1
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Dulloo I, Tellier M, Levet C, Chikh A, Zhang B, Blaydon DC, Webb CM, Kelsell DP, Freeman M. Cleavage of the pseudoprotease iRhom2 by the signal peptidase complex reveals an ER-to-nucleus signaling pathway. Mol Cell 2024; 84:277-292.e9. [PMID: 38183983 DOI: 10.1016/j.molcel.2023.12.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 09/18/2023] [Accepted: 12/08/2023] [Indexed: 01/08/2024]
Abstract
iRhoms are pseudoprotease members of the rhomboid-like superfamily and are cardinal regulators of inflammatory and growth factor signaling; they function primarily by recognizing transmembrane domains of their clients. Here, we report a mechanistically distinct nuclear function of iRhoms, showing that both human and mouse iRhom2 are non-canonical substrates of signal peptidase complex (SPC), the protease that removes signal peptides from secreted proteins. Cleavage of iRhom2 generates an N-terminal fragment that enters the nucleus and modifies the transcriptome, in part by binding C-terminal binding proteins (CtBPs). The biological significance of nuclear iRhom2 is indicated by elevated levels in skin biopsies of patients with psoriasis, tylosis with oesophageal cancer (TOC), and non-epidermolytic palmoplantar keratoderma (NEPPK); increased iRhom2 cleavage in a keratinocyte model of psoriasis; and nuclear iRhom2 promoting proliferation of keratinocytes. Overall, this work identifies an unexpected SPC-dependent ER-to-nucleus signaling pathway and demonstrates that iRhoms can mediate nuclear signaling.
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Affiliation(s)
- Iqbal Dulloo
- Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
| | - Michael Tellier
- Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Clémence Levet
- Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Anissa Chikh
- Blizard Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, Newark Street, London E1 2AT, UK
| | - Boyan Zhang
- Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Diana C Blaydon
- Blizard Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, Newark Street, London E1 2AT, UK
| | - Catherine M Webb
- Blizard Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, Newark Street, London E1 2AT, UK
| | - David P Kelsell
- Blizard Institute, Faculty of Medicine and Dentistry, Queen Mary University of London, Newark Street, London E1 2AT, UK
| | - Matthew Freeman
- Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
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2
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Bhaduri S, Scott NA, Neal SE. The Role of the Rhomboid Superfamily in ER Protein Quality Control: From Mechanisms and Functions to Diseases. Cold Spring Harb Perspect Biol 2023; 15:a041248. [PMID: 35940905 PMCID: PMC9899648 DOI: 10.1101/cshperspect.a041248] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The endoplasmic reticulum (ER) is an essential organelle in eukaryotic cells and is a major site for protein folding, modification, and lipid synthesis. Perturbations within the ER, such as protein misfolding and high demand for protein folding, lead to dysregulation of the ER protein quality control network and ER stress. Recently, the rhomboid superfamily has emerged as a critical player in ER protein quality control because it has diverse cellular functions, including ER-associated degradation (ERAD), endosome Golgi-associated degradation (EGAD), and ER preemptive quality control (ERpQC). This breadth of function both illustrates the importance of the rhomboid superfamily in health and diseases and emphasizes the necessity of understanding their mechanisms of action. Because dysregulation of rhomboid proteins has been implicated in various diseases, such as neurological disorders and cancers, they represent promising potential therapeutic drug targets. This review provides a comprehensive account of the various roles of rhomboid proteins in the context of ER protein quality control and discusses their significance in health and disease.
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Affiliation(s)
- Satarupa Bhaduri
- School of Biological Sciences, the Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093, USA
| | - Nicola A Scott
- School of Biological Sciences, the Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093, USA
| | - Sonya E Neal
- School of Biological Sciences, the Section of Cell and Developmental Biology, University of California San Diego, La Jolla, California 92093, USA
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3
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Lastun VL, Levet C, Freeman M. The mammalian rhomboid protein RHBDL4 protects against endoplasmic reticulum stress by regulating the morphology and distribution of ER sheets. J Biol Chem 2022; 298:101935. [PMID: 35436469 PMCID: PMC9136127 DOI: 10.1016/j.jbc.2022.101935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 03/24/2022] [Accepted: 03/28/2022] [Indexed: 11/16/2022] Open
Abstract
In metazoans, the architecture of the endoplasmic reticulum (ER) differs between cell types and undergoes major changes throughout the cell cycle and according to physiological needs. Although much is known about how the different ER morphologies are generated and maintained, especially ER tubules, how context-dependent changes in ER shape and distribution are regulated and the factors involved are less well characterized, as are the factors that contribute to the positioning of the ER within the cell. By overexpression and KO experiments, we show that the levels of RHBDL4, an ER-resident rhomboid protease, modulate the shape and distribution of the ER, especially during conditions that require rapid changes in the ER sheet distribution, such as ER stress. We demonstrate that RHBDL4 interacts with cytoskeleton-linking membrane protein 63 (CLIMP-63), a protein involved in ER sheet stabilization, as well as with the cytoskeleton. Furthermore, we found that mice lacking RHBDL4 are sensitive to ER stress and develop liver steatosis, a phenotype associated with unresolved ER stress. Taken together, these data suggest a new physiological role for RHBDL4 and also imply that this function does not require its enzymatic activity.
