1
|
Wawrzkiewicz-Jałowiecka A, Lalik A, Lukasiak A, Richter-Laskowska M, Trybek P, Ejfler M, Opałka M, Wardejn S, Delfino DV. Potassium Channels, Glucose Metabolism and Glycosylation in Cancer Cells. Int J Mol Sci 2023; 24:ijms24097942. [PMID: 37175655 PMCID: PMC10178682 DOI: 10.3390/ijms24097942] [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: 03/29/2023] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/15/2023] Open
Abstract
Potassium channels emerge as one of the crucial groups of proteins that shape the biology of cancer cells. Their involvement in processes like cell growth, migration, or electric signaling, seems obvious. However, the relationship between the function of K+ channels, glucose metabolism, and cancer glycome appears much more intriguing. Among the typical hallmarks of cancer, one can mention the switch to aerobic glycolysis as the most favorable mechanism for glucose metabolism and glycome alterations. This review outlines the interconnections between the expression and activity of potassium channels, carbohydrate metabolism, and altered glycosylation in cancer cells, which have not been broadly discussed in the literature hitherto. Moreover, we propose the potential mediators for the described relations (e.g., enzymes, microRNAs) and the novel promising directions (e.g., glycans-orinented drugs) for further research.
Collapse
Affiliation(s)
- Agata Wawrzkiewicz-Jałowiecka
- Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, 44-100 Gliwice, Poland
| | - Anna Lalik
- Department of Systems Biology and Engineering, Silesian University of Technology, 44-100 Gliwice, Poland
- Biotechnology Center, Silesian University of Technology, 44-100 Gliwice, Poland
| | - Agnieszka Lukasiak
- Department of Physics and Biophysics, Institute of Biology, Warsaw University of Life Sciences, 02-776 Warsaw, Poland
| | - Monika Richter-Laskowska
- The Centre for Biomedical Engineering, Łukasiewicz Research Network-Krakow Institute of Technology, 30-418 Krakow, Poland
| | - Paulina Trybek
- Institute of Physics, University of Silesia in Katowice, 41-500 Chorzów, Poland
| | - Maciej Ejfler
- Faculty of Automatic Control, Electronics and Computer Science, Silesian University of Technology, 44-100 Gliwice, Poland
| | - Maciej Opałka
- Faculty of Automatic Control, Electronics and Computer Science, Silesian University of Technology, 44-100 Gliwice, Poland
| | - Sonia Wardejn
- Faculty of Automatic Control, Electronics and Computer Science, Silesian University of Technology, 44-100 Gliwice, Poland
| | - Domenico V Delfino
- Section of Pharmacology, Department of Medicine and Surgery, University of Perugia, 06129 Perugia, Italy
| |
Collapse
|
2
|
Issa FA, Hall MK, Hatchett CJ, Weidner DA, Fiorenza AC, Schwalbe RA. Compromised N-Glycosylation Processing of Kv3.1b Correlates with Perturbed Motor Neuron Structure and Locomotor Activity. BIOLOGY 2021; 10:486. [PMID: 34070741 PMCID: PMC8229559 DOI: 10.3390/biology10060486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 05/26/2021] [Accepted: 05/27/2021] [Indexed: 11/17/2022]
Abstract
Neurological difficulties commonly accompany individuals suffering from congenital disorders of glycosylation, resulting from defects in the N-glycosylation pathway. Vacant N-glycosylation sites (N220 and N229) of Kv3, voltage-gated K+ channels of high-firing neurons, deeply perturb channel activity in neuroblastoma (NB) cells. Here we examined neuron development, localization, and activity of Kv3 channels in wildtype AB zebrafish and CRISPR/Cas9 engineered NB cells, due to perturbations in N-glycosylation processing of Kv3.1b. We showed that caudal primary (CaP) motor neurons of zebrafish spinal cord transiently expressing fully glycosylated (WT) Kv3.1b have stereotypical morphology, while CaP neurons expressing partially glycosylated (N220Q) Kv3.1b showed severe maldevelopment with incomplete axonal branching and extension around the ventral musculature. Consequently, larvae expressing N220Q in CaP neurons had impaired swimming locomotor activity. We showed that replacement of complex N-glycans with oligomannose attached to Kv3.1b and at cell surface lessened Kv3.1b dispersal to outgrowths by altering the number, size, and density of Kv3.1b-containing particles in membranes of rat neuroblastoma cells. Opening and closing rates were slowed in Kv3 channels containing Kv3.1b with oligomannose, instead of complex N-glycans, which suggested a reduction in the intrinsic dynamics of the Kv3.1b α-subunit. Thus, N-glycosylation processing of Kv3.1b regulates neuronal development and excitability, thereby controlling motor activity.
Collapse
Affiliation(s)
- Fadi A. Issa
- Department of Biology, East Carolina University, Greenville, NC 27858, USA;
| | - M. Kristen Hall
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA; (M.K.H.); (C.J.H.); (A.C.F.)
| | - Cody J. Hatchett
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA; (M.K.H.); (C.J.H.); (A.C.F.)
| | - Douglas A. Weidner
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA;
| | - Alexandria C. Fiorenza
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA; (M.K.H.); (C.J.H.); (A.C.F.)
| | - Ruth A. Schwalbe
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, NC 27834, USA; (M.K.H.); (C.J.H.); (A.C.F.)
| |
Collapse
|
3
|
Burand AJ, Stucky CL. Fabry disease pain: patient and preclinical parallels. Pain 2021; 162:1305-1321. [PMID: 33259456 PMCID: PMC8054551 DOI: 10.1097/j.pain.0000000000002152] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 10/31/2020] [Accepted: 11/18/2020] [Indexed: 02/07/2023]
Abstract
ABSTRACT Severe neuropathic pain is a hallmark of Fabry disease, a genetic disorder caused by a deficiency in lysosomal α-galactosidase A. Pain experienced by these patients significantly impacts their quality of life and ability to perform everyday tasks. Patients with Fabry disease suffer from peripheral neuropathy, sensory abnormalities, acute pain crises, and lifelong ongoing pain. Although treatment of pain through medication and enzyme replacement therapy exists, pain persists in many of these patients. Some has been learned in the past decades regarding clinical manifestations of pain in Fabry disease and the pathological effects of α-galactosidase A insufficiency in neurons. Still, it is unclear how pain and sensory abnormalities arise in patients with Fabry disease and how these can be targeted with therapeutics. Our knowledge is limited in part due to the lack of adequate preclinical models to study the disease. This review will detail the types of pain, sensory abnormalities, influence of demographics on pain, and current strategies to treat pain experienced by patients with Fabry disease. In addition, we discuss the current knowledge of Fabry pain pathogenesis and which aspects of the disease preclinical models accurately recapitulate. Understanding the commonalities and divergences between humans and preclinical models can be used to further interrogate mechanisms causing the pain and sensory abnormalities as well as advance development of the next generation of therapeutics to treat pain in patients with Fabry disease.
Collapse
Affiliation(s)
- Anthony J. Burand
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, United States
| | - Cheryl L. Stucky
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, United States
| |
Collapse
|
4
|
Knockdown of N-Acetylglucosaminyltransferase-II Reduces Matrix Metalloproteinase 2 Activity and Suppresses Tumorigenicity in Neuroblastoma Cell Line. BIOLOGY 2020; 9:biology9040071. [PMID: 32260356 PMCID: PMC7236022 DOI: 10.3390/biology9040071] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 03/30/2020] [Accepted: 03/30/2020] [Indexed: 12/22/2022]
Abstract
Neuroblastoma (NB) development and progression are accompanied by changes in N-glycans attached to proteins. Here, we investigated the role of N-acetylglucosaminyltransferase-II (GnTII, MGAT2) protein substrates in neuroblastoma (NB) cells. MGAT2 was silenced in human BE(2)-C NB (HuNB) cells to generate a novel cell line, HuNB(-MGAT2), lacking complex type N-glycans, as in rat B35 NB cells. Changes in N-glycan types were confirmed by lectin binding assays in both cell lines, and the rescued cell line, HuNB(-/+MGAT2). Western blotting of cells heterologously expressing a voltage-gated K+ channel (Kv3.1b) showed that some hybrid N-glycans of Kv3.1b could be processed to complex type in HuNB(-/+MGAT2) cells. In comparing HuNB and HuNB(-MGAT2) cells, decreased complex N-glycans reduced anchorage-independent cell growth, cell proliferation, and cell invasiveness, while they enhanced cell-cell interactions. Cell proliferation, invasiveness and adhesion of the HuNB(-/+MGAT2) cells were more like the HuNB than HuNB(-MGAT2). Western blotting revealed lower protein levels of MMP-2, EGFR and Gab2 in glycosylation mutant cells relative to parental cells. Gelatin zymography demonstrated that decreased MMP-2 protein activity was related to lowered MMP-2 protein levels. Thus, our results support that decreased complex type N-glycans suppress cell proliferation and cell invasiveness in both NB cell lines via remodeling ECM.
