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Abstract
The mammalian Golgi apparatus is a highly dynamic organelle, which is normally localized in the juxtanuclear space and plays an essential role in the regulation of cellular homeostasis. While posttranslational modification of cargo is mediated by the resident enzymes (glycosyltransferases, glycosidases, and kinases), the ribbon structure of Golgi and its cisternal stacking mostly rely on the cooperation of coiled-coil matrix golgins. Among them, giantin, GM130, and GRASPs are unique, because they form a tripartite complex and serve as Golgi docking sites for cargo delivered from the endoplasmic reticulum (ER). Golgi undergoes significant disorganization in many pathologies associated with a block of the ER-to-Golgi or intra-Golgi transport, including cancer, different neurological diseases, alcoholic liver damage, ischemic stress, viral infections, etc. In addition, Golgi fragments during apoptosis and mitosis. Here, we summarize and analyze clinically relevant observations indicating that Golgi fragmentation is associated with the selective loss of Golgi residency for some enzymes and, conversely, with the relocation of some cytoplasmic proteins to the Golgi. The central concept is that ER and Golgi stresses impair giantin docking site but have no impact on the GM130-GRASP65 complex, thus inducing mislocalization of giantin-sensitive enzymes only. This cardinally changes the processing of proteins by eliminating the pathways controlled by the missing enzymes and by activating the processes now driven by the GM130-GRASP65-dependent proteins. This type of Golgi disorganization is different from the one induced by the cytoskeleton alteration, which despite Golgi de-centralization, neither impairs function of golgins nor alters trafficking.
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Affiliation(s)
- A Petrosyan
- College of Medicine, Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5870, USA. .,The Nebraska Center for Integrated Biomolecular Communication, Lincoln, NE 68588, USA.,The Fred and Pamela Buffett Cancer Center, Omaha, NE 68106, USA
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Frisbie CP, Lushnikov AY, Krasnoslobodtsev AV, Riethoven JJM, Clarke JL, Stepchenkova EI, Petrosyan A. Post-ER Stress Biogenesis of Golgi Is Governed by Giantin. Cells 2019; 8:E1631. [PMID: 31847122 PMCID: PMC6953117 DOI: 10.3390/cells8121631] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 12/05/2019] [Accepted: 12/09/2019] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND The Golgi apparatus undergoes disorganization in response to stress, but it is able to restore compact and perinuclear structure under recovery. This self-organization mechanism is significant for cellular homeostasis, but remains mostly elusive, as does the role of giantin, the largest Golgi matrix dimeric protein. METHODS In HeLa and different prostate cancer cells, we used the model of cellular stress induced by Brefeldin A (BFA). The conformational structure of giantin was assessed by proximity ligation assay and atomic force microscopy. The post-BFA distribution of Golgi resident enzymes was examined by 3D SIM high-resolution microscopy. RESULTS We detected that giantin is rather flexible than an extended coiled-coil dimer and BFA-induced Golgi disassembly was associated with giantin monomerization. A fusion of the nascent Golgi membranes after BFA washout is forced by giantin re-dimerization via disulfide bond in its luminal domain and assisted by Rab6a GTPase. GM130-GRASP65-dependent enzymes are able to reach the nascent Golgi membranes, while giantin-sensitive enzymes appeared at the Golgi after its complete recovery via direct interaction of their cytoplasmic tail with N-terminus of giantin. CONCLUSION Post-stress recovery of Golgi is conducted by giantin dimer and Golgi proteins refill membranes according to their docking affiliation rather than their intra-Golgi location.
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Affiliation(s)
- Cole P. Frisbie
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5870, USA;
| | - Alexander Y. Lushnikov
- Nanoimaging Core Facility, University of Nebraska Medical Center, Omaha, NE 68198-6025, USA; (A.Y.L.); (A.V.K.)
| | - Alexey V. Krasnoslobodtsev
- Nanoimaging Core Facility, University of Nebraska Medical Center, Omaha, NE 68198-6025, USA; (A.Y.L.); (A.V.K.)