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4
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iRhom pseudoproteases regulate ER stress-induced cell death through IP 3 receptors and BCL-2. Nat Commun 2022; 13:1257. [PMID: 35273168 PMCID: PMC8913617 DOI: 10.1038/s41467-022-28930-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 02/17/2022] [Indexed: 12/13/2022] Open
Abstract
The folding capacity of membrane and secretory proteins in the endoplasmic reticulum (ER) can be challenged by physiological and pathological perturbations, causing ER stress. If unresolved, this leads to cell death. We report a role for iRhom pseudoproteases in controlling apoptosis due to persistent ER stress. Loss of iRhoms causes cells to be resistant to ER stress-induced apoptosis. iRhom1 and iRhom2 interact with IP3 receptors, critical mediators of intracellular Ca2+ signalling, and regulate ER stress-induced transport of Ca2+ into mitochondria, a primary trigger of mitochondrial membrane depolarisation and cell death. iRhoms also bind to the anti-apoptotic regulator BCL-2, attenuating the inhibitory interaction between BCL-2 and IP3 receptors, which promotes ER Ca2+ release. The discovery of the participation of iRhoms in the control of ER stress-induced cell death further extends their potential pathological significance to include diseases dependent on protein misfolding and aggregation. Cells that cannot cope with persistent endoplasmic reticulum stress will die. Here, the authors show that iRhom pseudoproteases regulate cell death by modulating the ability of BCL-2 to inhibit calcium flow through IP3R channels.
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5
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Nejatfard A, Wauer N, Bhaduri S, Conn A, Gourkanti S, Singh N, Kuo T, Kandel R, Amaro RE, Neal SE. Derlin rhomboid pseudoproteases employ substrate engagement and lipid distortion to enable the retrotranslocation of ERAD membrane substrates. Cell Rep 2021; 37:109840. [PMID: 34686332 PMCID: PMC8641752 DOI: 10.1016/j.celrep.2021.109840] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Revised: 07/19/2021] [Accepted: 09/27/2021] [Indexed: 01/13/2023] Open
Abstract
Nearly one-third of proteins are initially targeted to the endoplasmic reticulum (ER) membrane, where they are correctly folded and then delivered to their final cellular destinations. To prevent the accumulation of misfolded membrane proteins, ER-associated degradation (ERAD) moves these clients from the ER membrane to the cytosol, a process known as retrotranslocation. Our recent work in Saccharomyces cerevisiae reveals a derlin rhomboid pseudoprotease, Dfm1, is involved in the retrotranslocation of ubiquitinated ERAD membrane substrates. In this study, we identify conserved residues of Dfm1 that are critical for retrotranslocation. We find several retrotranslocation-deficient Loop 1 mutants that display impaired binding to membrane substrates. Furthermore, Dfm1 possesses lipid thinning function to facilitate in the removal of ER membrane substrates, and this feature is conserved in its human homolog, Derlin-1, further implicating that derlin-mediated retrotranslocation is a well-conserved process.
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Affiliation(s)
- Anahita Nejatfard
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, USA
| | - Nicholas Wauer
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
| | - Satarupa Bhaduri
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, USA
| | - Adam Conn
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, USA
| | - Saroj Gourkanti
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, USA
| | - Narinderbir Singh
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, USA
| | - Tiffany Kuo
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, USA
| | - Rachel Kandel
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, USA
| | - Rommie E Amaro
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
| | - Sonya E Neal
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, USA.
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6
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Adrain C, Cavadas M. The complex life of rhomboid pseudoproteases. FEBS J 2020; 287:4261-4283. [DOI: 10.1111/febs.15548] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/18/2020] [Accepted: 08/31/2020] [Indexed: 02/06/2023]
Affiliation(s)
- Colin Adrain
- Instituto Gulbenkian de Ciência (IGC) Oeiras Portugal
- Centre for Cancer Research and Cell Biology Queen's University Belfast UK
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7
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Kandel RR, Neal SE. The role of rhomboid superfamily members in protein homeostasis: Mechanistic insight and physiological implications. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2020; 1867:118793. [PMID: 32645330 PMCID: PMC7434706 DOI: 10.1016/j.bbamcr.2020.118793] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 05/30/2020] [Accepted: 07/01/2020] [Indexed: 12/11/2022]
Abstract
Cells are equipped with protein quality control pathways in order to maintain a healthy proteome; a process known as protein homeostasis. Dysfunction in protein homeostasis leads to the development of many diseases that are associated with proteinopathies. Recently, the rhomboid superfamily has attracted much attention concerning their involvement in protein homeostasis. While their functional role has become much clearer in the last few years, their systemic significance in mammals remains elusive. Here we delineate the current knowledge of rhomboids in protein quality control and how these functions are integrated at the organismal level.
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Affiliation(s)
- Rachel R Kandel
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, United States of America
| | - Sonya E Neal
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California San Diego, La Jolla, CA 92093, United States of America.