Collapse
|
5
|
Hall MK, Weidner DA, Whitman AA, Schwalbe RA. Lack of complex type N-glycans lessens aberrant neuronal properties. PLoS One 2018; 13:e0199202. [PMID: 29902282 PMCID: PMC6002081 DOI: 10.1371/journal.pone.0199202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 04/25/2018] [Indexed: 01/26/2023] Open
Abstract
Modifications in surface glycans attached to proteins via N-acetylglucosamine-β1-N-asparagine linkage have been linked to tumor development and progression. These modifications include complex N-glycans with high levels of branching, fucose and sialic acid residues. Previously, we silenced Mgat2 in neuroblastoma (NB) cells, which halted the conversion of hybrid type N-glycans to complex type, to generate a novel cell line, NB_1(-Mgat2). By comparing the aberrant cell properties of the NB_1(-Mgat2) cell line to the parental cell line (NB_1), we investigated the impact of eliminating complex type N-glycans on NB cell behavior. Further, the N-glycosylation pathway in the NB_1(-Mgat2) cell line was rescued by transiently transfecting cells with Mgat2, thus creating the NB_1(-/+Mgat2) cell line. Changes in the N-glycosylation pathway were verified by enhanced binding of E-PHA and L-PHA to proteins in the rescued cell line relative to those of the NB_1(-Mgat2) cell line. Also, western blotting of total membranes from the rescued cell line ectopically expressing a voltage-gated K+ channel (Kv3.1b) revealed that N-glycans of Kv3.1b were processed to complex type. By employment of various cell lines, we demonstrated that reduction of the complex type N-glycans diminished anchorage-independent cell growth, and enhanced cell-cell interactions. Two independent cell invasion assays showed that cell invasiveness was markedly lessened by lowering the levels of complex type N-glycans while cell mobility was only slightly modified. Neurites of NB cells were shortened by the absence of complex type N-glycans. Cell proliferation was reduced in NB cells with lowered levels of complex type N-glycans which resulted from hindered progression through G1+Go phases of the cell cycle. Overall, our results illustrate that reducing the ratio of complex to hybrid types of N-glycans diminishes aberrant NB cell behavior and thereby has a suppressive effect in cell proliferation, and cell dissociation and invasion phases of NB.
Collapse
Affiliation(s)
- M. Kristen Hall
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Douglas A. Weidner
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Austin A. Whitman
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| | - Ruth A. Schwalbe
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, North Carolina, United States of America
| |
Collapse
|
6
|
Hall MK, Weidner DA, Dayal S, Pak E, Murashov AK, Schwalbe RA. Membrane Distribution and Activity of a Neuronal Voltage-Gated K+ Channel is Modified by Replacement of Complex Type N-Glycans with Hybrid Type. ACTA ACUST UNITED AC 2017; 6. [PMID: 30271698 PMCID: PMC6157612 DOI: 10.4172/2168-958x.1000128] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abnormal modifications in N-glycosylation processing are commonly associated with neurological disorders, although the impact of specific N-glycans on neuronal excitability is unknown. By replacement of complex types of N-glycans with hybrid types in neuroblastoma cells, we provide the first study that addresses how distinct N-glycan types impact neuronal excitability. Using CRISPR/Cas9 technology, NB_1, a clonal cell line derived from rat neuroblastoma cells (NB), was modified to create an N-glycosylation mutant cell line, NB_1 (-Mgat2), which expresses predominantly hybrid type N-glycans. Western and lectin blotting, flow cytometry, TIRF and DIC microscopy, and patch clamp studies were conducted. Lectin binding revealed the predominant type of N-glycans expressed in NB_1 (-Mgat2) is hybrid while those of NB and NB_1 are complex. Kv3.1 b-expressing cells with complex N-glycans localized more glycosylated Kv3.1b to the neurites than cells with hybrid N-glycans. Further the absence of N-glycan attachment to Kv3.1b was critical for sub-plasma distribution of Kv3.1b to neurites in primary adult mammalian neurons, along with NB cells. Replacement of complex type N-glycans with hybrid type hindered the opening and closing rates of outward ionic currents of Kv3.1 b-expressing NB cells. The lacks of N-glycan attachment hindered the rates even more but were not significantly different between the NB cell lines. Taken together, our evidence supports N-glycosylation impacts the sub-plasma membrane localization and activity of Kv3.1 b-containing channels. We propose that N-glycosylation processing of Kv3.1 b-containing channels contributes to neuronal excitability, and abnormal modifications in N-glycosylation processing of Kv3.1b could contribute to neurological diseases.
Collapse
Affiliation(s)
- M Kristen Hall
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, USA
| | - Douglas A Weidner
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, Greenville, USA
| | - Sahil Dayal
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, USA
| | - Elena Pak
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, USA
| | - Alexander K Murashov
- Department of Physiology, Brody School of Medicine, East Carolina University, Greenville, USA
| | - Ruth A Schwalbe
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, Greenville, USA
| |
Collapse
|
7
|
Ulăreanu R, Chiriţoiu G, Cojocaru F, Deftu A, Ristoiu V, Stănică L, Mihăilescu DF, Cucu D. N-glycosylation of the transient receptor potential melastatin 8 channel is altered in pancreatic cancer cells. Tumour Biol 2017; 39:1010428317720940. [PMID: 28857015 DOI: 10.1177/1010428317720940] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Transient receptor potential melastatin 8 (TRPM8), a membrane ion channel, is activated by thermal and chemical stimuli. In pancreatic ductal adenocarcinoma, TRPM8 is required for cell migration, proliferation, and senescence and is associated with tumor size and pancreatic ductal adenocarcinoma stages. Although the underlying mechanisms of these processes have yet to be described, this cation-permeable channel has been proposed as an oncological target. In this study, the glycosylation status of the TRPM8 channel was shown to affect cell proliferation, cell migration, and calcium uptake. TRPM8 expressed in the membrane of the Panc-1 pancreatic tumoral cell line is non-glycosylated, whereas human embryonic kidney cells transfected with human TRPM8 overexpress a glycosylated protein. Moreover, our data suggest that Ca2+ uptake is modulated by the glycosylation status of the protein, thus affecting cell proliferation.