- Department of Physics, University of Nebraska-Omaha, Omaha, NE 68182-0266, USA
| | - Jean-Jack M. Riethoven
- Center for Biotechnology, University of Nebraska-Lincoln, Lincoln, NE 68588-0665, USA;
- The Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, USA;
| | - Jennifer L. Clarke
- The Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, USA;
- Department of Statistics, University of Nebraska-Lincoln, Lincoln, NE 68583-0963, USA
| | - Elena I. Stepchenkova
- Vavilov Institute of General Genetics, Saint-Petersburg Branch, Russian Academy of Sciences, Saint-Petersburg 199034, Russia;
- Department of Genetics, Saint-Petersburg State University, Saint-Petersburg 199034, Russia
| | - Armen Petrosyan
- Department of Biochemistry and Molecular Biology, University of Nebraska Medical Center, Omaha, NE 68198-5870, USA;
- The Nebraska Center for Integrated Biomolecular Communication, University of Nebraska-Lincoln, Lincoln, NE 68588-0304, USA;
- The Fred and Pamela Buffett Cancer Center, Omaha, NE 68198-5870, USA
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Petrosyan A, Ali MF, Cheng PW. Keratin 1 plays a critical role in golgi localization of core 2 N-acetylglucosaminyltransferase M via interaction with its cytoplasmic tail. J Biol Chem 2015; 290:6256-69. [PMID: 25605727 PMCID: PMC4358263 DOI: 10.1074/jbc.m114.618702] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 01/14/2015] [Indexed: 11/06/2022] Open
Abstract
Core 2 N-acetylglucosaminyltransferase 2/M (C2GnT-M) synthesizes all three β6GlcNAc branch structures found in secreted mucins. Loss of C2GnT-M leads to development of colitis and colon cancer. Recently we have shown that C2GnT-M targets the Golgi at the Giantin site and is recycled by binding to non-muscle myosin IIA, a motor protein, via the cytoplasmic tail (CT). But how this enzyme is retained in the Golgi is not known. Proteomics analysis identifies keratin type II cytoskeletal 1 (KRT1) as a protein pulled down with anti-c-Myc antibody or C2GnT-M CT from the lysate of Panc1 cells expressing bC2GnT-M tagged with c-Myc. Yeast two-hybrid analysis shows that the rod domain of KRT1 interacts directly with the WKR(6) motif in the C2GnT-M CT. Knockdown of KRT1 does not affect Golgi morphology but increases the interaction of C2GnT-M with non-muscle myosin IIA and its transportation to the endoplasmic reticulum, ubiquitination, and degradation. During Golgi recovery after brefeldin A treatment, C2GnT-M forms a complex with Giantin before KRT1, demonstrating CT-mediated sequential events of Golgi targeting and retention of C2GnT-M. In HeLa cells transiently expressing C2GnT-M-GFP, knockdown of KRT1 does not affect Golgi morphology but leaves C2GnT-M outside of the Golgi, resulting in the formation of sialyl-T antigen. Interaction of C2GnT-M and KRT1 was also detected in the goblet cells of human colon epithelial tissue and primary culture of colonic epithelial cells. The results indicate that glycosylation and thus the function of glycoconjugates can be regulated by a protein that helps retain a glycosyltransferase in the Golgi.
