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Chandrasekaran R, Mathieu C, Sheth R, Cheng AP, Fong D, McCormack R, El-Gabalawy H, Alishetty S, Paige M, Hoemann CD. UDP-glucose dehydrogenase (UGDH) activity is suppressed by peroxide and promoted by PDGF in fibroblast-like synoviocytes: Evidence of a redox control mechanism. PLoS One 2022; 17:e0274420. [PMID: 36107941 PMCID: PMC9477357 DOI: 10.1371/journal.pone.0274420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Accepted: 08/29/2022] [Indexed: 11/18/2022] Open
Abstract
UDP-glucose dehydrogenase (UGDH) generates essential precursors of hyaluronic acid (HA) synthesis, however mechanisms regulating its activity are unclear. We used enzyme histostaining and quantitative image analysis to test whether cytokines that stimulate HA synthesis upregulate UGDH activity. Fibroblast-like synoviocytes (FLS, from N = 6 human donors with knee pain) were cultured, freeze-thawed, and incubated for 1 hour with UDP-glucose, NAD+ and nitroblue tetrazolium (NBT) which allows UGDH to generate NADH, and NADH to reduce NBT to a blue stain. Compared to serum-free medium, FLS treated with PDGF showed 3-fold higher UGDH activity and 6-fold higher HA release, but IL-1beta/TGF-beta1 induced 27-fold higher HA release without enhancing UGDH activity. In selected proliferating cells, UGDH activity was lost in the cytosol, but preserved in the nucleus. Cell-free assays led us to discover that diaphorase, a cytosolic enzyme, or glutathione reductase, a nuclear enzyme, was necessary and sufficient for NADH to reduce NBT to a blue formazan dye in a 1-hour timeframe. Primary synovial fibroblasts and transformed A549 fibroblasts showed constitutive diaphorase/GR staining activity that varied according to supplied NADH levels, with relatively stronger UGDH and diaphorase activity in A549 cells. Unilateral knee injury in New Zealand White rabbits (N = 3) stimulated a coordinated increase in synovial membrane UGDH and diaphorase activity, but higher synovial fluid HA in only 2 out of 3 injured joints. UGDH activity (but not diaphorase) was abolished by N-ethyl maleimide, and inhibited by peroxide or UDP-xylose. Our results do not support the hypothesis that UGDH is a rate-liming enzyme for HA synthesis under catabolic inflammatory conditions that can oxidize and inactivate the UGDH active site cysteine. Our novel data suggest a model where UGDH activity is controlled by a redox switch, where intracellular peroxide inactivates, and high glutathione and diaphorase promote UGDH activity by maintaining the active site cysteine in a reduced state, and by recycling NAD+ from NADH.
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Affiliation(s)
- Ramya Chandrasekaran
- Department of Bioengineering, George Mason University, Manassas, Virginia, United States of America
| | - Colleen Mathieu
- Institute of Biomedical Engineering, Polytechnique Montréal, Montréal, QC, Canada
- Department of Chemical Engineering, Polytechnique Montréal, Montréal, QC, Canada
| | - Rishi Sheth
- Department of Bioengineering, George Mason University, Manassas, Virginia, United States of America
| | - Alexandre P. Cheng
- Department of Chemical Engineering, Polytechnique Montréal, Montréal, QC, Canada
| | - David Fong
- Institute of Biomedical Engineering, Polytechnique Montréal, Montréal, QC, Canada
| | - Robert McCormack
- Department of Orthopedic Surgery, University of British Columbia, Vancouver, BC, Canada
| | - Hani El-Gabalawy
- Department of Medicine and Immunology, University of Manitoba, Winnipeg, MB, Canada
| | - Suman Alishetty
- Department of Bioengineering, George Mason University, Manassas, Virginia, United States of America
| | - Mikell Paige
- Department of Chemistry & Biochemistry, George Mason University, Manassas, Virginia, United States of America
| | - Caroline D. Hoemann
- Department of Bioengineering, George Mason University, Manassas, Virginia, United States of America
- Institute of Biomedical Engineering, Polytechnique Montréal, Montréal, QC, Canada
- Department of Chemical Engineering, Polytechnique Montréal, Montréal, QC, Canada
- * E-mail:
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Gao Q, Cheng B, Chen C, Lei C, Lin X, Nie D, Li J, Huang L, Li X, Wang K, Huang A, Tang N. Dysregulated glucuronic acid metabolism exacerbates hepatocellular carcinoma progression and metastasis through the TGFβ signalling pathway. Clin Transl Med 2022; 12:e995. [PMID: 35979621 PMCID: PMC9386326 DOI: 10.1002/ctm2.995] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 07/05/2022] [Accepted: 07/11/2022] [Indexed: 11/08/2022] Open
Abstract
BACKGROUND Glucuronic acid metabolism participates in cellular detoxification, extracellular matrix remodeling and cell adhesion and migration. Here, we aimed to explore the crosstalk between dysregulated glucuronic acid metabolism and crucial metastatic signalling in glutathione S-transferase zeta 1 (GSTZ1)-deficient hepatocellular carcinoma (HCC). METHODS Transwell, HCC xenograft and Gstz1-/- mouse models were used to examine the role of GSTZ1 in HCC metastasis. Non-targeted and targeted metabolomics and global transcriptomic analyses were performed to screen significantly altered metabolic and signalling pathways in GSTZ1 overexpressing hepatoma cells. Further, RNA-binding protein immunoprecipitation, Biotin-RNA pull-down, mRNA decay assays and luciferase reporter assays were used to explore the interaction between RNA and RNA-binding proteins. RESULTS GSTZ1 was universally silenced in both human and murine HCC cells, and its deficiency contributed to HCC metastasis in vitro and in vivo. UDP-glucose 6-dehydrogenase (UGDH)-mediated UDP-glucuronic acid (UDP-GlcUA) accumulation promoted hepatoma cell migration upon GSTZ1 loss. UDP-GlcUA stabilized TGFβR1 mRNA by enhancing its binding to polypyrimidine tract binding protein 3, contributing to the activation of TGFβ/Smad signalling. UGDH or TGFβR1 blockade impaired HCC metastasis. In addition, UGDH up-regulation and UDP-GlcUA accumulation correlated with increased metastatic potential and decreased patient survival in GSTZ1-deficient HCC. CONCLUSIONS GSTZ1 deficiency and subsequent up-regulation of the glucuronic acid metabolic pathway promotes HCC metastasis by increasing the stability of TGFβR1 mRNA and activating TGFβ/Smad signalling. UGDH and a key metabolite, UDP-GlcUA, may serve as prognostic markers. Targeting UGDH might be a promising strategy for HCC therapy.