Collapse
Affiliation(s)
- Roxana Ulăreanu
- 1 Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Gabriela Chiriţoiu
- 2 Department of Molecular Cell Biology, Institute of Biochemistry, Romanian Academy, Bucharest, Romania
| | - Florentina Cojocaru
- 1 Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Alexandru Deftu
- 1 Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Violeta Ristoiu
- 1 Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Luciana Stănică
- 1 Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Dan F Mihăilescu
- 1 Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| | - Dana Cucu
- 1 Department of Anatomy, Animal Physiology and Biophysics, Faculty of Biology, University of Bucharest, Bucharest, Romania
| |
Collapse
|
8
|
Vicente PC, Kim JY, Ha J, Song M, Lee H, Kim D, Choi J, Park K. Identification and characterization of site‐specific N‐glycosylation in the potassium channel Kv3.1b. J Cell Physiol 2017; 233:549-558. [DOI: 10.1002/jcp.25915] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2016] [Accepted: 03/17/2017] [Indexed: 12/11/2022]
Affiliation(s)
| | - Jin Young Kim
- Biomedical Omics GroupKorea Basic Science InstituteCheongju‐si Chungcheongbuk‐doSouth Korea
| | - Jeong‐Ju Ha
- Department of Physiology, School of MedicineKyung Hee UniversitySeoulSouth Korea
| | - Min‐Young Song
- Department of Physiology, School of MedicineKyung Hee UniversitySeoulSouth Korea
- Biomedical Omics GroupKorea Basic Science InstituteCheongju‐si Chungcheongbuk‐doSouth Korea
| | - Hyun‐Kyung Lee
- Biomedical Omics GroupKorea Basic Science InstituteCheongju‐si Chungcheongbuk‐doSouth Korea
- Graduate School of Analytical Science and TechnologyChungnam National UniversityDaejeonSouth Korea
| | - Dong‐Hyun Kim
- College of PharmacyCatholic University of KoreaBucheonGyeonggi‐DoSouth Korea
| | - Jin‐Sung Choi
- College of PharmacyCatholic University of KoreaBucheonGyeonggi‐DoSouth Korea
| | - Kang‐Sik Park
- Department of Physiology, School of MedicineKyung Hee UniversitySeoulSouth Korea
| |
Collapse
|
9
|
Zhu R, Song E, Hussein A, Kobeissy FH, Mechref Y. Glycoproteins Enrichment and LC-MS/MS Glycoproteomics in Central Nervous System Applications. Methods Mol Biol 2017; 1598:213-227. [PMID: 28508363 DOI: 10.1007/978-1-4939-6952-4_9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Proteins and glycoproteins play important biological roles in central nervous systems (CNS). Qualitative and quantitative evaluation of proteins and glycoproteins expression in CNS is critical to reveal the inherent biomolecular mechanism of CNS diseases. This chapter describes proteomic and glycoproteomic approaches based on liquid chromatography/tandem mass spectrometry (LC-MS or LC-MS/MS) for the qualitative and quantitative assessment of proteins and glycoproteins expressed in CNS. Proteins and glycoproteins, extracted by a mass spectrometry friendly surfactant from CNS samples, were subjected to enzymatic (tryptic) digestion and three down-stream analyses: (1) a nano LC system coupled with a high-resolution MS instrument to achieve qualitative proteomic profile, (2) a nano LC system combined with a triple quadrupole MS to quantify identified proteins, and (3) glycoprotein enrichment prior to LC-MS/MS analysis. Enrichment techniques can be applied to improve coverage of low abundant glycopeptides/glycoproteins. An example described in this chapter is hydrophilic interaction liquid chromatographic (HILIC) enrichment to capture glycopeptides, allowing efficient removal of peptides. The combination of three LC-MS/MS-based approaches is capable of the investigation of large-scale proteins and glycoproteins from CNS with an in-depth coverage, thus offering a full view of proteins and glycoproteins changes in CNS.
Collapse
Affiliation(s)
- Rui Zhu
- Department of Chemistry and Biochemistry, Texas Tech University, Memorial Circle & Boston Ave., Box 41061, Lubbock, TX, 79409-1061, USA
| | - Ehwang Song
- Department of Chemistry and Biochemistry, Texas Tech University, Memorial Circle & Boston Ave., Box 41061, Lubbock, TX, 79409-1061, USA
| | - Ahmed Hussein
- Department of Biotechnology, Institute of Graduate Studies and Research, University of Alexandria, Alexandria, 21526, Egypt
| | - Firas H Kobeissy
- Department of Biochemistry and Molecular Genetics, Faculty of Medicine, American University of Beirut, Beirut, Lebanon.,Department of Psychiatry, Center for Neuroproteomics and Biomarkers Research, University of Florida, Gainesville, FL, USA
| | - Yehia Mechref
- Department of Chemistry and Biochemistry, Texas Tech University, Memorial Circle & Boston Ave., Box 41061, Lubbock, TX, 79409-1061, USA.
| |
Collapse
|
10
|
Huang ZG, Liu HW, Yan ZZ, Wang S, Wang LY, Ding JP. The glycosylation of the extracellular loop of β2 subunits diversifies functional phenotypes of BK Channels. Channels (Austin) 2016; 11:156-166. [PMID: 27690717 DOI: 10.1080/19336950.2016.1243631] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
Large-conductance Ca2+- and voltage-activated potassium (MaxiK or BK) channels are composed of a pore-forming α subunit (Slo) and 4 types of auxiliary β subunits or just a pore-forming α subunit. Although multiple N-linked glycosylation sites in the extracellular loop of β subunits have been identified, very little is known about how glycosylation influences the structure and function of BK channels. Using a combination of site-directed mutagenesis, western blot and patch-clamp recordings, we demonstrated that 3 sites in the extracellular loop of β2 subunit are N-glycosylated (N-X-T/S at N88, N96 and N119). Glycosylation of these sites strongly and differentially regulate gating kinetics, outward rectification, toxin sensitivity and physical association between the α and β2 subunits. We constructed a model and used molecular dynamics (MD) to simulate how the glycosylation facilitates the association of α/β2 subunits and modulates the dimension of the extracellular cavum above the pore of the channel, ultimately to modify biophysical and pharmacological properties of BK channels. Our results suggest that N-glycosylation of β2 subunits plays crucial roles in imparting functional heterogeneity of BK channels, and is potentially involved in the pathological phenotypes of carbohydrate metabolic diseases.
Collapse
Affiliation(s)
- Zhi-Gang Huang
- a Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan , Hubei , China.,b Wuhan Foreign Languages School , Wuhan , Hubei , China
| | - Hao-Wen Liu
- a Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan , Hubei , China
| | - Zhen-Zhen Yan
- a Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan , Hubei , China
| | - Sheng Wang
- a Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan , Hubei , China
| | - Lu-Yang Wang
- c Program in Neurosciences and Mental Health, SickKids Research Institute and Department of Physiology , University of Toronto , Toronto , Ontario , Canada
| | - Jiu-Ping Ding
- a Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology , Huazhong University of Science and Technology , Wuhan , Hubei , China
| |
Collapse
|
11
|
Hall MK, Weidner DA, Zhu Y, Dayal S, Whitman AA, Schwalbe RA. Predominant Expression of Hybrid N-Glycans Has Distinct Cellular Roles Relative to Complex and Oligomannose N-Glycans. Int J Mol Sci 2016; 17:ijms17060925. [PMID: 27304954 PMCID: PMC4926458 DOI: 10.3390/ijms17060925] [Citation(s) in RCA: 8] [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: 03/14/2016] [Revised: 05/02/2016] [Accepted: 06/03/2016] [Indexed: 12/22/2022] Open
Abstract
Glycosylation modulates growth, maintenance, and stress signaling processes. Consequently, altered N-glycosylation is associated with reduced fitness and disease. Therefore, expanding our understanding of N-glycans in altering biological processes is of utmost interest. Herein, clustered regularly interspaced short palindromic repeats/caspase9 (CRISPR/Cas9) technology was employed to engineer a glycosylation mutant Chinese Hamster Ovary (CHO) cell line, K16, which expresses predominantly hybrid type N-glycans. This newly engineered cell line enabled us to compare N-glycan effects on cellular properties of hybrid type N-glycans, to the well-established Pro−5 and Lec1 cell lines, which express complex and oligomannose types of N-glycans, respectively. Lectin binding studies revealed the predominant N-glycan expressed in K16 is hybrid type. Cell dissociation and migration assays demonstrated the greatest strength of cell–cell adhesion and fastest migratory rates for oligomannose N-glycans, and these properties decreased as oligomannose type were converted to hybrid type, and further decreased upon conversion to complex type. Next, we examined the roles of three general types of N-glycans on ectopic expression of E-cadherin, a cell–cell adhesion protein. Microscopy revealed more functional E-cadherin at the cell–cell border when N-glycans were oligomannose and these levels decreased as the oligomannose N-glycans were processed to hybrid and then to complex. Thus, we provide evidence that all three general types of N-glycans impact plasma membrane architecture and cellular properties.