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8
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Signal Peptide Peptidase-Type Proteases: Versatile Regulators with Functions Ranging from Limited Proteolysis to Protein Degradation. J Mol Biol 2020; 432:5063-5078. [DOI: 10.1016/j.jmb.2020.05.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/02/2020] [Accepted: 05/19/2020] [Indexed: 12/15/2022]
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9
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Adamiec M, Misztal L, Kasprowicz-Maluśki A, Luciński R. EGY3: homologue of S2P protease located in chloroplasts. PLANT BIOLOGY (STUTTGART, GERMANY) 2020; 22:735-743. [PMID: 31886945 DOI: 10.1111/plb.13087] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 12/16/2019] [Indexed: 06/10/2023]
Abstract
The EGY3 protein is a homologue of site-2 proteases, which are intramembrane zinc metalloproteases. EGY3 itself lacks proteolytic activity due to the absence of a zinc-binding motif. Plentiful evidence indicates that such intramembrane 'pseudoproteases' play significant roles in many diverse processes occurring within the cell. However, the physiological functions of EGY3, as well as its subcellular localization, remain unknown. The subcellular localization of EGY3 protein was investigated using Arabidopsis thaliana protoplasts transformed with EGY3-GFP fusion protein, and immunoblot experiments using the total leaf protein extract, as well as highly purified chloroplasts and fractions of stroma, envelope and thylakoid membrane proteins. The physiological role of EGY3 was studied using two A. thaliana mutant lines devoid of EGY3 protein. Chlorophyll a fluorescence measurement was performed and the egy3 mutant sensitivity to photoinhibition was investigated. Additionally, the abundance of thylakoid membrane complexes was established using blue native gel electrophoresis. We present experimental evidence for thylakoid membrane localization of the EGY3 protein. We show that egy3 mutants display increased value of the non-photochemical quenching parameter and significantly slower recovery rate after photoinhibitory treatment. This was associated with a decrease in the level of proteases involved in photosystem II recovery, Deg1 and FtsH2/8.
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Affiliation(s)
- M Adamiec
- Department of Plant Physiology, Faculty of Biology, Institute of Experimental Biology, Adam Mickiewicz University in Poznań, Poznań, Poland
| | - L Misztal
- Department of Plant Physiology, Faculty of Biology, Institute of Experimental Biology, Adam Mickiewicz University in Poznań, Poznań, Poland
| | - A Kasprowicz-Maluśki
- Department of Molecular and Cellular Biology, Faculty of Biology, Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University in Poznań, Poznań, Poland
| | - R Luciński
- Department of Plant Physiology, Faculty of Biology, Institute of Experimental Biology, Adam Mickiewicz University in Poznań, Poznań, Poland
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10
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Abstract
Rhomboid intramembrane serine proteases are present in all kingdoms of life, but as we do not know their substrates in many species, it remains puzzling why rhomboids are among the most-conserved integral membrane proteins. Two new studies in The EMBO Journal by Began et al and Liu et al now link bacterial rhomboid proteases to membrane protein degradation, showing striking similarities to what is known about eukaryotic rhomboid family proteins, thus pointing toward a conserved membrane surveillance mechanism.
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Affiliation(s)
- Julia D Knopf
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Marius K Lemberg
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
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11
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Dulloo I, Muliyil S, Freeman M. The molecular, cellular and pathophysiological roles of iRhom pseudoproteases. Open Biol 2020; 9:190003. [PMID: 30890028 PMCID: PMC6451368 DOI: 10.1098/rsob.190003] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
iRhom proteins are catalytically inactive relatives of rhomboid intramembrane proteases. There is a rapidly growing body of evidence that these pseudoenzymes have a central function in regulating inflammatory and growth factor signalling and consequent roles in many diseases. iRhom pseudoproteases have evolved new domains from their proteolytic ancestors, which are integral to their modular regulation and functions. Although we cannot yet conclude the full extent of their molecular and cellular mechanisms, there is a clearly emerging theme that they regulate the stability and trafficking of other membrane proteins. In the best understood case, iRhoms act as regulatory cofactors of the ADAM17 protease, controlling its function of shedding cytokines and growth factors. It seems likely that as the involvement of iRhoms in human diseases is increasingly recognized, they will become the focus of pharmaceutical interest, and here we discuss what is known about their molecular mechanisms and relevance in known pathologies.
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Affiliation(s)
- Iqbal Dulloo
- Dunn School of Pathology, University of Oxford , South Parks Road, Oxford OX1 3RE , UK
| | - Sonia Muliyil
- Dunn School of Pathology, University of Oxford , South Parks Road, Oxford OX1 3RE , UK
| | - Matthew Freeman
- Dunn School of Pathology, University of Oxford , South Parks Road, Oxford OX1 3RE , UK
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12
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Zaru R, Magrane M, Orchard S. Challenges in the annotation of pseudoenzymes in databases: the UniProtKB approach. FEBS J 2019; 287:4114-4127. [PMID: 31618524 DOI: 10.1111/febs.15100] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/27/2019] [Accepted: 10/15/2019] [Indexed: 12/14/2022]
Abstract
The universal protein knowledgebase (UniProtKB) collects and centralises functional information on proteins across a wide range of species. In addition to the functional information added to all protein entries, for enzymes, which represent 20-40% of most proteomes, UniProtKB provides additional information about Enzyme Commission classification, catalytic activity, cofactors, enzyme regulation, kinetics and pathways, all based on critical assessment of published experimental data. Computer-based analysis and structural data are used to enrich the annotation of the sequence through the identification of active sites and binding sites. While the annotation of enzymes is well-defined, the curation of pseudoenzymes in UniProtKB has highlighted some challenges: how to identify them, how to assess their lack of catalytic activity, how to annotate their lack of catalytic activity in a consistent way and how much can be inferred and propagated from experimental data obtained from other species. Through various examples, we illustrate some of these issues and discuss some of the changes we propose to enhance the annotation and discovery of pseudoenzymes. Ultimately, improving the curation of pseudoenzymes will provide the scientific community with a comprehensive resource for pseudoenzymes, which in turn will lead to a better understanding of the evolution of these molecules, the aetiology of related diseases and the development of drugs.