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Affiliation(s)
- Armen Petrosyan
- From the VA Nebraska-Western Iowa Health Care System, Department of Research Service, Omaha, Nebraska 68105 and Department of Biochemistry and Molecular Biology, College of Medicine and
| | - Mohamed F Ali
- From the VA Nebraska-Western Iowa Health Care System, Department of Research Service, Omaha, Nebraska 68105 and Department of Biochemistry and Molecular Biology, College of Medicine and
| | - Pi-Wan Cheng
- From the VA Nebraska-Western Iowa Health Care System, Department of Research Service, Omaha, Nebraska 68105 and Department of Biochemistry and Molecular Biology, College of Medicine and Eppley Institute for Research in Cancer and Allied Diseases, University of Nebraska Medical Center, Omaha, Nebraska 68198
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Eckert ESP, Reckmann I, Hellwig A, Röhling S, El-Battari A, Wieland FT, Popoff V. Golgi phosphoprotein 3 triggers signal-mediated incorporation of glycosyltransferases into coatomer-coated (COPI) vesicles. J Biol Chem 2014; 289:31319-29. [PMID: 25246532 PMCID: PMC4223332 DOI: 10.1074/jbc.m114.608182] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Indexed: 12/30/2022] Open
Abstract
Newly synthesized membrane and secreted proteins undergo a series of posttranslational modifications in the Golgi apparatus, including attachment of carbohydrate moieties. The final structure of so-formed glycans is determined by the order of execution of the different glycosylation steps, which seems intimately related to the spatial distribution of glycosyltransferases and glycosyl hydrolases within the Golgi apparatus. How cells achieve an accurate localization of these enzymes is not completely understood but might involve dynamic processes such as coatomer-coated (COPI) vesicle-mediated trafficking. In yeast, this transport is likely to be regulated by vacuolar protein sorting 74 (Vps74p), a peripheral Golgi protein able to interact with COPI coat as well as with a binding motif present in the cytosolic tails of some mannosyltransferases. Recently, Golgi phosphoprotein 3 (GOLPH3), the mammalian homolog of Vps74, has been shown to control the Golgi localization of core 2 N-acetylglucosamine-transferase 1. Here, we highlight a role of GOLPH3 in the spatial localization of α-2,6-sialyltransferase 1. We show, for the first time, that GOLPH3 supports incorporation of both core 2 N-acetylglucosamine-transferase 1 and α-2,6-sialyltransferase 1 into COPI vesicles. Depletion of GOLPH3 altered the subcellular localization of these enzymes. In contrast, galactosyltransferase, an enzyme that does not interact with GOLPH3, was neither incorporated into COPI vesicles nor was dependent on GOLPH3 for proper localization.
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Affiliation(s)
- Elias S P Eckert
- From the Heidelberg University Biochemistry Center (BZH), INF 328 and
| | - Ingeborg Reckmann
- From the Heidelberg University Biochemistry Center (BZH), INF 328 and
| | - Andrea Hellwig
- Interdisciplinary Center for Neurosciences (IZN), INF 364, Heidelberg University, 69120 Heidelberg, Germany and
| | - Simone Röhling
- From the Heidelberg University Biochemistry Center (BZH), INF 328 and
| | - Assou El-Battari
- INSERM UMR 911, Aix-Marseille Université, Centre de Recherche en Oncobiologie et Oncopharmacologie (CR02), 13284 Marseille, France
| | - Felix T Wieland
- From the Heidelberg University Biochemistry Center (BZH), INF 328 and
| | - Vincent Popoff
- From the Heidelberg University Biochemistry Center (BZH), INF 328 and
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Protein-Protein Interactions: Gene Acronym Redundancies and Current Limitations Precluding Automated Data Integration. Proteomes 2013; 1:3-24. [PMID: 28250396 PMCID: PMC5314489 DOI: 10.3390/proteomes1010003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 05/16/2013] [Accepted: 05/21/2013] [Indexed: 12/31/2022] Open
Abstract
Understanding protein interaction networks and their dynamic changes is a major challenge in modern biology. Currently, several experimental and in silico approaches allow the screening of protein interactors in a large-scale manner. Therefore, the bulk of information on protein interactions deposited in databases and peer-reviewed published literature is constantly growing. Multiple databases interfaced from user-friendly web tools recently emerged to facilitate the task of protein interaction data retrieval and data integration. Nevertheless, as we evidence in this report, despite the current efforts towards data integration, the quality of the information on protein interactions retrieved by in silico approaches is frequently incomplete and may even list false interactions. Here we point to some obstacles precluding confident data integration, with special emphasis on protein interactions, which include gene acronym redundancies and protein synonyms. Three human proteins (choline kinase, PPIase and uromodulin) and three different web-based data search engines focused on protein interaction data retrieval (PSICQUIC, DASMI and BIPS) were used to explain the potential occurrence of undesired errors that should be considered by researchers in the field. We demonstrate that, despite the recent initiatives towards data standardization, manual curation of protein interaction networks based on literature searches are still required to remove potential false positives. A three-step workflow consisting of: (i) data retrieval from multiple databases, (ii) peer-reviewed literature searches, and (iii) data curation and integration, is proposed as the best strategy to gather updated information on protein interactions. Finally, this strategy was applied to compile bona fide information on human DREAM protein interactome, which constitutes liable training datasets that can be used to improve computational predictions.