Collapse
Affiliation(s)
- M Kristen Hall
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, 600 Moye Boulevard, Greenville, NC 27834, USA.
| | - Douglas A Weidner
- Department of Microbiology and Immunology, Brody School of Medicine, East Carolina University, 600 Moye Boulevard, Greenville, NC 27834, USA.
| | - Yong Zhu
- Department of Biology, East Carolina University, 1000 E. 5th Street, Greenville, NC 27858, USA.
| | - Sahil Dayal
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, 600 Moye Boulevard, Greenville, NC 27834, USA.
| | - Austin A Whitman
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, 600 Moye Boulevard, Greenville, NC 27834, USA.
| | - Ruth A Schwalbe
- Department of Biochemistry and Molecular Biology, Brody School of Medicine, East Carolina University, 600 Moye Boulevard, Greenville, NC 27834, USA.
| |
Collapse
|
12
|
Glycosylation-dependent activation of epithelial sodium channel by solnatide. Biochem Pharmacol 2015; 98:740-53. [DOI: 10.1016/j.bcp.2015.08.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 08/03/2015] [Indexed: 12/29/2022]
|
13
|
Bao J, Qin L, Cui L, Wang X, Meng Q, Zhu L, Zhang S. Microarray data analysis of neuroblastoma: Expression of SOX2 downregulates the expression of MYCN. Mol Med Rep 2015; 12:6867-72. [PMID: 26398570 DOI: 10.3892/mmr.2015.4311] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 08/04/2015] [Indexed: 11/06/2022] Open
Abstract
The present study aimed to identify the genes directly or indirectly correlated with the amplification of MYCN in neuroblastoma (NB). Microarray data (GSE53371) were downloaded from Gene Expression Omnibus, and included 10 NB cell lines with MYCN amplification and 10 NB cell lines with normal MYCN copy numbers. Differentially expressed genes (DEGs) were identified using the Linear Models for Microarray Data package, and a false discovery rate of <0.05 and |log2FC (fold change)|>1 were selected as cut‑off criteria. Hierarchical clustering analysis and Gene Ontology analysis were respectively performed for the DEGs using the Pheatmap package in R language and The Database for Annotation, Visualization and Integrated Discovery. A protein‑protein interaction network (PPI) was constructed for the DEGs using the Search Tool for the Retrieval of Interacting Genes database. Pathway analysis was performed for the DEGs in the PPI network using the WEB‑based GEne SeT AnaLysis Toolkit. The correlation between MYCN and the key gene associated with MYCN was determined using Pearson's correlation coefficient. In total, 137 downregulated and 35 upregulated DEGs were identified. Functional enrichment analysis indicated that KCNMB4 was involved in the regulation of action potential in neuron term, and the FOS, GLI3 and GLI1 genes were involved in the extracellular matrix‑receptor interaction pathway. The PPI network and correlation analysis revealed that the expression of SOX2 was directly correlated with the expression of MYCN, and the correlation coefficient of SOX2 and MYCN was ‑0.83. Therefore, SOX2, KCNMB4, FOS, GLI3 and GLI1 may be involved in the pathogenesis of NB, with the expression of SOX2 downregulating the expression of MYCN.
Collapse
Affiliation(s)
- Juntao Bao
- Department of Pediatric Surgery, Henan Provincial People's Hospital, Zhengzhou, Henan 450003, P.R. China
| | - Luying Qin
- Nursing College, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Lingling Cui
- College of Public Health, Zhengzhou University, Zhengzhou, Henan 450001, P.R. China
| | - Xiaohui Wang
- Department of Pediatric Surgery, Henan Provincial People's Hospital, Zhengzhou, Henan 450003, P.R. China
| | - Qinglei Meng
- Department of Pediatric Surgery, Henan Provincial People's Hospital, Zhengzhou, Henan 450003, P.R. China
| | - Linchao Zhu
- Department of Pediatric Surgery, Henan Provincial People's Hospital, Zhengzhou, Henan 450003, P.R. China
| | - Shufeng Zhang
- Department of Pediatric Surgery, Henan Provincial People's Hospital, Zhengzhou, Henan 450003, P.R. China
| |
Collapse
|
14
|
Hall MK, Weidner DA, Edwards MAJ, Schwalbe RA. Complex N-Glycans Influence the Spatial Arrangement of Voltage Gated Potassium Channels in Membranes of Neuronal-Derived Cells. PLoS One 2015; 10:e0137138. [PMID: 26348848 PMCID: PMC4562626 DOI: 10.1371/journal.pone.0137138] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 08/12/2015] [Indexed: 01/08/2023] Open
Abstract
The intrinsic electrical properties of a neuron depend on expression of voltage gated potassium (Kv) channel isoforms, as well as their distribution and density in the plasma membrane. Recently, we showed that N-glycosylation site occupancy of Kv3.1b modulated its placement in the cell body and neurites of a neuronal-derived cell line, B35 neuroblastoma cells. To extrapolate this mechanism to other N-glycosylated Kv channels, we evaluated the impact of N-glycosylation occupancy of Kv3.1a and Kv1.1 channels. Western blots revealed that wild type Kv3.1a and Kv1.1 α-subunits had complex and oligomannose N-glycans, respectively, and that abolishment of the N-glycosylation site(s) generated Kv proteins without N-glycans. Total internal reflection fluorescence microscopy images revealed that N-glycans of Kv3.1a contributed to its placement in the cell membrane while N-glycans had no effect on the distribution of Kv1.1. Based on particle analysis of EGFP-Kv proteins in the adhered membrane, glycosylated forms of Kv3.1a, Kv1.1, and Kv3.1b had differences in the number, size or density of Kv protein clusters in the cell membrane of neurites and cell body of B35 cells. Differences were also observed between the unglycosylated forms of the Kv proteins. Cell dissociation assays revealed that cell-cell adhesion was increased by the presence of complex N-glycans of Kv3.1a, like Kv3.1b, whereas cell adhesion was similar in the oligomannose and unglycosylated Kv1.1 subunit containing B35 cells. Our findings provide direct evidence that N-glycans of Kv3.1 splice variants contribute to the placement of these glycoproteins in the plasma membrane of neuronal-derived cells while those of Kv1.1 were absent. Further when the cell membrane distribution of the Kv channel was modified by N-glycans then the cell-cell adhesion properties were altered. Our study demonstrates that N-glycosylation of Kv3.1a, like Kv3.1b, provides a mechanism for the distribution of these proteins to the cell body and outgrowths and thereby can generate different voltage-dependent conductances in these membranes.
Collapse
Affiliation(s)
- M. Kristen Hall
- Department of Biochemistry and Molecular Biology, Brody School of Medicine at East Carolina University, Greenville, North Carolina, 27834, United States of America
| | - Douglas A. Weidner
- Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University, Greenville, North Carolina, 27834, United States of America
| | - Michael A. J. Edwards
- Department of Biochemistry and Molecular Biology, Brody School of Medicine at East Carolina University, Greenville, North Carolina, 27834, United States of America
| | - Ruth A. Schwalbe
- Department of Biochemistry and Molecular Biology, Brody School of Medicine at East Carolina University, Greenville, North Carolina, 27834, United States of America
- * E-mail:
| |
Collapse
|
15
|
Muona M, Berkovic SF, Dibbens LM, Oliver KL, Maljevic S, Bayly MA, Joensuu T, Canafoglia L, Franceschetti S, Michelucci R, Markkinen S, Heron SE, Hildebrand MS, Andermann E, Andermann F, Gambardella A, Tinuper P, Licchetta L, Scheffer IE, Criscuolo C, Filla A, Ferlazzo E, Ahmad J, Ahmad A, Baykan B, Said E, Topcu M, Riguzzi P, King MD, Ozkara C, Andrade DM, Engelsen BA, Crespel A, Lindenau M, Lohmann E, Saletti V, Massano J, Privitera M, Espay AJ, Kauffmann B, Duchowny M, Møller RS, Straussberg R, Afawi Z, Ben-Zeev B, Samocha KE, Daly MJ, Petrou S, Lerche H, Palotie A, Lehesjoki AE. A recurrent de novo mutation in KCNC1 causes progressive myoclonus epilepsy. Nat Genet 2014; 47:39-46. [PMID: 25401298 DOI: 10.1038/ng.3144] [Citation(s) in RCA: 206] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 10/16/2014] [Indexed: 12/14/2022]
Abstract
Progressive myoclonus epilepsies (PMEs) are a group of rare, inherited disorders manifesting with action myoclonus, tonic-clonic seizures and ataxia. We sequenced the exomes of 84 unrelated individuals with PME of unknown cause and molecularly solved 26 cases (31%). Remarkably, a recurrent de novo mutation, c.959G>A (p.Arg320His), in KCNC1 was identified as a new major cause for PME. Eleven unrelated exome-sequenced (13%) and two affected individuals in a secondary cohort (7%) had this mutation. KCNC1 encodes KV3.1, a subunit of the KV3 voltage-gated potassium ion channels, which are major determinants of high-frequency neuronal firing. Functional analysis of the Arg320His mutant channel showed a dominant-negative loss-of-function effect. Ten cases had pathogenic mutations in known PME-associated genes (NEU1, NHLRC1, AFG3L2, EPM2A, CLN6 and SERPINI1). Identification of mutations in PRNP, SACS and TBC1D24 expand their phenotypic spectra to PME. These findings provide insights into the molecular genetic basis of PME and show the role of de novo mutations in this disease entity.
