1
|
Voss M. Proteolytic cleavage of Golgi glycosyltransferases by SPPL3 and other proteases and its implications for cellular glycosylation. Biochim Biophys Acta Gen Subj 2024; 1868:130668. [PMID: 38992482 DOI: 10.1016/j.bbagen.2024.130668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2024] [Revised: 07/03/2024] [Accepted: 07/05/2024] [Indexed: 07/13/2024]
Abstract
Glycosylation of proteins and lipids is of fundamental importance in multicellular eukaryotes. The vast diversity of glycan structures observed is generated in the Golgi apparatus by the concerted activity of >100 distinct enzymes, which include glycosyltransferases and other glycan-modifying enzymes. Well-known for decades, the majority of these enzymes is released from the Golgi apparatus and subsequently secreted into the extracellular space following endoproteolytic cleavage, but the underlying molecular mechanisms and the physiological implications have remained unexplored. This review will summarize our current knowledge of Golgi enzyme proteolysis and secretion and will discuss its conceptual implications for the regulation of cellular glycosylation and the organization of the Golgi apparatus. A particular focus will lie on the intramembrane protease SPPL3, which recently emerged as key protease facilitating Golgi enzyme release and has since been shown to affect a multitude of glycosylation-dependent physiological processes.
Collapse
Affiliation(s)
- Matthias Voss
- Institute of Biochemistry, Kiel University, Kiel, Germany.
| |
Collapse
|
2
|
Ng BG, Freeze HH, Himmelreich N, Blau N, Ferreira CR. Clinical and biochemical footprints of congenital disorders of glycosylation: Proposed nosology. Mol Genet Metab 2024; 142:108476. [PMID: 38653092 PMCID: PMC11251693 DOI: 10.1016/j.ymgme.2024.108476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Revised: 04/08/2024] [Accepted: 04/09/2024] [Indexed: 04/25/2024]
Abstract
We have identified 200 congenital disorders of glycosylation (CDG) caused by 189 different gene defects and have proposed a classification system for CDG based on the mode of action. This classification includes 8 categories: 1. Disorders of monosaccharide synthesis and interconversion, 2. Disorders of nucleotide sugar synthesis and transport, 3. Disorders of N-linked protein glycosylation, 4. Disorders of O-linked protein glycosylation, 5. Disorders of lipid glycosylation, 6. Disorders of vesicular trafficking, 7. Disorders of multiple glycosylation pathways and 8. Disorders of glycoprotein/glycan degradation. Additionally, using information from IEMbase, we have described the clinical involvement of 19 organs and systems, as well as essential laboratory investigations for each type of CDG. Neurological, dysmorphic, skeletal, and ocular manifestations were the most prevalent, occurring in 81%, 56%, 53%, and 46% of CDG, respectively. This was followed by digestive, cardiovascular, dermatological, endocrine, and hematological symptoms (17-34%). Immunological, genitourinary, respiratory, psychiatric, and renal symptoms were less frequently reported (8-12%), with hair and dental abnormalities present in only 4-7% of CDG. The information provided in this study, including our proposed classification system for CDG, may be beneficial for healthcare providers caring for individuals with metabolic conditions associated with CDG.
Collapse
Affiliation(s)
- Bobby G Ng
- Human Genetics Program, Sanford Children's Health Research Center, La Jolla, CA, USA
| | - Hudson H Freeze
- Human Genetics Program, Sanford Children's Health Research Center, La Jolla, CA, USA.
| | - Nastassja Himmelreich
- Dietmar-Hopp Metabolic Center and Centre for Pediatrics and Adolescent Medicine, University Children's Hospital, Heidelberg, Germany; Center for Human Genetics Tübingen, Tübingen, Germany
| | - Nenad Blau
- Divisions of Metabolism, University Children's Hospital, Zürich, Switzerland.
| | - Carlos R Ferreira
- National Human Genome Research Institute, National Institutes of Health, Bethesda, MD, USA.