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RNAi screening reveals a large signaling network controlling the Golgi apparatus in human cells. Mol Syst Biol 2013; 8:629. [PMID: 23212246 PMCID: PMC3542528 DOI: 10.1038/msb.2012.59] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Accepted: 10/11/2012] [Indexed: 12/11/2022] Open
Abstract
RNAi screening and automated image analysis reveal 180 kinases and phosphatases regulating the organization of the Golgi apparatus. Most of these genes also control the expression of specific glycans, pointing to a web of interactions between signaling cascades and glycosylation at the Golgi. ![]()
Golgi organization was probed with three markers of different Golgi compartments and quantitative morphological analysis. Knockdowns of ∼20% of all known kinases and phosphatases affected the Golgi globally or in a compartment-specific manner, and were comparable in degree to the depletion of known membrane traffic regulators such as SNAREs. Several cell surface receptors, their cognate ligands and downstream effectors regulate Golgi organization, suggesting a large regulatory network. Most signaling genes affected both Golgi morphology and the expression of specific glycans.
The Golgi apparatus has many important physiological functions, including sorting of secretory cargo and biosynthesis of complex glycans. These functions depend on the intricate and compartmentalized organization of the Golgi apparatus. To investigate the mechanisms that regulate Golgi architecture, we developed a quantitative morphological assay using three different Golgi compartment markers and quantitative image analysis, and performed a kinome- and phosphatome-wide RNAi screen in HeLa cells. Depletion of 159 signaling genes, nearly 20% of genes assayed, induced strong and varied perturbations in Golgi morphology. Using bioinformatics data, a large regulatory network could be constructed. Specific subnetworks are involved in phosphoinositides regulation, acto-myosin dynamics and mitogen activated protein kinase signaling. Most gene depletion also affected Golgi functions, in particular glycan biosynthesis, suggesting that signaling cascades can control glycosylation directly at the Golgi level. Our results provide a genetic overview of the signaling pathways that control the Golgi apparatus in human cells.