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Affiliation(s)
- Rossana Zaru
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Hinxton, Cambridge, UK
| | - Michele Magrane
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Hinxton, Cambridge, UK
| | - Sandra Orchard
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Hinxton, Cambridge, UK
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- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Hinxton, Cambridge, UK.,SIB Swiss Institute of Bioinformatics, Centre Medical Universitaire, Geneva, Switzerland.,Protein Information Resource, Georgetown University Medical Center, Washington, DC, USA.,Protein Information Resource, University of Delaware, Newark, DE, USA
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13
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Avci D, Lemberg MK. Membrane Protein Dislocation by the Rhomboid Pseudoprotease Dfm1: No Pore Needed? Mol Cell 2018; 69:161-162. [PMID: 29351840 DOI: 10.1016/j.molcel.2017.12.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Defective ER-resident membrane proteins need to be ejected into the cytoplasm in order to be degraded by the proteasome, but the exact mechanism remains unclear. In this issue of Molecular Cell, Neal et al. (2018) reveal that the rhomboid pseudoprotease Dfm1 defines the central ERAD component for membrane protein dislocation.
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Affiliation(s)
- Dönem Avci
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany
| | - Marius K Lemberg
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Im Neuenheimer Feld 282, 69120 Heidelberg, Germany.
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14
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Mechanisms of receptor shedding in platelets. Blood 2018; 132:2535-2545. [DOI: 10.1182/blood-2018-03-742668] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 10/12/2018] [Indexed: 02/07/2023] Open
Abstract
Abstract
The ability to upregulate and downregulate surface-exposed proteins and receptors is a powerful process that allows a cell to instantly respond to its microenvironment. In particular, mobile cells in the bloodstream must rapidly react to conditions where infection or inflammation are detected, and become proadhesive, phagocytic, and/or procoagulant. Platelets are one such blood cell that must rapidly acquire and manage proadhesive and procoagulant properties in order to execute their primary function in hemostasis. The regulation of platelet membrane properties is achieved via several mechanisms, one of which involves the controlled metalloproteolytic release of adhesion receptors and other proteins from the platelet surface. Proteolysis effectively lowers receptor density and reduces the reactivity of platelets, and is a mechanism to control robust platelet activation. Recent research has also established clear links between levels of platelet receptors and platelet lifespan. In this review, we will discuss the current knowledge of metalloproteolytic receptor regulation in the vasculature with emphasis on the platelet receptor system to highlight how receptor density can influence both platelet function and platelet survival.
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15
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Recinto SJ, Paschkowsky S, Munter LM. An alternative processing pathway of APP reveals two distinct cleavage modes for rhomboid protease RHBDL4. Biol Chem 2018; 399:1399-1408. [DOI: 10.1515/hsz-2018-0259] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 08/28/2018] [Indexed: 02/02/2023]
Abstract
AbstractSince the first genetic description of a rhomboid inDrosophila melanogaster, tremendous efforts have been geared towards elucidating the proteolytic mechanism of this particular class of intramembrane proteases. In particular, mammalian rhomboid proteases sparked our interest and we aimed to investigate the human homologue RHBDL4. In light of our recent finding of the amyloid precursor protein (APP) family as efficient substrates of RHBDL4, we were enticed to further study the specific proteolytic mechanism of this enzyme by comparing cleavage patterns of wild type APP and APP TMS chimeras. Here, we demonstrate that the introduction of positively charged amino acid residues in the TMS redirects the RHBDL4-mediated cleavage of APP from its ectodomain closer towards the TMS, possibly inducing an ER-associated degradation (ERAD) of the substrate. In addition, we concluded that the cytoplasmic tail and proposed palmitoylation sites in the ectodomain of APP are not essential for the RHBDL4-mediated APP processing. In summary, our previously identified APP ectodomain cleavages by RHBDL4 are a subsidiary mechanism to the proposed RHBDL4-mediated ERAD of substrates likely through a single cleavage near or within the TMS.