| |
Collapse
|
3
|
Ghasemi MR, Tehrani Fateh S, Moeinafshar A, Sadeghi H, Karimzadeh P, Mirfakhraie R, Rezaei M, Hashemi-Gorji F, Rezvani Kashani M, Fazeli Bavandpour F, Bagheri S, Moghimi P, Rostami M, Madannejad R, Roudgari H, Miryounesi M. Broadening the phenotype and genotype spectrum of novel mutations in pontocerebellar hypoplasia with a comprehensive molecular literature review. BMC Med Genomics 2024; 17:51. [PMID: 38347586 PMCID: PMC10863249 DOI: 10.1186/s12920-024-01810-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 01/16/2024] [Indexed: 02/15/2024] Open
Abstract
BACKGROUND Pontocerebellar hypoplasia is an umbrella term describing a heterogeneous group of prenatal neurodegenerative disorders mostly affecting the pons and cerebellum, with 17 types associated with 25 genes. However, some types of PCH lack sufficient information, which highlights the importance of investigating and introducing more cases to further elucidate the clinical, radiological, and biochemical features of these disorders. The aim of this study is to provide an in-depth review of PCH and to identify disease genes and their inheritance patterns in 12 distinct Iranian families with clinically confirmed PCH. METHODS Cases included in this study were selected based on their phenotypic and genetic information available at the Center for Comprehensive Genetic Services. Whole-exome sequencing (WES) was used to discover the underlying genetic etiology of participants' problems, and Sanger sequencing was utilized to confirm any suspected alterations. We also conducted a comprehensive molecular literature review to outline the genetic features of the various subtypes of PCH. RESULTS This study classified and described the underlying etiology of PCH into three categories based on the genes involved. Twelve patients also were included, eleven of whom were from consanguineous parents. Ten different variations in 8 genes were found, all of which related to different types of PCH. Six novel variations were reported, including SEPSECS, TSEN2, TSEN54, AMPD2, TOE1, and CLP1. Almost all patients presented with developmental delay, hypotonia, seizure, and microcephaly being common features. Strabismus and elevation in lactate levels in MR spectroscopy were novel phenotypes for the first time in PCH types 7 and 9. CONCLUSIONS This study merges previously documented phenotypes and genotypes with unique novel ones. Due to the diversity in PCH, we provided guidance for detecting and diagnosing these heterogeneous groups of disorders. Moreover, since certain critical conditions, such as spinal muscular atrophy, can be a differential diagnosis, providing cases with novel variations and clinical findings could further expand the genetic and clinical spectrum of these diseases and help in better diagnosis. Therefore, six novel genetic variants and novel clinical and paraclinical findings have been reported for the first time. Further studies are needed to elucidate the underlying mechanisms and potential therapeutic targets for PCH.
Collapse
Affiliation(s)
- Mohammad-Reza Ghasemi
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, , Tehran, Iran
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Aysan Moeinafshar
- School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | - Hossein Sadeghi
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, , Tehran, Iran
| | - Parvaneh Karimzadeh
- Pediatric Neurology Department, Mofid Children's Hospital, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Reza Mirfakhraie
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, , Tehran, Iran
| | - Mitra Rezaei
- Genomic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Farzad Hashemi-Gorji
- Genomic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Morteza Rezvani Kashani
- Pediatric Neurology Department, Mofid Children's Hospital, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Saman Bagheri
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- School of Medicine, Islamic Azad University Tehran Medical Sciences, Tehran, Iran
| | - Parinaz Moghimi
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- School of Medicine, Islamic Azad University Tehran Medical Sciences, Tehran, Iran
| | - Masoumeh Rostami
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Rasoul Madannejad
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hassan Roudgari
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
- Genomic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Miryounesi
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, , Tehran, Iran.