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Petrosyan A, Cheng PW. A non-enzymatic function of Golgi glycosyltransferases: mediation of Golgi fragmentation by interaction with non-muscle myosin IIA. Glycobiology 2013; 23:690-708. [PMID: 23396488 DOI: 10.1093/glycob/cwt009] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The Golgi apparatus undergoes morphological changes under stress or malignant transformation, but the precise mechanisms are not known. We recently showed that non-muscle myosin IIA (NMIIA) binds to the cytoplasmic tail of Core 2 N-acetylglucosaminyltransferase mucus-type (C2GnT-M) and transports it to the endoplasmic reticulum for recycling. Here, we report that Golgi fragmentation induced by brefeldin A (BFA) or coatomer protein (β-COP) knockdown (KD) in Panc1-bC2GnT-M (c-Myc) cells is accompanied by the increased association of NMIIA with C2GnT-M and its degradation by proteasomes. Golgi fragmentation is prevented by inhibition or KD of NMIIA. Using multiple approaches, we have shown that the speed of BFA-induced Golgi fragmentation is positively correlated with the levels of this enzyme in the Golgi. The observation is reproduced in LNCaP cells which express high levels of two endogenous glycosyltransferases--C2GnT-L and β-galactoside α2,3 sialyltransferase 1. NMIIA is found to form complexes with these two enzymes but not Golgi matrix proteins. The KD of both enzymes or the prevention of Golgi glycosyltransferases from exiting endoplasmic reticulum reduced Golgi-associated NMIIA and decreased the BFA-induced fragmentation. Interestingly, the fragmented Golgi detected in colon cancer HT-29 cells can be restored to a compact morphology after inhibition or KD of NMIIA. The Golgi disorganization induced by the microtubule or actin destructive agent is NMIIA-independent and does not affect the levels of glycosyltransferases. We conclude that NMIIA interacts with Golgi residential but not matrix proteins, and this interaction is responsible for Golgi fragmentation induced by β-COP KD or BFA treatment. This is a novel non-enzymatic function of Golgi glycosyltransferases.
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Affiliation(s)
- Armen Petrosyan
- Department of Research Service, VA Nebraska-Western Iowa Health Care System, Omaha, NE 68105 USA
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Ali MF, Chachadi VB, Petrosyan A, Cheng PW. Golgi phosphoprotein 3 determines cell binding properties under dynamic flow by controlling Golgi localization of core 2 N-acetylglucosaminyltransferase 1. J Biol Chem 2012; 287:39564-77. [PMID: 23027862 DOI: 10.1074/jbc.m112.346528] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Core 2 N-acetylglucosaminyltransferase 1 (C2GnT1) is a key enzyme participating in the synthesis of core 2-associated sialyl Lewis x (C2-O-sLe(x)), a ligand involved in selectin-mediated leukocyte trafficking and cancer metastasis. To accomplish that, C2GnT1 needs to be localized to the Golgi and this step requires interaction of its cytoplasmic tail (CT) with a protein that has not been identified. Employing C2GnT1 CT as the bait to perform a yeast two-hybrid screen, we have identified Golgi phosphoprotein 3 (GOLPH3) as a principal candidate protein that interacts with C2GnT1 and demonstrated that C2GnT1 binds to GOLPH3 via the LLRRR(9) sequence in the CT. Confocal fluorescence microscopic analysis shows substantial Golgi co-localization of C2GnT1 and GOLPH3. Upon GOLPH3 knockdown, C2GnT1 is found mainly in the endoplasmic reticulum and decorated with complex-type N-glycans, indicating that the enzyme has been transported to the Golgi but is not retained. Also, we have found that a recombinant protein consisting of C2GnT1 CT(1-16)-Leu(17-32)-Gly(33-42)-GFP is localized to the Golgi although the same construct with mutated CT (AAAAA(9)) is not. The data demonstrate that the C2GnT1 CT is necessary and sufficient for Golgi localization of C2GnT1. Furthermore, GOLPH3 knockdown results in reduced synthesis of C2-O-sLe(x) associated with P-selectin glycoprotein ligand-1, reduced cell tethering to and rolling on immobilized P- or E-selectin, and compromised E-selectin-induced activation of spleen tyrosine kinase and cell adhesion to intercellular adhesion molecule-1 under dynamic flow. Our results reveal that GOLPH3 can regulate cell-cell interaction by controlling Golgi retention of C2GnT1.