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Affiliation(s)
- Qingzhu Gao
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Bin Cheng
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Chang Chen
- Institute of Life Sciences, Chongqing Medical University, Chongqing, China
| | - Chong Lei
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Xue Lin
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Dan Nie
- Department of Gastroenterology, Chongqing Hospital of Traditional Chinese Medicine, Chongqing, China
| | - Jingjing Li
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Luyi Huang
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Xiaosong Li
- Clinical Molecular Medicine Testing Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Kai Wang
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Ailong Huang
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
| | - Ni Tang
- Key Laboratory of Molecular Biology for Infectious Diseases (Ministry of Education), Institute for Viral Hepatitis, Department of Infectious Diseases, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, China
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Vitale DL, Caon I, Parnigoni A, Sevic I, Spinelli FM, Icardi A, Passi A, Vigetti D, Alaniz L. Initial Identification of UDP-Glucose Dehydrogenase as a Prognostic Marker in Breast Cancer Patients, Which Facilitates Epirubicin Resistance and Regulates Hyaluronan Synthesis in MDA-MB-231 Cells. Biomolecules 2021; 11:biom11020246. [PMID: 33572239 PMCID: PMC7914570 DOI: 10.3390/biom11020246] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 12/11/2022] Open
Abstract
UDP-glucose-dehydrogenase (UGDH) synthesizes UDP-glucuronic acid. It is involved in epirubicin detoxification and hyaluronan synthesis. This work aimed to evaluate the effect of UGDH knockdown on epirubicin response and hyaluronan metabolism in MDA-MB-231 breast cancer cells. Additionally, the aim was to determine UGDH as a possible prognosis marker in breast cancer. We studied UGDH expression in tumors and adjacent tissue from breast cancer patients. The prognostic value of UGDH was studied using a public Kaplan–Meier plotter. MDA-MB-231 cells were knocked-down for UGDH and treated with epirubicin. Epirubicin-accumulation and apoptosis were analyzed by flow cytometry. Hyaluronan-coated matrix and metabolism were determined. Autophagic-LC3-II was studied by Western blot and confocal microscopy. Epirubicin accumulation increased and apoptosis decreased during UGDH knockdown. Hyaluronan-coated matrix increased and a positive modulation of autophagy was detected. Higher levels of UGDH were correlated with worse prognosis in triple-negative breast cancer patients that received chemotherapy. High expression of UGDH was found in tumoral tissue from HER2--patients. However, UGDH knockdown contributes to epirubicin resistance, which might be associated with increases in the expression, deposition and catabolism of hyaluronan. The results obtained allowed us to propose UGDH as a new prognostic marker in breast cancer, positively associated with development of epirubicin resistance and modulation of extracellular matrix.
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Affiliation(s)
- Daiana L. Vitale
- Laboratorio de Microambiente Tumoral, Centro de Investigaciones Básicas y Aplicadas (CIBA), Universidad Nacional del Noroeste de la Provincia de Buenos Aires, Junín 6000, Argentina; (D.L.V.); (I.S.); (F.M.S.); (A.I.)
- Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires (CITNOBA), UNNOBA-UNSAdA-CONICET, Junín 6000, Argentina
| | - Ilaria Caon
- Dipartimento di Medicina e Chirurgia, Università degli Studio dell’Insubria, 21100 Varese, Italy; (I.C.); (A.P.); (A.P.)
| | - Arianna Parnigoni
- Dipartimento di Medicina e Chirurgia, Università degli Studio dell’Insubria, 21100 Varese, Italy; (I.C.); (A.P.); (A.P.)
| | - Ina Sevic
- Laboratorio de Microambiente Tumoral, Centro de Investigaciones Básicas y Aplicadas (CIBA), Universidad Nacional del Noroeste de la Provincia de Buenos Aires, Junín 6000, Argentina; (D.L.V.); (I.S.); (F.M.S.); (A.I.)
- Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires (CITNOBA), UNNOBA-UNSAdA-CONICET, Junín 6000, Argentina
| | - Fiorella M. Spinelli
- Laboratorio de Microambiente Tumoral, Centro de Investigaciones Básicas y Aplicadas (CIBA), Universidad Nacional del Noroeste de la Provincia de Buenos Aires, Junín 6000, Argentina; (D.L.V.); (I.S.); (F.M.S.); (A.I.)
- Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires (CITNOBA), UNNOBA-UNSAdA-CONICET, Junín 6000, Argentina
| | - Antonella Icardi
- Laboratorio de Microambiente Tumoral, Centro de Investigaciones Básicas y Aplicadas (CIBA), Universidad Nacional del Noroeste de la Provincia de Buenos Aires, Junín 6000, Argentina; (D.L.V.); (I.S.); (F.M.S.); (A.I.)
- Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires (CITNOBA), UNNOBA-UNSAdA-CONICET, Junín 6000, Argentina
| | - Alberto Passi
- Dipartimento di Medicina e Chirurgia, Università degli Studio dell’Insubria, 21100 Varese, Italy; (I.C.); (A.P.); (A.P.)
| | - Davide Vigetti
- Dipartimento di Medicina e Chirurgia, Università degli Studio dell’Insubria, 21100 Varese, Italy; (I.C.); (A.P.); (A.P.)
- Correspondence: (D.V.); (L.A.); Tel.: + 39-332-307170 (D.V.); +54-236-4-407750 (ext. 11625) (L.A.)
| | - Laura Alaniz
- Laboratorio de Microambiente Tumoral, Centro de Investigaciones Básicas y Aplicadas (CIBA), Universidad Nacional del Noroeste de la Provincia de Buenos Aires, Junín 6000, Argentina; (D.L.V.); (I.S.); (F.M.S.); (A.I.)
- Centro de Investigaciones y Transferencia del Noroeste de la Provincia de Buenos Aires (CITNOBA), UNNOBA-UNSAdA-CONICET, Junín 6000, Argentina
- Correspondence: (D.V.); (L.A.); Tel.: + 39-332-307170 (D.V.); +54-236-4-407750 (ext. 11625) (L.A.)
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Fernando R, Smith TJ. Slit2 Regulates Hyaluronan & Cytokine Synthesis in Fibrocytes: Potential Relevance to Thyroid-Associated Ophthalmopathy. J Clin Endocrinol Metab 2021; 106:e20-e33. [PMID: 32968816 PMCID: PMC7765649 DOI: 10.1210/clinem/dgaa684] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 09/18/2020] [Indexed: 02/06/2023]
Abstract
CONTEXT CD34+ fibrocytes have been implicated in development of thyroid-associated ophthalmopathy (TAO), a consequential autoimmune manifestation of Graves disease (GD). In TAO, CD34+ fibrocytes appear to masquerade as CD34+ orbital fibroblasts mixed with CD34- OF (collectively, GD-OF). Slit2, an axon guidance glycoprotein, is expressed by CD34- OF and attenuates GD-OF gene expression. Cardinal features of TAO include hyaluronan (HA) accumulation and cytokine-driven inflammation. OBJECTIVE Compare expression of HA synthase isoenzymes (HAS1-3), UDP-glucose dehydrogenase (UGDH), synthesis of HA, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in fibrocytes and GD-OF. Determine whether Slit2 alters gene expression patterns. DESIGN/SETTING/PARTICIPANTS Patients with TAO and healthy donors were recruited from an academic practice. MAIN OUTCOME MEASURES Real-time polymerase chain reaction, HA, IL-6, and TNF-α immunoassays. RESULTS HA synthesis and release from fibrocytes is substantially lower than in GD-OF. HAS1 expression dominates in fibrocytes while HAS2 in GD-OF. In contrast, HAS2 and UGDH expression dominate GD-OF and localize to CD34- OF. Recombinant human Slit2 (rhSlit2) substantially upregulates HA synthesis and HAS2 expression in fibrocytes but attenuates IL-6 and TNF-α production in these cells. In contrast, knocking down Slit2 in GD-OF reduces HA synthesis and HAS2 and UGDH expression while upregulating IL-6 and TNF-α. CONCLUSION The dramatic differences in HA, IL-6, and TNF-α production, and HAS and UGDH expression found in fibrocytes and GD-OF appear, at least in part, to be attributable to Slit2. These findings provide novel insight into the differences in gene expression exhibited by CD34+ fibrocytes and CD34+ OF and therefore reveal important aspects of disease pathogenesis.
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Affiliation(s)
- Roshini Fernando
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, Michigan
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan
| | - Terry J Smith
- Department of Ophthalmology and Visual Sciences, Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, Michigan
- Division of Metabolism, Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan
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Wang M, Xu Z, Ahmed RI, Wang Y, Hu R, Zhou G, Kong Y. Tubby-like Protein 2 regulates homogalacturonan biosynthesis in Arabidopsis seed coat mucilage. Plant Mol Biol 2019; 99:421-436. [PMID: 30707395 DOI: 10.1007/s11103-019-00827-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Accepted: 01/19/2019] [Indexed: 06/09/2023]
Abstract
A possible transcription factor TLP2 was identified to be involved in the regulation of HG biosynthesis in Arabidopsis seed mucilage. TLP2 can translocate into nucleus from plasma membrane by interacting with NF-YC3. The discovery of TLP2 gene function can further fulfill the regulatory network of pectin biosynthesis in Arabidopsis thaliana. Arabidopsis seed coat mucilage is an excellent model system to study the biosynthesis, function and regulation of pectin. Rhamnogalacturonan I (RG-I) and homogalacturonan (HG) are the major polysaccharides constituent of the Arabidopsis seed coat mucilage. Here, we identified a Tubby-like gene, Tubby-like protein 2 (TLP2), which was up-regulated in developing siliques when mucilage began to be produced. Ruthenium red (RR) staining of the seeds showed defective mucilage of tlp2-1 mutant after vigorous shaking compared to wild type (WT). Monosaccharide composition analysis revealed that the amount of total sugars and galacturonic acid (GalA) decreased significantly in the adherent mucilage (AM) of tlp2-1 mutant. Immunolabelling and dot immunoblotting analysis showed that unesterified HG decreased in the tlp2-1 mutant. Furthermore, TLP2 can translocate into nucleus by interacting with Nuclear Factor Y subunit C3 (NF-YC3) to function as a transcription factor. RNA-sequence and transactivation assays revealed that TLP2 could activate UDP-glucose 4-epimerase 1 (UGE1). In all, it is concluded that TLP2 could regulate the biosynthesis of HG possibly through the positive activation of UGE1.