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16
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Li J, Bai TR, Gao S, Zhou Z, Peng XM, Zhang LS, Dou DL, Zhang ZS, Li LY. Human rhomboid family-1 modulates clathrin coated vesicle-dependent pro-transforming growth factor α membrane trafficking to promote breast cancer progression. EBioMedicine 2018; 36:229-240. [PMID: 30279141 PMCID: PMC6197618 DOI: 10.1016/j.ebiom.2018.09.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 09/13/2018] [Accepted: 09/20/2018] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Epidermal growth factor receptor (EGFR) signalling is critical in epithelial cancer development. Human rhomboid family-1 (RHBDF1) facilitates the secretion of TGFα, an EGFR ligand, in breast cancer; however, the underlying mechanism remains unclear. We evaluated the role for RHBDF1 in clathrin-coated vesicle (CCV)-dependent pro-TGFα membrane trafficking in breast cancer cells upon stimulation by G-protein coupled receptor (GPCR) agonists. METHODS RHBDF1 was silenced in various breast cancer cells using shRNA. TGFα levels, subcellular localization, and secretion were evaluated using ELISA, immunofluorescent staining, and coimmunoprecipitation. Phosphorylation and expression of relevant proteins were measured by western blotting. RHBDF1-dependent cell viability and invasion were measured. FINDINGS RHBDF1 mediates GPCR agonist-induced EGFR phosphorylation by promoting TGFα secretion in various types of breast cancer cells. RHBDF1 not only mediates ADAM17-dependent shedding of TGFα, but is essential in membrane trafficking of pro-TGFα. RHBDF1 silencing results in blocking of clathrin uncoating from CCV, a crucial step for the plasma membrane release of pro-TGFα. Interaction of RHBDF1 with auxilin-2, a CCV protein, determines the recruitment of HSC70 to CCV to facilitate clathrin uncoating. RHBDF1 function is required for the proliferation and mobility of breast cancer cells upon stimulation by Sphingosine 1 Phosphate (S1P), a GPCR agonist. We demonstrate a significant correlation between RHBDF1 overexpression and EGFR activation in breast cancer tissues. INTERPRETATION RHBDF1 is an indispensable component of the protein trafficking machinery involved in GPCR-mediated EGFR transactivation, and is an attractive therapeutic target for cancer. FUND: National Natural Science Foundation of China (81,672,740 to ZSZ, 81,272,356 and 81,330,029 to LYL).
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Affiliation(s)
- Jie Li
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin 300071, China.; Collaborative Innovation Center for Biotherapy and School of Medicine, Nankai University, Tianjin, 300071, China
| | - Tai-Ran Bai
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin 300071, China.; Collaborative Innovation Center for Biotherapy and School of Medicine, Nankai University, Tianjin, 300071, China
| | - Shan Gao
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin 300071, China.; Collaborative Innovation Center for Biotherapy and School of Medicine, Nankai University, Tianjin, 300071, China
| | - Zhuan Zhou
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin 300071, China
| | - Xue-Mei Peng
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin 300071, China.; Collaborative Innovation Center for Biotherapy and School of Medicine, Nankai University, Tianjin, 300071, China
| | - Li-Song Zhang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin 300071, China.; Collaborative Innovation Center for Biotherapy and School of Medicine, Nankai University, Tianjin, 300071, China
| | - Dao-Lei Dou
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin 300071, China.; Collaborative Innovation Center for Biotherapy and School of Medicine, Nankai University, Tianjin, 300071, China
| | - Zhi-Song Zhang
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin 300071, China.; Collaborative Innovation Center for Biotherapy and School of Medicine, Nankai University, Tianjin, 300071, China.
| | - Lu-Yuan Li
- State Key Laboratory of Medicinal Chemical Biology, College of Pharmacy, Tianjin Key Laboratory of Molecular Drug Research, Nankai University, Tianjin 300071, China.; Collaborative Innovation Center for Biotherapy and School of Medicine, Nankai University, Tianjin, 300071, China.
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17
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The Rhomboid Superfamily: Structural Mechanisms and Chemical Biology Opportunities. Trends Biochem Sci 2018; 43:726-739. [DOI: 10.1016/j.tibs.2018.06.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2018] [Revised: 06/08/2018] [Accepted: 06/30/2018] [Indexed: 12/27/2022]
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18
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Paschkowsky S, Recinto SJ, Young JC, Bondar AN, Munter LM. Membrane cholesterol as regulator of human rhomboid protease RHBDL4. J Biol Chem 2018; 293:15556-15568. [PMID: 30143535 DOI: 10.1074/jbc.ra118.002640] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2018] [Revised: 08/18/2018] [Indexed: 12/28/2022] Open
Abstract
In the last decade, intramembrane proteases have gained increasing attention because of their many links to various diseases. Nevertheless, our understanding as to how they function or how they are regulated is still limited, especially when it comes to human homologues. In this regard, here we sought to unravel mechanisms of regulation of the protease rhomboid-like protein-4 (RHBDL4), one of five active human serine intramembrane proteases. In view of our recent finding that human RHBDL4 efficiently cleaves the amyloid precursor protein (APP), a key protein in the pathology of Alzheimer's disease, we used established reagents to modulate the cellular cholesterol content and analyzed the effects of this modulation on RHBDL4-mediated processing of endogenous APP. We discovered that lowering membrane cholesterol levels increased the levels of RHBDL4-specific endogenous APP fragments, whereas high cholesterol levels had the opposite effect. Direct binding of cholesterol to APP did not mediate these modulating effects of cholesterol. Instead, using homology modeling, we identified two potential cholesterol-binding motifs in the transmembrane helices 3 and 6 of RHBDL4. Substitution of the essential tyrosine residues of the potential cholesterol-binding motifs to alanine increased the levels of endogenous APP C-terminal fragments, reflecting enhanced RHBDL4 activity. In summary, we provide evidence that the activity of RHBDL4 is regulated by cholesterol likely through a direct binding of cholesterol to the enzyme.