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Affiliation(s)
- Mohamed F Ali
- Department of Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, Nebraska 68105, USA
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Petrosyan A, Ali MF, Verma SK, Cheng H, Cheng PW. Non-muscle myosin IIA transports a Golgi glycosyltransferase to the endoplasmic reticulum by binding to its cytoplasmic tail. Int J Biochem Cell Biol 2012; 44:1153-65. [PMID: 22525330 PMCID: PMC4011501 DOI: 10.1016/j.biocel.2012.04.004] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2011] [Revised: 03/14/2012] [Accepted: 04/04/2012] [Indexed: 12/18/2022]
Abstract
The mechanism of the Golgi-to-ER transport of Golgi glycosyltransferases is not clear. We utilize a cell line expressing the core 2 N-acetylglucosaminyltransferase-M (C2GnT-M) tagged with c-Myc to explore this mechanism. By immunoprecipitation using anti-c-Myc antibodies coupled with proteomics analysis, we have identified several proteins including non-muscle myosin IIA (NMIIA), heat shock protein (HSP)-70 and ubiquitin activating enzyme E1 in the immunoprecipitate. Employing yeast-two-hybrid analysis and pulldown experiments, we show that the C-terminal region of the NMIIA heavy chain binds to the 1-6 amino acids in the cytoplasmic tail of C2GnT-M. We have found that NMIIA co-localizes with C2GnT-M at the periphery of the Golgi. In addition, inhibition or knockdown of NMIIA prevents the brefeldin A-induced collapse of the Golgi as shown by the inhibition of the migration of both Giantin, a Golgi matrix protein, and C2GnT-M, a Golgi non-matrix protein, to the ER. In contrast, knockdown of HSP70 retains Giantin in the Golgi but moves C2GnT-M to the ER, a process also blocked by inhibition or knockdown of NMIIA. Also, the intracellular distribution of C2GnT-M is not affected by knockdown of β-coatomer protein with or without inhibition of HSPs, suggesting that the Golgi-to-ER trafficking of C2GnT-M does not depend on coat protein complex-I. Further, inhibition of proteasome results in accumulation of ubiquitinated C2GnT-M, suggesting its degradation by proteasome. Therefore, NMIIA and not coat protein complex-I is responsible for transporting the Golgi glycosyltransferase to the ER for proteasomal degradation. The data suggest that NMIIA is involved in the Golgi remodeling.
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Affiliation(s)
- Armen Petrosyan
- Omaha Western Iowa Health System, VA Service, Department of Veterans Affairs Medical Center, Omaha, NE, USA
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Pruunsild P, Timmusk T. Subcellular localization and transcription regulatory potency of KCNIP/Calsenilin/DREAM/KChIP proteins in cultured primary cortical neurons do not provide support for their role in CRE-dependent gene expression. J Neurochem 2012; 123:29-43. [PMID: 22612322 DOI: 10.1111/j.1471-4159.2012.07796.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
KCNIP3/KChIP3 (voltage-dependent K+ channel interacting protein 3), alias Calsenilin and downstream regulatory element antagonist modulator (DREAM), is a multifunctional protein that modulates A-type potassium channels, affects processing of amyloid precursor protein and regulates transcription. KCNIP3 has been described to negatively influence the activity of CREB (cAMP/Ca(2+)-response element binding protein), an essential factor in neuronal activity-dependent gene expression regulation. However, reports on intracellular localization of KCNIP3 in neurons are diverse and necessitate additional analyses of distribution of KCNIPs in cells to clarify the potential of KCNIP3 to fulfill its functions in different cell compartments. Here, we examined localization of the entire family of highly similar KCNIP proteins in neuronal cells and show that over-expressed isoforms of KCNIP1/KChIP1, KCNIP2/KChIP2, KCNIP3/KChIP3, and KCNIP4/KChIP4 had varied, yet partially overlapping subcellular localization. In addition, although some of the over-expressed KCNIP isoforms localized to the nucleus, endogenous KCNIPs were not detected in nuclei of rat primary cortical neurons. Moreover, we analyzed the role of KCNIP proteins in cAMP/Ca(2+)-response element (CRE)-dependent transcription by luciferase reporter assay and electrophoretic mobility shift assay and report that our results do not support the role for KCNIPs, including DREAM/Calsenilin/KChIP3, in modulation of CREB-mediated transcription in neurons.