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Affiliation(s)
- Meng Wang
- Key Laboratory for Tobacco Gene Resources, Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081, China
| | - Zongchang Xu
- Key Laboratory for Tobacco Gene Resources, Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
| | - Rana Imtiaz Ahmed
- Key Laboratory for Tobacco Gene Resources, Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China
- Graduate School of Chinese Academy of Agricultural Science, Beijing, 100081, China
| | - Yiping Wang
- Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
- Graduate School of University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ruibo Hu
- Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
| | - Gongke Zhou
- Qingdao Engineering Research Center of Biomass Resources and Environment, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao, 266101, China
| | - Yingzhen Kong
- Key Laboratory for Tobacco Gene Resources, Tobacco Research Institute, Chinese Academy of Agricultural Sciences, Qingdao, 266101, China.
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Abstract
Human UDP-glucose dehydrogenase (hUGDH) is regulated by an atypical allosteric mechanism in which the feedback inhibitor UDP-xylose (UDP-Xyl) competes with the substrate for the active site. Binding of UDP-Xyl triggers the T131-loop/α6 allosteric switch, which converts the hexameric structure of hUGDH into an inactive, horseshoe-shaped complex (EΩ). This allosteric transition buries residue A136 in the protein core to produce a subunit interface that favors the EΩ structure. Here we use a methionine substitution to prevent the burial of A136 and trap the T131-loop/α6 switch in the active conformation. We show that hUGDHA136M does not exhibit substrate cooperativity, which is strong evidence that the methionine substitution prevents the formation of the low-UDP-Glc-affinity EΩ state. In addition, the inhibitor affinity of hUGDHA136M is reduced 14-fold, which most likely represents the Ki for competitive inhibition in the absence of the allosteric transition to the higher-affinity EΩ state. hUGDH also displays a lag in progress curves, which is caused by a slow, substrate-induced isomerization that activates the enzyme. Stopped-flow analysis shows that hUGDHA136M does not exhibit hysteresis, which suggests that the T131-loop/α6 switch is the source of the slow isomerization. This interpretation is supported by the 2.05 Å resolution crystal structure of hUGDHA136M, which shows that the A136M substitution has stabilized the active conformation of the T131-loop/α6 allosteric switch. This work shows that the T131-loop/α6 allosteric switch couples allostery and hysteresis in hUGDH.
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Affiliation(s)
- Nathaniel R. Beattie
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Nicholas D. Keul
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Andrew M. Sidlo
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Zachary A. Wood
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602, USA
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Zimmer BM, Howell ME, Wei Q, Ma L, Romsdahl T, Loughman EG, Markham JE, Seravalli J, Barycki JJ, Simpson MA. Loss of exogenous androgen dependence by prostate tumor cells is associated with elevated glucuronidation potential. Horm Cancer 2016; 7:260-71. [PMID: 27307252 PMCID: PMC4955861 DOI: 10.1007/s12672-016-0268-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/11/2016] [Accepted: 06/08/2016] [Indexed: 12/20/2022]
Abstract
Prostate epithelial cells control the potency and availability of androgen hormones in part by inactivation and elimination. UDP-glucose dehydrogenase (UGDH) catalyzes the NAD(+)-dependent oxidation of UDP-glucose to UDP-glucuronate, an essential precursor for androgen inactivation by the prostate glucuronidation enzymes UGT2B15 and UGT2B17. UGDH expression is androgen stimulated, which increases the production of UDP-glucuronate and fuels UGT-catalyzed glucuronidation. In this study, we compared the glucuronidation potential and its impact on androgen-mediated gene expression in an isogenic LNCaP model for androgen-dependent versus castration-resistant prostate cancer. Despite significantly lower androgen-glucuronide output, LNCaP 81 castration-resistant tumor cells expressed higher levels of UGDH, UGT2B15, and UGT2B17. However, the magnitude of androgen-activated UGDH and prostate-specific antigen (PSA) expression, as well as the androgen receptor (AR)-dependent repression of UGT2B15 and UGT2B17, was blunted several-fold in these cells. Consistent with these results, the ligand-activated binding of AR to the PSA promoter and subsequent transcriptional activation were also significantly reduced in castration-resistant cells. Analysis of the UDP-sugar pools and flux through pathways downstream of UDP-glucuronate production revealed that these glucuronidation precursor metabolites were channeled through proteoglycan and glycosaminoglycan biosynthetic pathways, leading to increased surface expression of Notch1. Knockdown of UGDH diminished Notch1 and increased glucuronide output. Overall, these results support a model in which the aberrant partitioning of UDP-glucuronate and other UDP-sugars into alternative pathways during androgen deprivation contributes to the loss of prostate tumor cell androgen sensitivity by promoting altered cell surface proteoglycan expression.
