the technology results from its ability to monitor research to drug screening. these processes along with other cellular events, such as protein phosphorylation or cytokine secretion, within heterogeneous cell populations.
    [Show full text]
  • The Loop-Less Cdc34 E2 Mutant Defective in Polyubiquitination In
    Lass et al. Cell Division 2011, 6:7 http://www.celldiv.com/content/6/1/7 RESEARCH Open Access The loop-less tmCdc34 E2 mutant defective in polyubiquitination in vitro and in vivo supports yeast growth in a manner dependent on Ubp14 and Cka2 Agnieszka Lass1†, Ross Cocklin2†, Kenneth M Scaglione1,3, Michael Skowyra1,4, Sergey Korolev1, Mark Goebl2* and Dorota Skowyra1* Abstract Background: The S73/S97/loop motif is a hallmark of the Cdc34 family of E2 ubiquitin-conjugating enzymes that together with the SCF E3 ubiquitin ligases promote degradation of proteins involved in cell cycle and growth regulation. The inability of the loop-less Δ12Cdc34 mutant to support growth was linked to its inability to catalyze polyubiquitination. However, the loop-less triple mutant (tm) Cdc34, which not only lacks the loop but also contains the S73K and S97D substitutions typical of the K73/D97/no loop motif present in other E2s, supports growth. Whether tmCdc34 supports growth despite defective polyubiquitination, or the S73K and S97D substitutions, directly or indirectly, correct the defect caused by the loop absence, are unknown. Results: tmCdc34 supports yeast viability with normal cell size and cell cycle profile despite producing fewer polyubiquitin conjugates in vivo and in vitro.Thein vitro defect in Sic1 substrate polyubiquitination is similar to the defect observed in reactions with Δ12Cdc34 that cannot support growth. The synthesis of free polyubiquitin by tmCdc34 is activated only modestly and in a manner dependent on substrate recruitment to SCFCdc4. Phosphorylation of C-terminal serines in tmCdc34 by Cka2 kinase prevents the synthesis of free polyubiquitin chains, likely by promoting their attachment to substrate.
    [Show full text]
  • Genome-Wide Identification of CDC34 That Stabilizes EGFR and Promotes Lung Carcinogenesis
    bioRxiv preprint doi: https://doi.org/10.1101/255844; this version posted January 29, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Genome-wide identification of CDC34 that stabilizes EGFR and promotes lung carcinogenesis Running title: CDC34 stabilizes EGFR in lung cancer Xin-Chun Zhao1,2, Gui-Zhen Wang1, Yong-Chun Zhou3, Liang Ma1, Jie Liu1, Chen Zhang1, Da- Lin Zhang1, San-Hui Gao1, Li-Wei Qu1, Bin Zhang4, Chang-Li Wang4, Yun-Chao Huang3, Liang Chen5, Guang-Biao Zhou1 1School of Life Sciences, University of Science and Technology of China, Hefei 230026; 2State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences & University of Chinese Academy of Sciences, Beijing 100101; 3Department of Thoracic Surgery, the Third Affiliated Hospital of Kunming Medical University, Kunming 650106; 4Department of Lung Cancer, Tianjin Lung Cancer Center, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin’s Clinical Research Center for Cancer, Tianjin Medical University Cancer Institute and Hospital, Tianjin 300060; 5Institute of Life and Health Engineering, Jinan University, Guangzhou 510632, China # Correspondence to: Guang-Biao Zhou, MD, Ph.D, Institute of Zoology, Chinese Academy of Sciences, 1 West Beichen Road, Beijing 100101, China. Tel: 86-10-64807951; Email: [email protected]. 1 bioRxiv preprint doi: https://doi.org/10.1101/255844; this version posted January 29, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved.
    [Show full text]