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Genomic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
4
|
D'Souza Z, Pokrovskaya I, Lupashin VV. Syntaxin-5's flexibility in SNARE pairing supports Golgi functions. Traffic 2023; 24:355-379. [PMID: 37340984 PMCID: PMC10330844 DOI: 10.1111/tra.12903] [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: 03/07/2023] [Revised: 05/23/2023] [Accepted: 06/02/2023] [Indexed: 06/22/2023]
Abstract
Deficiency in the conserved oligomeric Golgi (COG) complex that orchestrates SNARE-mediated tethering/fusion of vesicles that recycle the Golgi's glycosylation machinery results in severe glycosylation defects. Although two major Golgi v-SNAREs, GS28/GOSR1, and GS15/BET1L, are depleted in COG-deficient cells, the complete knockout of GS28 and GS15 only modestly affects Golgi glycosylation, indicating the existence of an adaptation mechanism in Golgi SNARE. Indeed, quantitative mass-spectrometry analysis of STX5-interacting proteins revealed two novel Golgi SNARE complexes-STX5/SNAP29/VAMP7 and STX5/VTI1B/STX8/YKT6. These complexes are present in wild-type cells, but their usage is significantly increased in both GS28- and COG-deficient cells. Upon GS28 deletion, SNAP29 increased its Golgi residency in a STX5-dependent manner. While STX5 depletion and Retro2-induced diversion from the Golgi severely affect protein glycosylation, GS28/SNAP29 and GS28/VTI1B double knockouts alter glycosylation similarly to GS28 KO, indicating that a single STX5-based SNARE complex is sufficient to support Golgi glycosylation. Importantly, co-depletion of three Golgi SNARE complexes in GS28/SNAP29/VTI1B TKO cells resulted in severe glycosylation defects and a reduced capacity for glycosylation enzyme retention at the Golgi. This study demonstrates the remarkable plasticity in SXT5-mediated membrane trafficking, uncovering a novel adaptive response to the failure of canonical intra-Golgi vesicle tethering/fusion machinery.
Collapse
Affiliation(s)
- Zinia D'Souza
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Irina Pokrovskaya
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Vladimir V Lupashin
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| |
Collapse
|
5
|
Puzio M, Moreton N, Sullivan M, Scaife C, Glennon JC, O'Connor JJ. An Electrophysiological and Proteomic Analysis of the Effects of the Superoxide Dismutase Mimetic, MnTMPyP, on Synaptic Signalling Post-Ischemia in Isolated Rat Hippocampal Slices. Antioxidants (Basel) 2023; 12:antiox12040792. [PMID: 37107167 PMCID: PMC10135248 DOI: 10.3390/antiox12040792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/17/2023] [Accepted: 03/21/2023] [Indexed: 04/29/2023] Open
Abstract
Metabolic stress and the increased production of reactive oxygen species (ROS) are two main contributors to neuronal damage and synaptic plasticity in acute ischemic stroke. The superoxide scavenger MnTMPyP has been previously reported to have a neuroprotective effect in organotypic hippocampal slices and to modulate synaptic transmission after in vitro hypoxia and oxygen-glucose deprivation (OGD). However, the mechanisms involved in the effect of this scavenger remain elusive. In this study, two concentrations of MnTMPyP were evaluated on synaptic transmission during ischemia and post-ischemic synaptic potentiation. The complex molecular changes supporting cellular adaptation to metabolic stress, and how these are modulated by MnTMPyP, were also investigated. Electrophysiological data showed that MnTMPyP causes a decrease in baseline synaptic transmission and impairment of synaptic potentiation. Proteomic analysis performed on MnTMPyP and hypoxia-treated tissue indicated an impairment in vesicular trafficking mechanisms, including reduced expression of Hsp90 and actin signalling. Alterations of vesicular trafficking may lead to reduced probability of neurotransmitter release and AMPA receptor activity, resulting in the observed modulatory effect of MnTMPyP. In OGD, protein enrichment analysis highlighted impairments in cell proliferation and differentiation, such as TGFβ1 and CDKN1B signalling, in addition to downregulation of mitochondrial dysfunction and an increased expression of CAMKII. Taken together, our results may indicate modulation of neuronal sensitivity to the ischemic insult, and a complex role for MnTMPyP in synaptic transmission and plasticity, potentially providing molecular insights into the mechanisms mediating the effects of MnTMPyP during ischemia.