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Affiliation(s)
- Brenna M Zimmer
- Department of Biochemistry, University of Nebraska, 1901 Vine Street, Lincoln, NE, 68588-0664, USA
| | - Michelle E Howell
- Department of Biochemistry, University of Nebraska, 1901 Vine Street, Lincoln, NE, 68588-0664, USA
| | - Qin Wei
- Department of Biochemistry, University of Nebraska, 1901 Vine Street, Lincoln, NE, 68588-0664, USA
| | - Linlin Ma
- Department of Biochemistry, University of Nebraska, 1901 Vine Street, Lincoln, NE, 68588-0664, USA
| | - Trevor Romsdahl
- Department of Biochemistry, University of Nebraska, 1901 Vine Street, Lincoln, NE, 68588-0664, USA
| | - Eileen G Loughman
- Department of Biochemistry, University of Nebraska, 1901 Vine Street, Lincoln, NE, 68588-0664, USA
| | - Jennifer E Markham
- Department of Biochemistry, University of Nebraska, 1901 Vine Street, Lincoln, NE, 68588-0664, USA
| | - Javier Seravalli
- Department of Biochemistry, University of Nebraska, 1901 Vine Street, Lincoln, NE, 68588-0664, USA
| | - Joseph J Barycki
- Department of Biochemistry, University of Nebraska, 1901 Vine Street, Lincoln, NE, 68588-0664, USA
| | - Melanie A Simpson
- Department of Biochemistry, University of Nebraska, 1901 Vine Street, Lincoln, NE, 68588-0664, USA.
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GuoI D, Han J, Liu W, Fu Z, Zhu Q, Tao Y. [Effects of two UDP-glucose dehydrogenases on hyaluronic acid biotransformation]. Sheng Wu Gong Cheng Xue Bao 2014; 30:1691-1700. [PMID: 25985520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We amplified genes encoding UDP-glucose dehydrogenase, ecohasB from Escherichia coli and spyhasB from Streptococcus pyogenes. Both ecohasB and spyhasB were inserted into T7 expression vector pRX2 to construct recombinant plasmids pRXEB and pRXSB, and to express in E. coli BL21(DE3). After nickel column purification of UDP-glucose dehydrogenases, the enzymes were characterized. The optimum reaction condition of spyHasB was at 30 °C and pH 10. The specific activity reached 12.2 U/mg under optimum condition. The optimum reaction condition of ecoHasB was at 30 °C and pH 9. Its specific activity reached 5.55 U/mg under optimum condition. The pmuhasA gene encoding hyaluronic acid synthase was amplified from Pasteurella multocida and ligated with ecohasB and spyhasB to construct the coexpression vectors pBPAEB and pBPASB, respectively. The co-expression vectors were transformed into E. coli BW25113. Hyaluronic acid (HA) was produced by biotransformation and the conditions were optimized. When recombinant strains were used to produce hyaluronic acid, the higher the activity of UDP-glucose dehydrogenase was, the better its stability was, and the higher the HA production could reach. Under the optimal conditions, the yields of HA produced by pBPAEB/BW25113 and pBPASB/BW25113 in shake flasks were 1.52 and 1.70 g/L, respectively, and the production increased more than 2-3 folds as previously reported.
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Gangl R, Behmüller R, Tenhaken R. Molecular cloning of a novel glucuronokinase/putative pyrophosphorylase from zebrafish acting in an UDP-glucuronic acid salvage pathway. PLoS One 2014; 9:e89690. [PMID: 24586965 PMCID: PMC3938481 DOI: 10.1371/journal.pone.0089690] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 01/23/2014] [Indexed: 12/11/2022] Open
Abstract
In animals, the main precursor for glycosaminoglycan and furthermore proteoglycan biosynthesis, like hyaluronic acid, is UDP-glucuronic acid, which is synthesized via the nucleotide sugar oxidation pathway. Mutations in this pathway cause severe developmental defects (deficiency in the initiation of heart valve formation). In plants, UDP-glucuronic acid is synthesized via two independent pathways. Beside the nucleotide sugar oxidation pathway, a second minor route to UDP-glucuronic acid exist termed the myo-inositol oxygenation pathway. Within this myo-inositol is ring cleaved into glucuronic acid, which is subsequently converted to UDP-glucuronic acid by glucuronokinase and UDP-sugar pyrophosphorylase. Here we report on a similar, but bifunctional enzyme from zebrafish (Danio rerio) which has glucuronokinase/putative pyrophosphorylase activity. The enzyme can convert glucuronic acid into UDP-glucuronic acid, required for completion of the alternative pathway to UDP-glucuronic acid via myo-inositol and thus establishes a so far unknown second route to UDP-glucuronic acid in animals. Glucuronokinase from zebrafish is a member of the GHMP-kinase superfamily having unique substrate specificity for glucuronic acid with a Km of 31±8 µM and accepting ATP as the only phosphate donor (Km: 59±9 µM). UDP-glucuronic acid pyrophosphorylase from zebrafish has homology to bacterial nucleotidyltransferases and requires UTP as nucleosid diphosphate donor. Genes for bifunctional glucuronokinase and putative UDP-glucuronic acid pyrophosphorylase are conserved among some groups of lower animals, including fishes, frogs, tunicates, and polychaeta, but are absent from mammals. The existence of a second pathway for UDP-glucuronic acid biosynthesis in zebrafish likely explains some previous contradictory finding in jekyll/ugdh zebrafish developmental mutants, which showed residual glycosaminoglycans and proteoglycans in knockout mutants of UDP-glucose dehydrogenase.