Collapse
Affiliation(s)
- Mikko Muona
- 1] Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland. [2] Folkhälsan Institute of Genetics, Helsinki, Finland. [3] Neuroscience Center, University of Helsinki, Helsinki, Finland. [4] Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
| | - Samuel F Berkovic
- Epilepsy Research Center, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Leanne M Dibbens
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Karen L Oliver
- Epilepsy Research Center, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Snezana Maljevic
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Marta A Bayly
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Tarja Joensuu
- 1] Folkhälsan Institute of Genetics, Helsinki, Finland. [2] Neuroscience Center, University of Helsinki, Helsinki, Finland. [3] Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
| | - Laura Canafoglia
- Department of Neurophysiopathology, C. Besta Foundation Neurological Institute, Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS), Milan, Italy
| | - Silvana Franceschetti
- Department of Neurophysiopathology, C. Besta Foundation Neurological Institute, Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS), Milan, Italy
| | - Roberto Michelucci
- Neurology Unit, IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy
| | - Salla Markkinen
- 1] Folkhälsan Institute of Genetics, Helsinki, Finland. [2] Neuroscience Center, University of Helsinki, Helsinki, Finland. [3] Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
| | - Sarah E Heron
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Michael S Hildebrand
- Epilepsy Research Center, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia
| | - Eva Andermann
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | - Frederick Andermann
- Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada
| | | | - Paolo Tinuper
- 1] Neurology Unit, IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy. [2] Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Laura Licchetta
- 1] Neurology Unit, IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy. [2] Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Ingrid E Scheffer
- 1] Epilepsy Research Center, Department of Medicine, University of Melbourne, Austin Health, Heidelberg, Victoria, Australia. [2] Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia. [3] Department of Pediatrics, Royal Children's Hospital, University of Melbourne, Melbourne, Victoria, Australia
| | - Chiara Criscuolo
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, Federico II University, Naples, Italy
| | - Alessandro Filla
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, Federico II University, Naples, Italy
| | - Edoardo Ferlazzo
- 1] Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy. [2] Regional Epilepsy Center, Bianchi-Melacrino-Morelli Hospital, Reggio Calabria, Italy
| | - Jamil Ahmad
- Department of Biotechnology and Informatics, Balochistan University of Information Technology, Engineering and Management Sciences, Quetta, Pakistan
| | - Adeel Ahmad
- Department of Medicine, Mayo Hospital, Lahore, Pakistan
| | - Betul Baykan
- 1] Department of Neurology, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey. [2] Epilepsy Center (EPIMER), Istanbul University, Istanbul, Turkey
| | - Edith Said
- 1] Department of Anatomy and Cell Biology, University of Malta, Msida, Malta. [2] Section of Medical Genetics, Mater dei Hospital, Msida, Malta
| | - Meral Topcu
- Division of Pediatric Neurology, Department of Pediatrics, Hacettepe University Faculty of Medicine, Ankara, Turkey
| | - Patrizia Riguzzi
- Neurology Unit, IRCCS Institute of Neurological Sciences of Bologna, Bellaria Hospital, Bologna, Italy
| | - Mary D King
- 1] Department of Neurology, Temple Street Children's University Hospital, Dublin, Ireland. [2] Academic Centre on Rare Diseases, School of Medicine and Medical Science, University College Dublin, Dublin, Ireland
| | - Cigdem Ozkara
- Department of Neurology, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey
| | - Danielle M Andrade
- Division of Neurology, Department of Medicine, University of Toronto, Toronto Western Hospital, Krembil Neurosciences Program, Toronto, Ontario, Canada
| | - Bernt A Engelsen
- 1] Department of Clinical Medicine, University of Bergen, Bergen, Norway. [2] Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | | | - Matthias Lindenau
- Department of Neurology and Epileptology, Epilepsy Center Hamburg-Alsterdorf, Hamburg, Germany
| | - Ebba Lohmann
- 1] Department of Neurology and Epileptology, Epilepsy Center Hamburg-Alsterdorf, Hamburg, Germany. [2] Department of Neurodegenerative Diseases, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany. [3] German Center for Neurodegenerative Diseases (DZNE), Tübingen, Germany
| | - Veronica Saletti
- Developmental Neurology Unit, C. Besta Foundation Neurological Institute, IRCCS, Milan, Italy
| | - João Massano
- 1] Department of Neurology, Centro Hospitalar São João, Porto, Portugal. [2] Department of Clinical Neurosciences and Mental Health, Faculty of Medicine, University of Porto, Porto, Portugal
| | - Michael Privitera
- Epilepsy Center, University of Cincinnati Neuroscience Institute, Cincinnati, Ohio, USA
| | - Alberto J Espay
- Gardner Center for Parkinson Disease and Movement Disorders, University of Cincinnati, Cincinnati, Ohio, USA
| | | | - Michael Duchowny
- 1] Brain Institute, Miami Children's Hospital, Miami, Florida, USA. [2] Department of Neurology, University of Miami Miller School of Medicine, Miami, Florida, USA
| | - Rikke S Møller
- 1] Danish Epilepsy Centre, Dianalund, Denmark. [2] Institute of Regional Health Services Research, University of Southern Denmark, Odense, Denmark
| | - Rachel Straussberg
- 1] Neurogenetic Clinic, Child Neurology Institute, Schneider Children's Medical Center of Israel, Petah Tiqvah, Israel. [2] Sackler School of Medicine, Tel-Aviv University, Ramat Aviv, Israel
| | - Zaid Afawi
- 1] Sackler School of Medicine, Tel-Aviv University, Ramat Aviv, Israel. [2] Zlotowski Center for Neuroscience, Ben-Gurion University, Beer-Sheva, Israel
| | - Bruria Ben-Zeev
- 1] Sackler School of Medicine, Tel-Aviv University, Ramat Aviv, Israel. [2] Pediatric Neurology Unit, Edmond and Lilly Safra Children's Hospital, Sheba Medical Center, Ramat-Gan, Israel
| | - Kaitlin E Samocha
- 1] Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA. [2] Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, Massachusetts, USA. [3] Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, Massachusetts, USA. [4] Program in Genetics and Genomics, Biological and Biomedical Sciences, Harvard Medical School, Boston, Massachusetts, USA
| | - Mark J Daly
- 1] Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA. [2] Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, Massachusetts, USA. [3] Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, Massachusetts, USA. [4] Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, Massachusetts, USA
| | - Steven Petrou
- 1] Florey Institute of Neuroscience and Mental Health, University of Melbourne, Melbourne, Victoria, Australia. [2] Centre for Neural Engineering, University of Melbourne, Melbourne, Victoria, Australia
| | - Holger Lerche
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, Tübingen, Germany
| | - Aarno Palotie
- 1] Institute for Molecular Medicine Finland, University of Helsinki, Helsinki, Finland. [2] Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, USA. [3] Program in Medical and Population Genetics, Broad Institute of Harvard and MIT, Cambridge, Massachusetts, USA. [4] Stanley Center for Psychiatric Research, Broad Institute of Harvard and MIT, Cambridge, Massachusetts, USA. [5] Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK. [6] Psychiatric and Neurodevelopmental Genetics Unit, Department of Psychiatry, Massachusetts General Hospital, Boston, Massachusetts, USA. [7] Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Anna-Elina Lehesjoki
- 1] Folkhälsan Institute of Genetics, Helsinki, Finland. [2] Neuroscience Center, University of Helsinki, Helsinki, Finland. [3] Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
| |
Collapse
|
16
|
Sialic acids attached to N- and O-glycans within the Nav1.4 D1S5-S6 linker contribute to channel gating. Biochim Biophys Acta Gen Subj 2014; 1850:307-17. [PMID: 25450184 DOI: 10.1016/j.bbagen.2014.10.027] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/09/2014] [Accepted: 10/23/2014] [Indexed: 01/02/2023]
Abstract
BACKGROUND Voltage-gated Na+ channels (Nav) are responsible for the initiation and conduction of neuronal and muscle action potentials. Nav gating can be altered by sialic acids attached to channel N-glycans, typically through isoform-specific electrostatic mechanisms. METHODS Using two sets of Chinese Hamster Ovary cell lines with varying abilities to glycosylate glycoproteins, we show for the first time that sialic acids attached to O-glycans and N-glycans within the Nav1.4 D1S5-S6 linker modulate Nav gating. RESULTS All measured steady-state and kinetic parameters were shifted to more depolarized potentials under conditions of essentially no sialylation. When sialylation of only N-glycans or of only O-glycans was prevented, the observed voltage-dependent parameter values were intermediate between those observed under full versus no sialylation. Immunoblot gel shift analyses support the biophysical data. CONCLUSIONS The data indicate that sialic acids attached to both N- and O-glycans residing within the Nav1.4 D1S5-S6 linker modulate channel gating through electrostatic mechanisms, with the relative contribution of sialic acids attached to N- versus O-glycans on channel gating being similar. GENERAL SIGNIFICANCE Protein N- and O-glycosylation can modulate ion channel gating simultaneously. These data also suggest that environmental, metabolic, and/or congenital changes in glycosylation that impact sugar substrate levels, could lead, potentially, to changes in Nav sialylation and gating that would modulate AP waveforms and conduction.