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Affiliation(s)
- Priit Pruunsild
- Department of Gene Technology, Tallinn University of Technology, Estonia.
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Rivas M, Villar D, González P, Dopazo XM, Mellstrom B, Naranjo JR. Building the DREAM interactome. SCIENCE CHINA-LIFE SCIENCES 2011; 54:786-92. [DOI: 10.1007/s11427-011-4196-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Accepted: 06/07/2011] [Indexed: 12/28/2022]
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Takematsu H, Yamamoto H, Naito-Matsui Y, Fujinawa R, Tanaka K, Okuno Y, Tanaka Y, Kyogashima M, Kannagi R, Kozutsumi Y. Quantitative transcriptomic profiling of branching in a glycosphingolipid biosynthetic pathway. J Biol Chem 2011; 286:27214-24. [PMID: 21665948 DOI: 10.1074/jbc.m111.234526] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Cellular biosynthesis of macromolecules often involves highly branched enzyme pathways, thus cellular regulation of such pathways could be rather difficult. To understand the regulatory mechanism, a systematic approach could be useful. We genetically analyzed a branched biosynthetic pathway for glycosphingolipid (GSL) GM1 using correlation index-based responsible enzyme gene screening (CIRES), a novel quantitative phenotype-genotype correlation analysis. CIRES utilizes transcriptomic profiles obtained from multiple cells. Among a panel of B cell lines, expression of GM1 was negatively correlated with and suppressed by gene expression of CD77 synthase (CD77Syn), whereas no significant positive correlation was found for enzymes actually biosynthesizing GM1. Unexpectedly, a GM1-suppressive phenotype was also observed in the expression of catalytically inactive CD77Syn, ruling out catalytic consumption of lactosylceramide (LacCer) as the main cause for such negative regulation. Rather, CD77Syn seemed to limit other branching reaction(s) by targeting LacCer synthase (LacCerSyn), a proximal enzyme in the pathway, because they were closely localized in the Golgi apparatus and formed a complex. Moreover, turnover of LacCerSyn was accelerated upon CD77Syn expression to globally change the GSL species expressed. Collectively, these data suggest that transcriptomic assessment of macromolecule biosynthetic pathways can disclose a global regulatory mechanism(s) even when unexpected.
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Affiliation(s)
- Hiromu Takematsu
- Laboratory of Membrane Biochemistry and Biophysics, Graduate School of Biostudies, Kyoto University, Sakyo, Kyoto 606-8501, Japan.
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Maccioni HJF, Quiroga R, Ferrari ML. Cellular and molecular biology of glycosphingolipid glycosylation. J Neurochem 2011; 117:589-602. [PMID: 21371037 DOI: 10.1111/j.1471-4159.2011.07232.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Brain tissue is characterized by its high glycosphingolipid content, particularly those containing sialic acid (gangliosides). As a result of this observation, brain tissue was a focus for studies leading to the characterization of the enzymes participating in ganglioside biosynthesis, and their participation in driving the compositional changes that occur in glycolipid expression during brain development. Later on, this focus shifted to the study of cellular aspects of the synthesis, which lead to the identification of the site of synthesis in the neuronal soma and their axonal transport toward the periphery. In this review article, we will focus in subcellular aspects of the biosynthesis of glycosphingolipid oligosaccharides, particularly the mechanisms underlying the trafficking of glycosphingolipid glycosyltransferases from the endoplasmic reticulum to the Golgi, those that promote their retention in the Golgi and those that participate in their topological organization as part of the complex membrane bound machinery for the synthesis of glycosphingolipids.
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Affiliation(s)
- Hugo J F Maccioni
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC (UNC-CONICET), Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.