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Affiliation(s)
- Roman Gangl
- Department of Cell Biology, Division Plant Physiology, University of Salzburg, Salzburg, Austria
| | - Robert Behmüller
- Department of Cell Biology, Division Plant Physiology, University of Salzburg, Salzburg, Austria
- Department of Molecular Biology, Division of Chemistry and Bioanalytics, University of Salzburg, Salzburg, Austria
| | - Raimund Tenhaken
- Department of Cell Biology, Division Plant Physiology, University of Salzburg, Salzburg, Austria
- * E-mail:
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Santander J, Martin T, Loh A, Pohlenz C, Gatlin DM, Curtiss R. Mechanisms of intrinsic resistance to antimicrobial peptides of Edwardsiella ictaluri and its influence on fish gut inflammation and virulence. Microbiology (Reading) 2013; 159:1471-1486. [PMID: 23676433 PMCID: PMC4085987 DOI: 10.1099/mic.0.066639-0] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Accepted: 05/10/2013] [Indexed: 11/18/2022]
Abstract
The genus Edwardsiella comprises a genetically distinct taxon related to other members of the family Enterobacteriaceae. It consists of bacteria differing strongly in their biochemical and physiological features, natural habitats, and pathogenic properties. Intrinsic resistance to cationic antimicrobial peptides (CAMPs) is a specific property of the genus Edwardsiella. In particular, Edwardsiella ictaluri, an important pathogen of the catfish (Ictalurus punctatus) aquaculture and the causative agent of a fatal systemic infection, is highly resistant to CAMPs. E. ictaluri mechanisms of resistance to CAMPs are unknown. We hypothesized that E. ictaluri lipopolysaccharide (LPS) plays a role in both virulence and resistance to CAMPs. The putative genes related to LPS oligo-polysaccharide (O-PS) synthesis were in-frame deleted. Individual deletions of wibT, gne and ugd eliminated synthesis of the O-PS, causing auto-agglutination, rough colonies, biofilm-like formation and motility defects. Deletion of ugd, the gene that encodes the UDP-glucose dehydrogenase enzyme responsible for synthesis of UDP-glucuronic acid, causes sensitivity to CAMPs, indicating that UDP-glucuronic acid and its derivatives are related to CAMP intrinsic resistance. E. ictaluri OP-S mutants showed different levels of attenuation, colonization of lymphoid tissues and immune protection in zebrafish (Danio rerio) and catfish. Orally inoculated catfish with O-PS mutant strains presented different degrees of gut inflammation and colonization of lymphoid tissues. Here we conclude that intrinsic resistance to CAMPs is mediated by Ugd enzyme, which has a pleiotropic effect in E. ictaluri influencing LPS synthesis, motility, agglutination, fish gut inflammation and virulence.
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Affiliation(s)
- Javier Santander
- Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287, USA
| | - Taylor Martin
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Amanda Loh
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Camilo Pohlenz
- Department of Wildlife and Fisheries Sciences, Texas A&M University System, College Station, TX 77843, USA
| | - Delbert M. Gatlin
- Department of Wildlife and Fisheries Sciences, Texas A&M University System, College Station, TX 77843, USA
- Intercollegiate Faculty of Nutrition, Texas A&M University System, College Station, TX 77843, USA
| | - Roy Curtiss
- Biodesign Institute, Center for Infectious Diseases and Vaccinology, Arizona State University, Tempe, AZ 85287, USA
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
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11
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Siddique S, Sobczak M, Tenhaken R, Grundler FMW, Bohlmann H. Cell wall ingrowths in nematode induced syncytia require UGD2 and UGD3. PLoS One 2012; 7:e41515. [PMID: 22848518 PMCID: PMC3406070 DOI: 10.1371/journal.pone.0041515] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Accepted: 06/21/2012] [Indexed: 12/15/2022] Open
Abstract
The cyst nematode Heterodera schachtii infects roots of Arabidopsis plants and establishes feeding sites called syncytia, which are the only nutrient source for nematodes. Development of syncytia is accompanied by changes in cell wall structures including the development of cell wall ingrowths. UDP-glucuronic acid is a precursor of several cell wall polysaccharides and can be produced by UDP-glucose dehydrogenase through oxidation of UDP-glucose. Four genes in Arabidopsis encode this enzyme. Promoter::GUS analysis revealed that UGD2 and UGD3 were expressed in syncytia as early as 1 dpi while expression of UGD1 and UGD4 could only be detected starting at 2 dpi. Infection assays showed no differences between Δugd1 and Δugd4 single mutants and wild type plants concerning numbers of males and females and the size of syncytia and cysts. On single mutants of Δugd2 and Δugd3, however, less and smaller females, and smaller syncytia formed compared to wild type plants. The double mutant ΔΔugd23 had a stronger effect than the single mutants. These data indicate that UGD2 and UGD3 but not UGD1 and UGD4 are important for syncytium development. We therefore studied the ultrastructure of syncytia in the ΔΔugd23 double mutant. Syncytia contained an electron translucent cytoplasm with degenerated cellular organelles and numerous small vacuoles instead of the dense cytoplasm as in syncytia developing in wild type roots. Typical cell wall ingrowths were missing in the ΔΔugd23 double mutant. Therefore we conclude that UGD2 and UGD3 are needed for the production of cell wall ingrowths in syncytia and that their lack leads to a reduced host suitability for H. schachtii resulting in smaller syncytia, lower number of developing nematodes, and smaller females.