Collapse
|
17
|
Baycin-Hizal D, Gottschalk A, Jacobson E, Mai S, Wolozny D, Zhang H, Krag SS, Betenbaugh MJ. Physiologic and pathophysiologic consequences of altered sialylation and glycosylation on ion channel function. Biochem Biophys Res Commun 2014; 453:243-53. [PMID: 24971539 PMCID: PMC4544737 DOI: 10.1016/j.bbrc.2014.06.067] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Accepted: 06/13/2014] [Indexed: 01/01/2023]
Abstract
Voltage-gated ion channels are transmembrane proteins that regulate electrical excitability in cells and are essential components of the electrically active tissues of nerves, muscle and the heart. Potassium channels are one of the largest subfamilies of voltage sensitive channels and are among the most-studied of the voltage-gated ion channels. Voltage-gated channels can be glycosylated and changes in the glycosylation pattern can affect ion channel function, leading to neurological and neuromuscular disorders and congenital disorders of glycosylation (CDG). Alterations in glycosylation can also be acquired and appear to play a role in development and aging. Recent studies have focused on the impact of glycosylation and sialylation on ion channels, particularly for voltage-gated potassium and sodium channels. The terminal step of sialylation often affects channel activation and inactivation kinetics. The presence of sialic acids on O or N-glycans can alter the gating mechanism and cause conformational changes in the voltage-sensing domains due to sialic acid's negative charges. This manuscript will provide an overview of sialic acids, potassium and sodium channel function, and the impact of sialylation on channel activation and deactivation.
Collapse
Affiliation(s)
- Deniz Baycin-Hizal
- Chemical and Biomolecular Engineering, Johns Hopkins University, United States.
| | - Allan Gottschalk
- Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, United States
| | - Elena Jacobson
- Chemical and Biomolecular Engineering, Johns Hopkins University, United States
| | - Sunny Mai
- Chemical and Biomolecular Engineering, Johns Hopkins University, United States
| | - Daniel Wolozny
- Chemical and Biomolecular Engineering, Johns Hopkins University, United States
| | - Hui Zhang
- Pathology, Johns Hopkins University, United States
| | - Sharon S Krag
- Biochemistry and Molecular Biology, Johns Hopkins Bloomberg School of Public Health, United States
| | | |
Collapse
|
18
|
|
19
|
Nowycky MC, Wu G, Ledeen RW. Glycobiology of ion transport in the nervous system. ADVANCES IN NEUROBIOLOGY 2014; 9:321-42. [PMID: 25151386 DOI: 10.1007/978-1-4939-1154-7_15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The nervous system is richly endowed with large transmembrane proteins that mediate ion transport, including gated ion channels as well as energy-consuming pumps and transporters. Transport proteins undergo N-linked glycosylation which can affect expression, location, stability, and function. The N-linked glycans of ion channels are large, contributing between 5 and 50 % of their molecular weight. Many contain a high density of negatively charged sialic acid residues which modulate voltage-dependent gating of ion channels. Changes in the size and chemical composition of glycans are responsible for developmental and cell-specific variability in the biophysical and functional properties of many ion channels. Glycolipids, principally gangliosides, exert considerable influence on some forms of ion transport, either through direct association with ion transport proteins or indirectly through association with proteins that activate transport through appropriate signaling. Examples of both pumps and ion channels have been revealed which depend on ganglioside regulation. While some of these processes are localized in the plasma membrane, ganglioside-regulated ion transport can also occur at various loci within the cell including the nucleus. This chapter will describe ion channel and ion pump structures with a focus on the functional effects of glycosylation on ion channel availability and function, and effects of alterations in glycosylation on nervous system function. It will also summarize highlights of the research on glycolipid/ganglioside-mediated regulation of ion transport.
Collapse
Affiliation(s)
- Martha C Nowycky
- Department of Pharmacology and Physiology, RBHS, New Jersey Medical School, The State University of New Jersey, 185 South Orange Ave., Newark, NJ, 07103, USA,
| | | | | |
Collapse
|
20
|
Bae SH, Kim DH, Shin SK, Choi JS, Park KS. Src regulates membrane trafficking of the Kv3.1b channel. FEBS Lett 2013; 588:86-91. [PMID: 24291260 DOI: 10.1016/j.febslet.2013.11.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2013] [Revised: 11/01/2013] [Accepted: 11/05/2013] [Indexed: 10/26/2022]
Abstract
The Kv3.1 channel plays a crucial role in regulating the high-frequency firing properties of neurons. Here, we determined whether Src regulates the subcellular distributions of the Kv3.1b channel. Co-expression of active Src induced a dramatic redistribution of Kv3.1b to the endoplasmic reticulum. Furthermore, co-expression of the Kv3.1b channel with active Src induced a remarkable decrease in the pool of Kv3.1b at the cell surface. Moreover, the co-expression of active Src results in a significant decrease in the peak current densities of the Kv3.1b channel, and a substantial alteration in the voltage dependence of its steady-state inactivation. Taken together, these results indicate that Src kinase may play an important role in regulating membrane trafficking of Kv3.1b channels.
Collapse
Affiliation(s)
- Seong Han Bae
- Department of Physiology, Kyung Hee University School of Medicine, Seoul 130-701, South Korea
| | - Dong Hyun Kim
- College of Pharmacy, Catholic University of Korea, Bucheon 420-743, Gyeonggi-Do, South Korea
| | - Seok Kyo Shin
- Department of Physiology, Kyung Hee University School of Medicine, Seoul 130-701, South Korea
| | - Jin Sung Choi
- College of Pharmacy, Catholic University of Korea, Bucheon 420-743, Gyeonggi-Do, South Korea
| | - Kang-Sik Park
- Department of Physiology, Kyung Hee University School of Medicine, Seoul 130-701, South Korea; Biomedical Science Institute, Kyung Hee University School of Medicine, Seoul 130-701, South Korea.
| |
Collapse
|
21
|
Abstract
Control and modulation of electrical signaling is vital to normal physiology, particularly in neurons, cardiac myocytes, and skeletal muscle. The orchestrated activities of variable sets of ion channels and transporters, including voltage-gated ion channels (VGICs), are responsible for initiation, conduction, and termination of the action potential (AP) in excitable cells. Slight changes in VGIC activity can lead to severe pathologies including arrhythmias, epilepsies, and paralyses, while normal excitability depends on the precise tuning of the AP waveform. VGICs are heavily posttranslationally modified, with upward of 30% of the mature channel mass consisting of N- and O-glycans. These glycans are terminated typically by negatively charged sialic acid residues that modulate voltage-dependent channel gating directly. The data indicate that sialic acids alter VGIC activity in isoform-specific manners, dependent in part, on the number/location of channel sialic acids attached to the pore-forming alpha and/or auxiliary subunits that often act through saturating electrostatic mechanisms. Additionally, cell-specific regulation of sialylation can affect VGIC gating distinctly. Thus, channel sialylation is likely regulated through two mechanisms that together contribute to a dynamic spectrum of possible gating motifs: a subunit-specific mechanism and regulated (aberrant) changes in the ability of the cell to glycosylate. Recent studies showed that neuronal and cardiac excitability is modulated through regulated changes in voltage-gated Na(+) channel sialylation, suggesting that both mechanisms of differential VGIC sialylation contribute to electrical signaling in the brain and heart. Together, the data provide insight into an important and novel paradigm involved in the control and modulation of electrical signaling.