Collapse
Affiliation(s)
- Martina Puzio
- UCD School of Biomolecular & Biomedical Science, University College Dublin, Dublin 4, Ireland
- Mass Spectrometry Core Facility, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Niamh Moreton
- UCD School of Biomolecular & Biomedical Science, University College Dublin, Dublin 4, Ireland
- Mass Spectrometry Core Facility, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Mairéad Sullivan
- Mass Spectrometry Core Facility, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin 4, Ireland
- UCD School of Medicine, University College Dublin, Dublin 4, Ireland
| | - Caitriona Scaife
- Mass Spectrometry Core Facility, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Jeffrey C Glennon
- Mass Spectrometry Core Facility, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin 4, Ireland
- UCD School of Medicine, University College Dublin, Dublin 4, Ireland
| | - John J O'Connor
- UCD School of Biomolecular & Biomedical Science, University College Dublin, Dublin 4, Ireland
- Mass Spectrometry Core Facility, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin 4, Ireland
| |
Collapse
|
6
|
Khakurel A, Lupashin VV. Role of GARP Vesicle Tethering Complex in Golgi Physiology. Int J Mol Sci 2023; 24:6069. [PMID: 37047041 PMCID: PMC10094427 DOI: 10.3390/ijms24076069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/17/2023] [Accepted: 03/19/2023] [Indexed: 04/14/2023] Open
Abstract
The Golgi associated retrograde protein complex (GARP) is an evolutionarily conserved component of Golgi membrane trafficking machinery that belongs to the Complexes Associated with Tethering Containing Helical Rods (CATCHR) family. Like other multisubunit tethering complexes such as COG, Dsl1, and Exocyst, the GARP is believed to function by tethering and promoting fusion of the endosome-derived small trafficking intermediate. However, even twenty years after its discovery, the exact structure and the functions of GARP are still an enigma. Recent studies revealed novel roles for GARP in Golgi physiology and identified human patients with mutations in GARP subunits. In this review, we summarized our knowledge of the structure of the GARP complex, its protein partners, GARP functions related to Golgi physiology, as well as cellular defects associated with the dysfunction of GARP subunits.
Collapse
Affiliation(s)
| | - Vladimir V. Lupashin
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| |
Collapse
|
7
|
Khakurel A, Kudlyk T, Lupashin VV. Generation and Analysis of hTERT-RPE1 VPS54 Knock-Out and Rescued Cell Lines. Methods Mol Biol 2023; 2557:349-364. [PMID: 36512226 PMCID: PMC10026839 DOI: 10.1007/978-1-0716-2639-9_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The Golgi-associated retrograde protein (GARP) complex is proposed to tether endosome-derived transport vesicles, but the exact function and mechanism of GARP action are not completely understood. To uncover the GARP function in human cells, we employ CRISPR/Cas9 strategy and knock out (KO) the unique VPS54 subunit of the GARP complex. In this chapter, we describe the detailed method of generating CRISPR/Cas9-mediated VPS54-KO in hTERT-RPE1 cells, rescue of resulting KO cells with stable near-endogenous expression of myc-tagged VPS54, and validation of KO and rescued (KO-R) cells using Western blot and immunofluorescence approaches. This approach is helpful in uncovering new functions of the GARP and other vesicle tethering complexes.
Collapse
Affiliation(s)
- Amrita Khakurel
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Tetyana Kudlyk
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Vladimir V Lupashin
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| |
Collapse
|
8
|
De Tito S, Turacchio G, Valente C. Negative Staining Electron Microscopy for Morpho-Functional Characterization of Purified Golgi Membranes from Mammalian Cells. Methods Mol Biol 2022; 2557:225-234. [PMID: 36512218 DOI: 10.1007/978-1-0716-2639-9_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The Golgi apparatus is a highly dynamic organelle that controls lipid and protein sorting in the endocytic and exocytic cellular pathways. Perturbation of the lipid homeostasis or of the molecular machineries that regulate membrane remodeling/trafficking events on the Golgi membranes can dramatically change the morphology and functions of the Golgi apparatus. So far, several approaches have been described to characterize and define the Golgi morphology in intact cells and in vitro. Here, we describe the application of negative staining (NS) electron microscopy (EM) on purified Golgi membranes from HeLa cells. This approach allows to quantify and functionally characterize membrane remodeling events upon specific treatments that alter the Golgi morphology.