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Affiliation(s)
- Sandra Paschkowsky
- From the Department of Pharmacology and Therapeutics and Cell Information Systems Group and
| | | | - Jason C Young
- Department of Biochemistry and Groupe de Recherche Axé sur la Structure des Protéines, McGill University, Montreal, Quebec H3G 0B1, Canada and
| | - Ana-Nicoleta Bondar
- the Department of Physics, Theoretical Molecular Biophysics, Freie Universität Berlin, Arnimallee 14, Berlin 14195, Germany
| | - Lisa Marie Munter
- From the Department of Pharmacology and Therapeutics and Cell Information Systems Group and
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19
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Phosphorylation of iRhom2 Controls Stimulated Proteolytic Shedding by the Metalloprotease ADAM17/TACE. Cell Rep 2018; 21:745-757. [PMID: 29045841 PMCID: PMC5656746 DOI: 10.1016/j.celrep.2017.09.074] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 07/12/2017] [Accepted: 09/22/2017] [Indexed: 12/02/2022] Open
Abstract
Cell surface metalloproteases coordinate signaling during development, tissue homeostasis, and disease. TACE (TNF-α-converting enzyme), is responsible for cleavage (“shedding”) of membrane-tethered signaling molecules, including the cytokine TNF, and activating ligands of the EGFR. The trafficking of TACE within the secretory pathway requires its binding to iRhom2, which mediates the exit of TACE from the endoplasmic reticulum. An important, but mechanistically unclear, feature of TACE biology is its ability to be stimulated rapidly on the cell surface by numerous inflammatory and growth-promoting agents. Here, we report a role for iRhom2 in TACE stimulation on the cell surface. TACE shedding stimuli trigger MAP kinase-dependent phosphorylation of iRhom2 N-terminal cytoplasmic tail. This recruits 14-3-3 proteins, enforcing the dissociation of TACE from complexes with iRhom2, promoting the cleavage of TACE substrates. Our data reveal that iRhom2 controls multiple aspects of TACE biology, including stimulated shedding on the cell surface. iRhom2 is phosphorylated in response to stimuli that activate the sheddase TACE Blocking iRhom phosphorylation represses TACE stimulated shedding Phosphorylated iRhom2 recruits 14-3-3 and dissociates from TACE, enabling shedding iRhom2 is thus a signal integrator and transducer of stimulated TACE shedding
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20
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Adrain C, Henis-Korenblit S, Domingos PM. Meeting Report - proteostasis in Ericeira. J Cell Sci 2018; 131:131/5/jcs216150. [PMID: 29496898 DOI: 10.1242/jcs.216150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
It was a sunny Ericeira, in Portugal, that received the participants of the EMBO Workshop on Proteostasis, from 17 to 21 November 2017. Most participants gave talks or presented posters concerning their most recent research results, and lively scientific discussions occurred against the backdrop of the beautiful Atlantic Ocean.Proteostasis is the portmanteau of the words protein and homeostasis, and it refers to the biological mechanisms controlling the biogenesis, folding, trafficking and degradation of proteins in cells. An imbalance in proteostasis can lead to the accumulation of misfolded proteins or excessive protein degradation, and is associated with many human diseases. A wide variety of research approaches are used to identify the mechanisms that regulate proteostasis, typically involving different model organisms (yeast, invertebrates or mammalian systems) and different methodologies (genetics, biochemistry, biophysics, structural biology, cell biology and organismal biology). Around 140 researchers in the proteostasis field met in the Hotel Vila Galé, Ericeira, Portugal for the EMBO Workshop in Proteostasis, organized by Pedro Domingos (ITQB-NOVA, Oeiras, Portugal) and Colin Adrain (IGC, Oeiras, Portugal). In this report, we attempt to review and integrate the ideas that emerged at the workshop. Owing to space restrictions, we could not cover all talks or posters and we apologize to the colleagues whose presentations could not be discussed.