Collapse
Affiliation(s)
- Andrew R Ednie
- Programs in Cardiovascular Research and Neuroscience, Department of Molecular Pharmacology & Physiology, College of Medicine, University of South Florida, Tampa, Florida, USA
| | | |
Collapse
|
22
|
Torrente D, Avila MF, Cabezas R, Morales L, Gonzalez J, Samudio I, Barreto GE. Paracrine factors of human mesenchymal stem cells increase wound closure and reduce reactive oxygen species production in a traumatic brain injury in vitro model. Hum Exp Toxicol 2013; 33:673-84. [PMID: 24178889 DOI: 10.1177/0960327113509659] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Traumatic brain injury (TBI) consists of a primary and a secondary insult characterized by a biochemical cascade that plays a crucial role in cell death in the brain. Despite the major improvements in the acute care of head injury victims, no effective strategies exist for preventing the secondary injury cascade. This lack of success might be due to that most treatments are aimed at targeting neuronal population, even if studies show that astrocytes play a key role after a brain damage. In this work, we propose a new model of in vitro traumatic brain-like injury and use paracrine factors released by human mesenchymal stem cells (hMSCs) as a neuroprotective strategy. Our results demonstrate that hMSC-conditioned medium increased wound closure and proliferation at 12 h and reduced superoxide production to control conditions. This was accompanied by changes in cell morphology and polarity index, as both parameters reflect the ability of cells to migrate toward the wound. These findings indicate that hMSC is an important regulator of oxidative stress production, enhances cells migration, and shall be considered as a useful neuroprotective approach for brain recovery following injury.
Collapse
Affiliation(s)
- D Torrente
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá DC, Colombia
| | - M F Avila
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá DC, Colombia
| | - R Cabezas
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá DC, Colombia
| | - L Morales
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá DC, Colombia
| | - J Gonzalez
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá DC, Colombia
| | - I Samudio
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá DC, Colombia
| | - G E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá DC, Colombia
| |
Collapse
|
23
|
Hall MK, Weidner DA, Bernetski CJ, Schwalbe RA. N-Linked glycan site occupancy impacts the distribution of a potassium channel in the cell body and outgrowths of neuronal-derived cells. Biochim Biophys Acta Gen Subj 2013; 1840:595-604. [PMID: 24161696 DOI: 10.1016/j.bbagen.2013.10.025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 09/30/2013] [Accepted: 10/16/2013] [Indexed: 10/26/2022]
Abstract
BACKGROUND Vacancy of occupied N-glycosylation sites of glycoproteins is quite disruptive to a multicellular organism, as underlined by congenital disorders of glycosylation. Since a neuronal component is typically associated with this disease, we evaluated the impact of N-glycosylation processing of a neuronal voltage gated potassium channel, Kv3.1b, expressed in a neuronal-derived cell line, B35 neuroblastoma cells. METHODS Total internal reflection fluorescence and differential interference contrast microscopy measurements of live B35 cells expressing wild type and glycosylation mutant Kv3.1b proteins were used to evaluate the distribution of the various forms of the Kv3.1b protein in the cell body and outgrowths. Cell adhesion assays were also employed. RESULTS Microscopy images revealed that occupancy of both N-glycosylation sites of Kv3.1b had relatively similar amounts of Kv3.1b in the outgrowth and cell body while vacancy of one or both sites led to increased accumulation of Kv3.1b in the cell body. Further both the fully glycosylated and partially glycosylated N229Q Kv3.1b proteins formed higher density particles in outgrowths compared to cell body. Cellular assays demonstrated that the distinct spatial arrangements altered cell adhesion properties. CONCLUSIONS Our findings provide direct evidence that occupancy of the N-glycosylation sites of Kv3.1b contributes significantly to its lateral heterogeneity in membranes of neuronal-derived cells, and in turn alters cellular properties. GENERAL SIGNIFICANCE Our study demonstrates that N-glycans of Kv3.1b contain information regarding the association, clustering, and distribution of Kv3.1b in the cell membrane, and furthermore that decreased occupancy caused by congenital disorders of glycosylation may alter the biological activity of Kv3.1b.
Collapse
Affiliation(s)
- M K Hall
- Department of Biochemistry and Molecular Biology, Brody School of Medicine at East Carolina University, Greenville, NC 27834, USA
| | | | | | | |
Collapse
|
24
|
Hall MK, Weidner DA, Chen JM, Bernetski CJ, Schwalbe RA. Glycan structures contain information for the spatial arrangement of glycoproteins in the plasma membrane. PLoS One 2013; 8:e75013. [PMID: 24040379 PMCID: PMC3765438 DOI: 10.1371/journal.pone.0075013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Accepted: 08/10/2013] [Indexed: 01/27/2023] Open
Abstract
Glycoconjugates at the cell surface are crucial for cells to communicate with each other and the extracellular microenvironment. While it is generally accepted that glycans are vectorial biopolymers, their information content is unclear. This report provides evidence that distinct N-glycan structures influence the spatial arrangement of two integral membrane glycoproteins, Kv3.1 and E-cadherin, at the adherent membrane which in turn alter cellular properties. Distinct N-glycan structures were generated by heterologous expression of these glycoproteins in parental and glycosylation mutant Chinese hamster ovary cell lines. Unlike the N-linked glycans, the O-linked glycans of the mutant cell lines are similar to those of the parental cell line. Western and lectin blots of total membranes and GFP immunopurified samples, combined with glycosidase digestion reactions, were employed to verify the glycoproteins had predominantly complex, oligomannose, and bisecting type N-glycans from Pro-5, Lec1, and Lec10B cell lines, respectively. Based on total internal reflection fluorescence and differential interference contrast microscopy techniques, and cellular assays of live parental and glycosylation mutant CHO cells, we propose that glycoproteins with complex, oligomannose or bisecting type N-glycans relay information for localization of glycoproteins to various regions of the plasma membrane in both a glycan-specific and protein-specific manner, and furthermore cell-cell interactions are required for deciphering much of this information. These distinct spatial arrangements also impact cell adhesion and migration. Our findings provide direct evidence that N-glycan structures of glycoproteins contribute significantly to the information content of cells.
Collapse
Affiliation(s)
- M. Kristen Hall
- Department of Biochemistry and Molecular Biology, Brody School of Medicine at East Carolina University, Greenville, North Carolina, United States of America
| | - Douglas A. Weidner
- Department of Microbiology and Immunology, Brody School of Medicine at East Carolina University, Greenville, North Carolina, United States of America
| | - Jian ming Chen
- Department of Biochemistry and Molecular Biology, Brody School of Medicine at East Carolina University, Greenville, North Carolina, United States of America
| | - Christopher J. Bernetski
- Department of Biochemistry and Molecular Biology, Brody School of Medicine at East Carolina University, Greenville, North Carolina, United States of America
| | - Ruth A. Schwalbe
- Department of Biochemistry and Molecular Biology, Brody School of Medicine at East Carolina University, Greenville, North Carolina, United States of America
- * E-mail:
| |
Collapse
|
25
|
Rinflerch AR, Burgos VL, Ielpi M, Quintana MO, Hidalgo AM, Loresi M, Argibay PF. Inhibition of brain ST8SiaIII sialyltransferase leads to impairment of procedural memory in mice. Neurochem Int 2013; 63:397-404. [PMID: 23932970 DOI: 10.1016/j.neuint.2013.07.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 07/27/2013] [Accepted: 07/30/2013] [Indexed: 01/04/2023]
Abstract
Several glycoproteins in mammalian brains contain α2,8-linked disialic acid residues. We previously showed a constant expression of disialic acid (DiSia) in the hippocampus, olfactory bulb and cortex, and a gradual decrease of expression in the cerebellum from neonatal to senile mice. Previous publications indicate that neurite extension of neuroblastoma-derived Neuro2A cells is inhibited in the presence of DiSia antibody. Based on this, we treated Neuro2A cell cultures with RNA interference for ST8SiaIII mRNA, the enzyme responsible for DiSia formation. We observed that neurite extension was inhibited by this treatment. Taking this evidence into consideration and the relationship of the cerebellum with learning and memory, we studied the role of DiSia expression in a learning task. Through delivery of pST8SiaIII into the brains of C57BL/6 neonatal mice, we inhibited the expression of ST8SiaIII. ST8SiaIII mRNA and protein expressions were analyzed by real-time PCR and western blot, respectively. In this work, we showed that pST8SiaIII-treated mice presented a significantly reduced level of ST8SiaIII mRNA in the cerebellum (p<0.01) in comparison to control mice at 8 days after treatment. It is also noted that these levels returned to baseline values in the adulthood. Then, we evaluated behavioural performance in the T-Maze, a learning task that estimates procedural memory. At all ages, pST8SiaIII-treated mice showed a lower performance in the test session, being most evident at older ages (p<0.001). Taken all together, we conclude that gene expression of ST8SiaIII is necessary for some cognitive tasks at early postnatal ages, since reduced levels impaired procedural memory in adult mice.