Collapse
Affiliation(s)
- Stefano De Tito
- Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy.,Molecular Cell Biology of Autophagy, The Francis Crick Institute, London, UK
| | - Gabriele Turacchio
- Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy
| | - Carmen Valente
- Institute of Experimental Endocrinology and Oncology, National Research Council, Naples, Italy.
| |
Collapse
|
9
|
Khakurel A, Kudlyk T, Pokrovskaya I, D’Souza Z, Lupashin VV. GARP dysfunction results in COPI displacement, depletion of Golgi v-SNAREs and calcium homeostasis proteins. Front Cell Dev Biol 2022; 10:1066504. [PMID: 36578782 PMCID: PMC9791199 DOI: 10.3389/fcell.2022.1066504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 11/30/2022] [Indexed: 12/14/2022] Open
Abstract
Golgi-associated retrograde protein (GARP) is an evolutionary conserved heterotetrameric protein complex that tethers endosome-derived vesicles and is vital for Golgi glycosylation. Microscopy and proteomic approaches were employed to investigate defects in Golgi physiology in RPE1 cells depleted for the GARP complex. Both cis and trans-Golgi compartments were significantly enlarged in GARP-knock-out (KO) cells. Proteomic analysis of Golgi-enriched membranes revealed significant depletion of a subset of Golgi residents, including Ca2+ binding proteins, enzymes, and SNAREs. Validation of proteomics studies revealed that SDF4 and ATP2C1, related to Golgi calcium homeostasis, as well as intra-Golgi v-SNAREs GOSR1 and BET1L, were significantly depleted in GARP-KO cells. Finding that GARP-KO is more deleterious to Golgi physiology than deletion of GARP-sensitive v-SNAREs, prompted a detailed investigation of COPI trafficking machinery. We discovered that in GARP-KO cells COPI is significantly displaced from the Golgi and partially relocalized to the ER-Golgi intermediate compartment (ERGIC). Moreover, COPI accessory proteins GOLPH3, ARFGAP1, GBF1, and BIG1 are also relocated to off-Golgi compartments. We propose that the dysregulation of COPI machinery, along with the depletion of Golgi v-SNAREs and alteration of Golgi Ca2+ homeostasis, are the major driving factors for the depletion of Golgi resident proteins, structural alterations, and glycosylation defects in GARP deficient cells.
Collapse
Affiliation(s)
| | | | | | | | - Vladimir V. Lupashin
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| |
Collapse
|
10
|
Truberg J, Hobohm L, Jochimsen A, Desel C, Schweizer M, Voss M. Endogenous tagging reveals a mid-Golgi localization of the glycosyltransferase-cleaving intramembrane protease SPPL3. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2022; 1869:119345. [PMID: 36007678 DOI: 10.1016/j.bbamcr.2022.119345] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 08/16/2022] [Accepted: 08/16/2022] [Indexed: 06/15/2023]
Abstract
Numerous Golgi-resident enzymes implicated in glycosylation are regulated by the conserved intramembrane protease SPPL3. SPPL3-catalyzed endoproteolysis separates Golgi enzymes from their membrane anchors, enabling subsequent release from the Golgi and secretion. Experimentally altered SPPL3 expression changes glycosylation patterns, yet the regulation of SPPL3-mediated Golgi enzyme cleavage is not understood and conflicting results regarding the subcellular localization of SPPL3 have been reported. Here, we used precise genome editing to generate isogenic cell lines expressing N- or C-terminally tagged SPPL3 from its endogenous locus. Using these cells, we conducted co-localization analyses of tagged endogenous SPPL3 and Golgi markers under steady-state conditions and upon treatment with drugs disrupting Golgi organization. Our data demonstrate that endogenous SPPL3 is Golgi-resident and found predominantly in the mid-Golgi. We find that endogenous SPPL3 co-localizes with its substrates but similarly with non-substrate type II proteins, demonstrating that in addition to co-localization in the Golgi other substrate-intrinsic properties govern SPPL3-mediated intramembrane proteolysis. Given the prevalence of SPPL3-mediated cleavage among Golgi-resident proteins our results have important implications for the regulation of SPPL3 and its role in the organization of the Golgi glycosylation machinery.