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Maccioni HJF, Quiroga R, Spessott W. Organization of the synthesis of glycolipid oligosaccharides in the Golgi complex. FEBS Lett 2011; 585:1691-8. [PMID: 21420403 DOI: 10.1016/j.febslet.2011.03.030] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 03/11/2011] [Accepted: 03/14/2011] [Indexed: 11/28/2022]
Abstract
Glycolipids constitute a complex family of amphipathic molecules structurally characterized by a hydrophilic mono- or oligo-saccharide moiety linked to a hydrophobic ceramide moiety. Due to their asymmetric distribution in cell membranes, exposing the saccharide moiety to the extracytoplasmic side of the cell, glycolipids participate in a variety of cell-cell and cell-ligand interactions. Here we summarize aspects of the cell biology of the stepwise synthesis of the saccharide moiety in the Golgi complex of cells from vertebrates. In particular we refer to the participant glycosyltransferases, with emphasis on their trafficking along the secretory pathway, their retention and organization in the Golgi complex membranes and their dependence on the Golgi complex ultra structural organization for proper function.
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Affiliation(s)
- Hugo J F Maccioni
- Centro de Investigaciones en Química Biológica de Córdoba, CIQUIBIC (UNC-CONICET), Departamento de Química Biológica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.
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Tu L, Banfield DK. Localization of Golgi-resident glycosyltransferases. Cell Mol Life Sci 2010; 67:29-41. [PMID: 19727557 PMCID: PMC11115592 DOI: 10.1007/s00018-009-0126-z] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Revised: 07/30/2009] [Accepted: 08/04/2009] [Indexed: 10/20/2022]
Abstract
For many glycosyltransferases, the information that instructs Golgi localization is located within a relatively short sequence of amino acids in the N-termini of these proteins comprising: the cytoplasmic tail, the transmembrane spanning region, and the stem region (CTS). Also, one enzyme may be more reliant on a particular region in the CTS for its localization than another. The predominance of these integral membrane proteins in the Golgi has seen these enzymes become central players in the development of membrane trafficking models of transport within this organelle. It is now understood that the means by which the characteristic distributions of glycosyltransferases arise within the subcompartments of the Golgi is inextricably linked to the mechanisms that cells employ to direct the flow of proteins and lipids within this organelle.
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Affiliation(s)
- Linna Tu
- Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, People’s Republic of China
| | - David Karl Banfield
- Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, People’s Republic of China
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Christiansen D, Milland J, Dodson HC, Lazarus BD, Sandrin MS. The cytoplasmic and transmembrane domains of secretor type alpha1,2fucosyltransferase confer atypical cellular localisation. J Mol Recognit 2009; 22:250-4. [PMID: 19165762 DOI: 10.1002/jmr.939] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Carbohydrate structures influence many aspects of cell biology. Manipulating the glycosyltransferase enzymes, that sequentially add carbohydrate moieties to proteins and lipids as they pass through the Golgi and secretory pathway, can alter these carbohydrate epitopes. We previously demonstrated that the eight amino acid cytoplasmic tail of alpha1,2fucosyltransferase (FT) contained a sequence for Golgi localisation. In this study, we examined the localisation of the closely related secretor type alpha1,2fucosyltransferase (Sec) which has a smaller, yet apparently unrelated, five amino acid cytoplasmic tail. In contrast to the Golgi localisation of FT, Sec displayed atypical cytoplasmic vesicular-like staining. However, replacing just the five amino acid tail of Sec with FT was sufficient to relocalise the enzyme to a perinuclear region with Golgi-like staining. The biological significance of this relocalisation was this chimaeric enzyme was more effective than FT at competing for N-Acetyl-lactosamine and thus was superior in reducing expression of the Galalpha(1,3)Gal xenoepitope.
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Affiliation(s)
- Dale Christiansen
- Department of Surgery, The University of Melbourne, Austin Health/Northern Health, Heidelberg, Victoria 3084, Australia
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