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Affiliation(s)
- Colin Adrain
- Membrane Traffic Lab, Instituto Gulbenkian de Ciência (IGC), Oeiras, Portugal
| | - Sivan Henis-Korenblit
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat-Gan, Israel
| | - Pedro M Domingos
- Instituto de Tecnologia Química e Biológica (ITQB-NOVA), Oeiras, Portugal
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21
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Neal S, Jaeger PA, Duttke SH, Benner C, K Glass C, Ideker T, Hampton RY. The Dfm1 Derlin Is Required for ERAD Retrotranslocation of Integral Membrane Proteins. Mol Cell 2018; 69:306-320.e4. [PMID: 29351849 PMCID: PMC6049073 DOI: 10.1016/j.molcel.2017.12.012] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 10/06/2017] [Accepted: 11/15/2017] [Indexed: 12/13/2022]
Abstract
Endoplasmic reticulum (ER)-associated degradation (ERAD) removes misfolded proteins from the ER membrane and lumen by the ubiquitin-proteasome pathway. Retrotranslocation of ubiquitinated substrates to the cytosol is a universal feature of ERAD that requires the Cdc48 AAA-ATPase. Despite intense efforts, the mechanism of ER exit, particularly for integral membrane (ERAD-M) substrates, has remained unclear. Using a self-ubiquitinating substrate (SUS), which undergoes normal retrotranslocation independently of known ERAD factors, and the new SPOCK (single plate orf compendium kit) micro-library to query all yeast genes, we found the rhomboid derlin Dfm1 was required for retrotranslocation of both HRD and DOA ERAD pathway integral membrane substrates. Dfm1 recruited Cdc48 to the ER membrane with its unique SHP motifs, and it catalyzed substrate extraction through its conserved rhomboid motifs. Surprisingly, dfm1Δ can undergo rapid suppression, restoring wild-type ERAD-M. This unexpected suppression explained earlier studies ruling out Dfm1, and it revealed an ancillary ERAD-M retrotranslocation pathway requiring Hrd1.
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Affiliation(s)
- Sonya Neal
- Division of Biological Sciences, the Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Philipp A Jaeger
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Biocipher(X), Inc., San Diego, CA 92121, USA
| | - Sascha H Duttke
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Christopher Benner
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Christopher K Glass
- Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Trey Ideker
- Department of Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
| | - Randolph Y Hampton
- Division of Biological Sciences, the Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA 92093, USA.
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22
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Cavalier-Smith T. Kingdom Chromista and its eight phyla: a new synthesis emphasising periplastid protein targeting, cytoskeletal and periplastid evolution, and ancient divergences. PROTOPLASMA 2018; 255:297-357. [PMID: 28875267 PMCID: PMC5756292 DOI: 10.1007/s00709-017-1147-3] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 07/18/2017] [Indexed: 05/18/2023]
Abstract
In 1981 I established kingdom Chromista, distinguished from Plantae because of its more complex chloroplast-associated membrane topology and rigid tubular multipartite ciliary hairs. Plantae originated by converting a cyanobacterium to chloroplasts with Toc/Tic translocons; most evolved cell walls early, thereby losing phagotrophy. Chromists originated by enslaving a phagocytosed red alga, surrounding plastids by two extra membranes, placing them within the endomembrane system, necessitating novel protein import machineries. Early chromists retained phagotrophy, remaining naked and repeatedly reverted to heterotrophy by losing chloroplasts. Therefore, Chromista include secondary phagoheterotrophs (notably ciliates, many dinoflagellates, Opalozoa, Rhizaria, heliozoans) or walled osmotrophs (Pseudofungi, Labyrinthulea), formerly considered protozoa or fungi respectively, plus endoparasites (e.g. Sporozoa) and all chromophyte algae (other dinoflagellates, chromeroids, ochrophytes, haptophytes, cryptophytes). I discuss their origin, evolutionary diversification, and reasons for making chromists one kingdom despite highly divergent cytoskeletons and trophic modes, including improved explanations for periplastid/chloroplast protein targeting, derlin evolution, and ciliary/cytoskeletal diversification. I conjecture that transit-peptide-receptor-mediated 'endocytosis' from periplastid membranes generates periplastid vesicles that fuse with the arguably derlin-translocon-containing periplastid reticulum (putative red algal trans-Golgi network homologue; present in all chromophytes except dinoflagellates). I explain chromist origin from ancestral corticates and neokaryotes, reappraising tertiary symbiogenesis; a chromist cytoskeletal synapomorphy, a bypassing microtubule band dextral to both centrioles, favoured multiple axopodial origins. I revise chromist higher classification by transferring rhizarian subphylum Endomyxa from Cercozoa to Retaria; establishing retarian subphylum Ectoreta for Foraminifera plus Radiozoa, apicomonad subclasses, new dinozoan classes Myzodinea (grouping Colpovora gen. n., Psammosa), Endodinea, Sulcodinea, and subclass Karlodinia; and ranking heterokont Gyrista as phylum not superphylum.
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23
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Düsterhöft S, Künzel U, Freeman M. Rhomboid proteases in human disease: Mechanisms and future prospects. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2017; 1864:2200-2209. [PMID: 28460881 DOI: 10.1016/j.bbamcr.2017.04.016] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 04/24/2017] [Accepted: 04/26/2017] [Indexed: 01/19/2023]
Abstract
Rhomboids are intramembrane serine proteases that cleave the transmembrane helices of substrate proteins, typically releasing luminal/extracellular domains from the membrane. They are conserved in all branches of life and there is a growing recognition of their association with a wide range of human diseases. Human rhomboids, for example, have been implicated in cancer, metabolic disease and neurodegeneration, while rhomboids in apicomplexan parasites appear to contribute to their invasion of host cells. Recent advances in our knowledge of the structure and the enzyme function of rhomboids, and increasing efforts to identify specific inhibitors, are beginning to provide important insight into the prospect of rhomboids becoming future therapeutic targets. This article is part of a Special Issue entitled: Proteolysis as a Regulatory Event in Pathophysiology edited by Stefan Rose-John.