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Affiliation(s)
- Shahid Siddique
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Miroslaw Sobczak
- Department of Botany, Warsaw University of Life Sciences (SGGW), Warsaw, Poland
| | - Raimund Tenhaken
- Division of Plant Physiology, University of Salzburg, Salzburg, Austria
| | - Florian M. W. Grundler
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Holger Bohlmann
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna, Austria
- * E-mail:
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Eixelsberger T, Brecker L, Nidetzky B. Catalytic mechanism of human UDP-glucose 6-dehydrogenase: in situ proton NMR studies reveal that the C-5 hydrogen of UDP-glucose is not exchanged with bulk water during the enzymatic reaction. Carbohydr Res 2012; 356:209-14. [PMID: 22525098 PMCID: PMC3387377 DOI: 10.1016/j.carres.2012.03.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 03/23/2012] [Accepted: 03/24/2012] [Indexed: 11/18/2022]
Abstract
Human UDP-glucose 6-dehydrogenase (hUGDH) catalyzes the biosynthetic oxidation of UDP-glucose into UDP-glucuronic acid. The catalytic reaction proceeds in two NAD+-dependent steps via covalent thiohemiacetal and thioester enzyme intermediates. Formation of the thiohemiacetal adduct occurs through attack of Cys276 on C-6 of the UDP-gluco-hexodialdose produced in the first oxidation step. Because previous studies of the related enzyme from bovine liver had suggested loss of the C-5 hydrogen from UDP-gluco-hexodialdose due to keto-enol tautomerism, we examined incorporation of solvent deuterium into product(s) of UDP-glucose oxidation by hUGDH. We used wild-type enzyme and a slow-reacting Glu161→Gln mutant that accumulates the thioester adduct at steady state. In situ proton NMR measurements showed that UDP-glucuronic acid was the sole detectable product of both enzymatic transformations. The product contained no deuterium at C-5 within the detection limit (⩽2%). The results are consistent with the proposed mechanistic idea for hUGDH that incipient UDP-gluco-hexodialdose is immediately trapped by thiohemiacetal adduct formation.
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Affiliation(s)
- Thomas Eixelsberger
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/1, A-8010 Graz, Austria
| | - Lothar Brecker
- Institute of Organic Chemistry, University of Vienna, Währingerstraße 38, A-1090 Vienna, Austria
| | - Bernd Nidetzky
- Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/1, A-8010 Graz, Austria
- Corresponding author. Tel.: +43 316 873 8400; fax: +43 316 873 8434.
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Rajakannan V, Lee HS, Chong SH, Ryu HB, Bae JY, Whang EY, Huh JW, Cho SW, Kang LW, Choe H, Robinson RC. Structural basis of cooperativity in human UDP-glucose dehydrogenase. PLoS One 2011; 6:e25226. [PMID: 21984906 PMCID: PMC3184952 DOI: 10.1371/journal.pone.0025226] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 08/29/2011] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND UDP-glucose dehydrogenase (UGDH) is the sole enzyme that catalyzes the conversion of UDP-glucose to UDP-glucuronic acid. The product is used in xenobiotic glucuronidation in hepatocytes and in the production of proteoglycans that are involved in promoting normal cellular growth and migration. Overproduction of proteoglycans has been implicated in the progression of certain epithelial cancers, while inhibition of UGDH diminished tumor angiogenesis in vivo. A better understanding of the conformational changes occurring during the UGDH reaction cycle will pave the way for inhibitor design and potential cancer therapeutics. METHODOLOGY Previously, the substrate-bound of UGDH was determined to be a symmetrical hexamer and this regular symmetry is disrupted on binding the inhibitor, UDP-α-D-xylose. Here, we have solved an alternate crystal structure of human UGDH (hUGDH) in complex with UDP-glucose at 2.8 Å resolution. Surprisingly, the quaternary structure of this substrate-bound protein complex consists of the open homohexamer that was previously observed for inhibitor-bound hUGDH, indicating that this conformation is relevant for deciphering elements of the normal reaction cycle. CONCLUSION In all subunits of the present open structure, Thr131 has translocated into the active site occupying the volume vacated by the absent active water and partially disordered NAD+ molecule. This conformation suggests a mechanism by which the enzyme may exchange NADH for NAD+ and repolarize the catalytic water bound to Asp280 while protecting the reaction intermediates. The structure also indicates how the subunits may communicate with each other through two reaction state sensors in this highly cooperative enzyme.
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Affiliation(s)
- Venkatachalam Rajakannan
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore
| | - Hui-Sun Lee
- Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
- Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Seoul, Korea
| | - Seon-Ha Chong
- Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
- Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Seoul, Korea
| | - Han-Bong Ryu
- Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
- Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Seoul, Korea
| | - Ji-Young Bae
- Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
- Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Seoul, Korea
| | - Eun-Young Whang
- Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul, Korea
| | - Jae-Wan Huh
- Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul, Korea
| | - Sung-Woo Cho
- Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul, Korea
| | - Lin-Woo Kang
- Department of Advanced Technology Fusion, Kunkuk University, Seoul, Korea
| | - Han Choe
- Department of Physiology, University of Ulsan College of Medicine, Seoul, Korea
- Bio-Medical Institute of Technology, University of Ulsan College of Medicine, Seoul, Korea
- * E-mail:
| | - Robert C. Robinson
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research, Singapore, Singapore
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Egger S, Chaikuad A, Kavanagh KL, Oppermann U, Nidetzky B. Structure and mechanism of human UDP-glucose 6-dehydrogenase. J Biol Chem 2011; 286:23877-87. [PMID: 21502315 PMCID: PMC3129169 DOI: 10.1074/jbc.m111.234682] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Revised: 04/06/2011] [Indexed: 11/21/2022] Open
Abstract
Elevated production of the matrix glycosaminoglycan hyaluronan is strongly implicated in epithelial tumor progression. Inhibition of synthesis of the hyaluronan precursor UDP-glucuronic acid (UDP-GlcUA) therefore presents an emerging target for cancer therapy. Human UDP-glucose 6-dehydrogenase (hUGDH) catalyzes, in two NAD(+)-dependent steps without release of intermediate aldehyde, the biosynthetic oxidation of UDP-glucose (UDP-Glc) to UDP-GlcUA. Here, we present a structural characterization of the hUGDH reaction coordinate using crystal structures of the apoenzyme and ternary complexes of the enzyme bound with UDP-Glc/NADH and UDP-GlcUA/NAD(+). The quaternary structure of hUGDH is a disc-shaped trimer of homodimers whose subunits consist of two discrete α/β domains with the active site located in the interdomain cleft. Ternary complex formation is accompanied by rigid-body and restrained movement of the N-terminal NAD(+) binding domain, sequestering substrate and coenzyme in their reactive positions through interdomain closure. By alternating between conformations in and out of the active site during domain motion, Tyr(14), Glu(161), and Glu(165) participate in control of coenzyme binding and release during 2-fold oxidation. The proposed mechanism of hUGDH involves formation and breakdown of thiohemiacetal and thioester intermediates whereby Cys(276) functions as the catalytic nucleophile. Stopped-flow kinetic data capture the essential deprotonation of Cys(276) in the course of the first oxidation step, allowing the thiolate side chain to act as a trap of the incipient aldehyde. Because thiohemiacetal intermediate accumulates at steady state under physiological reaction conditions, hUGDH inhibition might best explore ligand binding to the NAD(+) binding domain.