Collapse
Affiliation(s)
- Adriana R Rinflerch
- Instituto de Ciencias Básicas y Medicina Experimental - Hospital Italiano de Buenos Aires, Potosí 4240 8th floor, C1199ACL, Ciudad Autónoma de Buenos Aires, Argentina
| | | | | | | | | | | | | |
Collapse
|
26
|
Weng TY, Chiu WT, Liu HS, Cheng HC, Shen MR, Mount DB, Chou CY. Glycosylation regulates the function and membrane localization of KCC4. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:1133-46. [DOI: 10.1016/j.bbamcr.2013.01.018] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2012] [Revised: 12/28/2012] [Accepted: 01/15/2013] [Indexed: 10/27/2022]
|
27
|
Mant A, Williams S, Roncoroni L, Lowry E, Johnson D, O'Kelly I. N-glycosylation-dependent control of functional expression of background potassium channels K2P3.1 and K2P9.1. J Biol Chem 2012; 288:3251-64. [PMID: 23250752 DOI: 10.1074/jbc.m112.405167] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Two-pore domain potassium (K(2P)) channels play fundamental roles in cellular processes by enabling a constitutive leak of potassium from cells in which they are expressed, thus influencing cellular membrane potential and activity. Hence, regulation of these channels is of critical importance to cellular function. A key regulatory mechanism of K(2P) channels is the control of their cell surface expression. Membrane protein delivery to and retrieval from the cell surface is controlled by their passage through the secretory and endocytic pathways, and post-translational modifications regulate their progression through these pathways. All but one of the K(2P) channels possess consensus N-linked glycosylation sites, and here we demonstrate that the conserved putative N-glycosylation site in K(2P)3.1 and K(2P)9.1 is a glycan acceptor site. Patch clamp analysis revealed that disruption of channel glycosylation reduced K(2P)3.1 current, and flow cytometry was instrumental in attributing this to a decreased number of channels on the cell surface. Similar findings were observed when cells were cultured in reduced glucose concentrations. Disruption of N-linked glycosylation has less of an effect on K(2P)9.1, with a small reduction in number of channels on the surface observed, but no functional implications detected. Because nonglycosylated channels appear to pass through the secretory pathway in a manner comparable with glycosylated channels, the evidence presented here suggests that the decreased number of nonglycosylated K(2P)3.1 channels on the cell surface may be due to their decreased stability.
Collapse
Affiliation(s)
- Alexandra Mant
- Human Development and Health, Centre for Human Development, Stem Cells and Regeneration, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, United Kingdom
| | | | | | | | | | | |
Collapse
|
28
|
Mining the virgin land of neurotoxicology: a novel paradigm of neurotoxic peptides action on glycosylated voltage-gated sodium channels. J Toxicol 2012; 2012:843787. [PMID: 22829817 PMCID: PMC3399347 DOI: 10.1155/2012/843787] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Revised: 04/17/2012] [Accepted: 05/24/2012] [Indexed: 12/30/2022] Open
Abstract
Voltage-gated sodium channels (VGSCs) are important membrane protein carrying on the molecular basis for action potentials (AP) in neuronal firings. Even though the structure-function studies were the most pursued spots, the posttranslation modification processes, such as glycosylation, phosphorylation, and alternative splicing associating with channel functions captured less eyesights. The accumulative research suggested an interaction between the sialic acids chains and ion-permeable pores, giving rise to subtle but significant impacts on channel gating. Sodium channel-specific neurotoxic toxins, a family of long-chain polypeptides originated from venomous animals, are found to potentially share the binding sites adjacent to glycosylated region on VGSCs. Thus, an interaction between toxin and glycosylated VGSC might hopefully join the campaign to approach the role of glycosylation in modulating VGSCs-involved neuronal network activity. This paper will cover the state-of-the-art advances of researches on glycosylation-mediated VGSCs function and the possible underlying mechanisms of interactions between toxin and glycosylated VGSCs, which may therefore, fulfill the knowledge in identifying the pharmacological targets and therapeutic values of VGSCs.
Collapse
|
29
|
Wang L, Aryal UK, Dai Z, Mason AC, Monroe ME, Tian ZX, Zhou JY, Su D, Weitz KK, Liu T, Camp DG, Smith RD, Baker SE, Qian WJ. Mapping N-linked glycosylation sites in the secretome and whole cells of Aspergillus niger using hydrazide chemistry and mass spectrometry. J Proteome Res 2011; 11:143-56. [PMID: 22136231 DOI: 10.1021/pr200916k] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Protein glycosylation (e.g., N-linked glycosylation) is known to play an essential role in both cellular functions and secretory pathways; however, our knowledge of in vivo N-glycosylated sites is very limited for the majority of fungal organisms including Aspergillus niger. Herein, we present the first extensive mapping of N-glycosylated sites in A. niger by applying an optimized solid phase glycopeptide enrichment protocol using hydrazide-modified magnetic beads. The enrichment protocol was initially optimized using both mouse blood plasma and A. niger secretome samples, and it was demonstrated that the protein-level enrichment protocol offered superior performance over the peptide-level protocol. The optimized protocol was then applied to profile N-glycosylated sites from both the secretome and whole cell lysates of A. niger. A total of 847 N-glycosylated sites from 330 N-glycoproteins (156 proteins from the secretome and 279 proteins from whole cells) were confidently identified by LC-MS/MS. The identified N-glycoproteins in the whole cell lysate were primarily localized in the plasma membrane, endoplasmic reticulum, Golgi apparatus, lysosome, and storage vacuoles, supporting the important role of N-glycosylation in the secretory pathways. In addition, these glycoproteins are involved in many biological processes including gene regulation, signal transduction, protein folding and assembly, protein modification, and carbohydrate metabolism. The extensive coverage of N-glycosylated sites and the observation of partial glycan occupancy on specific sites in a number of enzymes provide important initial information for functional studies of N-linked glycosylation and their biotechnological applications in A. niger.
Collapse
Affiliation(s)
- Lu Wang
- Biological Science Division, Pacific Northwest National Laboratory, Richland, Washington 99352, United States
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Biochemical engineering of the N-acyl side chain of sialic acids alters the kinetics of a glycosylated potassium channel Kv3.1. FEBS Lett 2011; 585:3322-7. [PMID: 21945320 DOI: 10.1016/j.febslet.2011.09.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2011] [Revised: 09/13/2011] [Accepted: 09/14/2011] [Indexed: 11/23/2022]
Abstract
The sialic acid of complex N-glycans can be biochemically engineered by substituting the physiological precursor N-acetylmannosamine with non-natural N-acylmannosamines. The Kv3.1 glycoprotein, a neuronal voltage-gated potassium channel, contains sialic acid. Western blots of the Kv3.1 glycoprotein isolated from transfected B35 neuroblastoma cells incubated with N-acylmannosamines verified sialylated N-glycans attached to the Kv3.1 glycoprotein. Outward ionic currents of Kv3.1 transfected B35 cells treated with N-pentanoylmannosamine or N-propanoylmannosamine had slower activation and inactivation rates than those of untreated cells. Therefore, the N-acyl side chain of sialic acid is intimately connected with the activation and inactivation rates of this glycosylated potassium channel.
Collapse
|