Collapse
Affiliation(s)
- Jule Truberg
- Institute of Biochemistry, Kiel University, Rudolf-Höber-Str. 1, D-24118 Kiel, Germany
| | - Laura Hobohm
- Institute of Biochemistry, Kiel University, Rudolf-Höber-Str. 1, D-24118 Kiel, Germany
| | - Alexander Jochimsen
- Institute of Biochemistry, Kiel University, Rudolf-Höber-Str. 1, D-24118 Kiel, Germany
| | - Christine Desel
- Institute of Biochemistry, Kiel University, Rudolf-Höber-Str. 1, D-24118 Kiel, Germany
| | - Michaela Schweizer
- Morphology and Electron Microscopy, University Medical Center Hamburg-Eppendorf, Center for Molecular Neurobiology (ZMNH), 20251 Hamburg, Germany
| | - Matthias Voss
- Institute of Biochemistry, Kiel University, Rudolf-Höber-Str. 1, D-24118 Kiel, Germany.
| |
Collapse
|
11
|
Spano D, Colanzi A. Golgi Complex: A Signaling Hub in Cancer. Cells 2022; 11:1990. [PMID: 35805075 PMCID: PMC9265605 DOI: 10.3390/cells11131990] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/17/2022] [Accepted: 06/19/2022] [Indexed: 02/01/2023] Open
Abstract
The Golgi Complex is the central hub in the endomembrane system and serves not only as a biosynthetic and processing center but also as a trafficking and sorting station for glycoproteins and lipids. In addition, it is an active signaling hub involved in the regulation of multiple cellular processes, including cell polarity, motility, growth, autophagy, apoptosis, inflammation, DNA repair and stress responses. As such, the dysregulation of the Golgi Complex-centered signaling cascades contributes to the onset of several pathological conditions, including cancer. This review summarizes the current knowledge on the signaling pathways regulated by the Golgi Complex and implicated in promoting cancer hallmarks and tumor progression.
Collapse
Affiliation(s)
- Daniela Spano
- Institute of Biochemistry and Cell Biology, National Research Council, Via Pietro Castellino 111, 80131 Naples, Italy
| | - Antonino Colanzi
- Institute for Endocrinology and Experimental Oncology “G. Salvatore”, National Research Council, 80131 Naples, Italy;
| |
Collapse
|
12
|
Sardana R, Highland CM, Straight BE, Chavez CF, Fromme JC, Emr SD. Golgi membrane protein Erd1 Is essential for recycling a subset of Golgi glycosyltransferases. eLife 2021; 10:e70774. [PMID: 34821548 PMCID: PMC8616560 DOI: 10.7554/elife.70774] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 11/17/2021] [Indexed: 12/24/2022] Open
Abstract
Protein glycosylation in the Golgi is a sequential process that requires proper distribution of transmembrane glycosyltransferase enzymes in the appropriate Golgi compartments. Some of the cytosolic machinery required for the steady-state localization of some Golgi enzymes are known but existing models do not explain how many of these enzymes are localized. Here, we uncover the role of an integral membrane protein in yeast, Erd1, as a key facilitator of Golgi glycosyltransferase recycling by directly interacting with both the Golgi enzymes and the cytosolic receptor, Vps74. Loss of Erd1 function results in mislocalization of Golgi enzymes to the vacuole/lysosome. We present evidence that Erd1 forms an integral part of the recycling machinery and ensures productive recycling of several early Golgi enzymes. Our work provides new insights on how the localization of Golgi glycosyltransferases is spatially and temporally regulated, and is finely tuned to the cues of Golgi maturation.