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Affiliation(s)
- Stefan Düsterhöft
- Dunn School of Pathology, University of Oxford, OX1 3RE, United Kingdom
| | - Ulrike Künzel
- Dunn School of Pathology, University of Oxford, OX1 3RE, United Kingdom
| | - Matthew Freeman
- Dunn School of Pathology, University of Oxford, OX1 3RE, United Kingdom.
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24
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Grieve AG, Xu H, Künzel U, Bambrough P, Sieber B, Freeman M. Phosphorylation of iRhom2 at the plasma membrane controls mammalian TACE-dependent inflammatory and growth factor signalling. eLife 2017; 6. [PMID: 28432785 PMCID: PMC5436907 DOI: 10.7554/elife.23968] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 04/20/2017] [Indexed: 12/21/2022] Open
Abstract
Proteolytic cleavage and release from the cell surface of membrane-tethered ligands is an important mechanism of regulating intercellular signalling. TACE is a major shedding protease, responsible for the liberation of the inflammatory cytokine TNFα and ligands of the epidermal growth factor receptor. iRhoms, catalytically inactive members of the rhomboid-like superfamily, have been shown to control the ER-to-Golgi transport and maturation of TACE. Here, we reveal that iRhom2 remains associated with TACE throughout the secretory pathway, and is stabilised at the cell surface by this interaction. At the plasma membrane, ERK1/2-mediated phosphorylation and 14-3-3 protein binding of the cytoplasmic amino-terminus of iRhom2 alter its interaction with mature TACE, thereby licensing its proteolytic activity. We show that this molecular mechanism is responsible for triggering inflammatory responses in primary mouse macrophages. Overall, iRhom2 binds to TACE throughout its lifecycle, implying that iRhom2 is a primary regulator of stimulated cytokine and growth factor signalling. DOI:http://dx.doi.org/10.7554/eLife.23968.001 Injury or infection can cause tissues in the body to become inflamed. The immune system triggers this inflammation to help repair the injury or fight the infection. A signal molecule known as TNF – which is produced by immune cells called macrophages – triggers inflammation. This protein is normally attached to the surface of the macrophage, and it only activates inflammation once it has been cut free. An enzyme called TACE cuts and releases TNF from the surface of macrophages. This enzyme is made inside the cell and is then transported to the surface. On the way, TACE matures from an inactive form to a fully functional enzyme. Previous work revealed that a protein called iRhom2 controls TACE maturation, but it has been unclear whether iRhom2 affects TACE in any additional ways. Grieve et al. studied the relationship between iRhom2 and TACE in more detail. The experiments show two new roles for iRhom2: in protecting TACE from being destroyed at the cell surface, and prompting TACE to release TNF to trigger inflammation. Injury or infection causes small molecules called phosphate groups to be attached to iRhom2 in macrophages, which causes TACE to release TNF. The findings of Grieve et al. provide the first evidence that iRhom2 influences the activity of TACE throughout the enzyme’s lifetime. Excessive inflammation, often triggered by the uncontrolled release of TNF, can lead to rheumatoid arthritis, cancer and many other diseases. Therefore, iRhom2 could be a promising new target for anti-inflammatory drugs that may help to treat these conditions. DOI:http://dx.doi.org/10.7554/eLife.23968.002
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Affiliation(s)
- Adam Graham Grieve
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Hongmei Xu
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Ulrike Künzel
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Paul Bambrough
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Boris Sieber
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
| | - Matthew Freeman
- Sir William Dunn School of Pathology, University of Oxford, Oxford, United Kingdom
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25
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Urban S. A guide to the rhomboid protein superfamily in development and disease. Semin Cell Dev Biol 2016; 60:1-4. [PMID: 27751777 DOI: 10.1016/j.semcdb.2016.10.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 10/13/2016] [Indexed: 11/28/2022]
Abstract
Rhomboid proteins are considered to be the most widespread membrane proteins across all forms of life. This superfamily comprises both active intramembrane serine proteases that catalyze the release of factors from the membrane, and a eukaryotic subset of non-catalytic members in which rhomboid architecture supports deviating functions. Although rhomboid was discovered in genetic studies of insect development, rhomboid research has broadened dramatically over the past 15 years; rhomboid enzymes are now the best biophysically understood of all intramembrane proteases, and are considered promising therapeutic targets for diseases ranging from parasitic infections to Parkinsonian neurodegeneration. Perhaps the most rapid progress has come with the catalytically inert rhomboid proteins, some of which regulate protein trafficking and/or function, and their prominence is underscored by clinical mutations. Such a diverse collection of advances mark an excellent point to review the state of this vibrant area of research, not because central questions have been answered, but instead because a firm grip in key areas has been established, and the field is now poised for breakthroughs.
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Affiliation(s)
- Siniša Urban
- Department of Molecular Biology & Genetics, Johns Hopkins University School of Medicine, Room 507 PCTB, 725 North Wolfe Street, Baltimore, MD, 21205, USA.
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