Collapse
Affiliation(s)
- Richa Sardana
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
- Department of Molecular Medicine, Cornell UniversityIthacaUnited States
| | - Carolyn M Highland
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
| | - Beth E Straight
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
| | - Christopher F Chavez
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
| | - J Christopher Fromme
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
| | - Scott D Emr
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
| |
Collapse
|
13
|
D’Souza Z, Sumya FT, Khakurel A, Lupashin V. Getting Sugar Coating Right! The Role of the Golgi Trafficking Machinery in Glycosylation. Cells 2021; 10:cells10123275. [PMID: 34943782 PMCID: PMC8699264 DOI: 10.3390/cells10123275] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 11/17/2021] [Accepted: 11/19/2021] [Indexed: 12/18/2022] Open
Abstract
The Golgi is the central organelle of the secretory pathway and it houses the majority of the glycosylation machinery, which includes glycosylation enzymes and sugar transporters. Correct compartmentalization of the glycosylation machinery is achieved by retrograde vesicular trafficking as the secretory cargo moves forward by cisternal maturation. The vesicular trafficking machinery which includes vesicular coats, small GTPases, tethers and SNAREs, play a major role in coordinating the Golgi trafficking thereby achieving Golgi homeostasis. Glycosylation is a template-independent process, so its fidelity heavily relies on appropriate localization of the glycosylation machinery and Golgi homeostasis. Mutations in the glycosylation enzymes, sugar transporters, Golgi ion channels and several vesicle tethering factors cause congenital disorders of glycosylation (CDG) which encompass a group of multisystem disorders with varying severities. Here, we focus on the Golgi vesicle tethering and fusion machinery, namely, multisubunit tethering complexes and SNAREs and their role in Golgi trafficking and glycosylation. This review is a comprehensive summary of all the identified CDG causing mutations of the Golgi trafficking machinery in humans.
Collapse
|
14
|
Sumya FT, Pokrovskaya ID, Lupashin V. Development and Initial Characterization of Cellular Models for COG Complex-Related CDG-II Diseases. Front Genet 2021; 12:733048. [PMID: 34603392 PMCID: PMC8484713 DOI: 10.3389/fgene.2021.733048] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 09/06/2021] [Indexed: 12/12/2022] Open
Abstract
Conserved Oligomeric Golgi (COG) is an octameric protein complex that orchestrates intra-Golgi trafficking of glycosylation enzymes. Over a hundred individuals with 31 different COG mutations have been identified until now. The cellular phenotypes and clinical presentations of COG-CDGs are heterogeneous, and patients primarily represent neurological, skeletal, and hepatic abnormalities. The establishment of a cellular COG disease model will benefit the molecular study of the disease, explaining the detailed sequence of the interplay between the COG complex and the trafficking machinery. Moreover, patient fibroblasts are not a good representative of all the organ systems and cell types that are affected by COG mutations. We developed and characterized cellular models for human COG4 mutations, specifically in RPE1 and HEK293T cell lines. Using a combination of CRISPR/Cas9 and lentiviral transduction technologies, both myc-tagged wild-type and mutant (G516R and R729W) COG4 proteins were expressed under the endogenous COG4 promoter. Constructed isogenic cell lines were comprehensively characterized using biochemical, microscopy (superresolution and electron), and proteomics approaches. The analysis revealed similar stability and localization of COG complex subunits, wild-type cell growth, and normal Golgi morphology in all three cell lines. Importantly, COG4-G516R cells demonstrated increased HPA-647 binding to the plasma membrane glycoconjugates, while COG4-R729W cells revealed high GNL-647 binding, indicating specific defects in O- and N-glycosylation. Both mutant cell lines express an elevated level of heparin sulfate proteoglycans. Moreover, a quantitative mass-spectrometry analysis of proteins secreted by COG-deficient cell lines revealed abnormal secretion of SIL1 and ERGIC-53 proteins by COG4-G516R cells. Interestingly, the clinical phenotype of patients with congenital mutations in the SIL1 gene (Marinesco-Sjogren syndrome) overlaps with the phenotype of COG4-G516R patients (Saul-Wilson syndrome). Our work is the first compressive study involving the creation of different COG mutations in different cell lines other than the patient's fibroblast. It may help to address the underlying cause of the phenotypic defects leading to the discovery of a proper treatment guideline for COG-CDGs.
Collapse
Affiliation(s)
| | | | - Vladimir Lupashin
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, AR, United States
| |
Collapse
|