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Affiliation(s)
- Sigrid Egger
- From the Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/1, A-8010 Graz, Austria
| | - Apirat Chaikuad
- the Structural Genomics Consortium, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, United Kingdom, and
| | - Kathryn L. Kavanagh
- the Structural Genomics Consortium, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, United Kingdom, and
| | - Udo Oppermann
- the Structural Genomics Consortium, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Headington, Oxford OX3 7DQ, United Kingdom, and
- the Botnar Research Centre, NIHR Oxford Biomedical Research Unit, University of Oxford, Oxford OX3 7LD, United Kingdom
| | - Bernd Nidetzky
- From the Institute of Biotechnology and Biochemical Engineering, Graz University of Technology, Petersgasse 12/1, A-8010 Graz, Austria
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Ariyakumar DS, Nishiguchi MK. Characterization of two host-specific genes, mannose-sensitive hemagglutinin (mshA) and uridyl phosphate dehydrogenase (UDPDH) that are involved in the Vibrio fischeri-Euprymna tasmanica mutualism. FEMS Microbiol Lett 2009; 299:65-73. [PMID: 19686342 PMCID: PMC2888660 DOI: 10.1111/j.1574-6968.2009.01732.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
While much has been known about the mutualistic associations between the sepiolid squid Euprymna tasmanica and the luminescent bacterium, Vibrio fischeri, less is known about the connectivity between the microscopic and molecular basis of initial attachment and persistence in the light organ. Here, we examine the possible effects of two symbiotic genes on specificity and biofilm formation of V. fischeri in squid light organs. Uridine diphosphate glucose-6-dehydrogenase (UDPDH) and mannose-sensitive hemagglutinin (mshA) mutants were generated in V. fischeri to determine whether each gene has an effect on host colonization, specificity, and biofilm formation. Both squid light organ colonization assays and transmission electron microscopy confirmed differences in host colonization between wild-type and mutant strains, and also demonstrated the importance of both UDPDH and mshA gene expression for successful light organ colonization. This furthers our understanding of the genetic factors playing important roles in this environmentally transmitted symbiosis.
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Chien LJ, Lee CK. Hyaluronic acid production by recombinant Lactococcus lactis. Appl Microbiol Biotechnol 2007; 77:339-46. [PMID: 17805528 DOI: 10.1007/s00253-007-1153-z] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2007] [Revised: 07/24/2007] [Accepted: 07/31/2007] [Indexed: 10/22/2022]
Abstract
Microbial hyaluronic acid (HA), commonly produced by pathogenic Streptococcus, was made possible to be produced by a generally recognized as safe Lactococcus lactis by coexpressing HA synthase and uridine diphosphate-glucose dehydrogenase (UDP-GlcDH) of Streptococcus equi subsp. zooepidemicus in a nisin-controlled expression (NICE) system. With scarce expressed HA synthase alone, the constructed recombinant L. lactis (LL-NA) strain could produce HA with a concentration about 0.08 g/l in the M17 medium supplemented with 1% (w/v) glucose. In contrast to HA synthase, UDP-GlcDH of Streptococcus could be overexpressed in the NICE system. With coexpression of heterologous UDP-GlcDH with HA synthase, the constructed LL-NAB strain grew slightly slower to a concentration about 10% lower that of the LL-NA strain. However, the HA concentration produced was enhanced about eightfold to 0.65 g/l.
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Affiliation(s)
- Liang-Jung Chien
- Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei, 106, Taiwan
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Abstract
Hyaluronan (HA) is a sugar polymer of a repeating disaccharide, beta1-3 D-N-acetylglucosamine (GlcNAc) beta1-4 D-glucuronic acid (GlcA). It finds applications in numerous biomedical procedures such as ophthalmic surgery and osteoarthritis treatment. Until recently, the only commercial sources were extraction of rooster combs and from fermentation of pathogenic Streptococcus. In this work, we demonstrate that metabolic engineering strategies enable the recombinant synthesis of hyaluronan in a safe microorganism. Agrobacterium sp. ATCC 31749 is a commercial production strain for a food polymer, Curdlan. A broad host range expression vector was successfully developed to express the 3 kb HA synthase gene from Pasteurella multocida, along with a kfiD gene encoding UDP-glucose dehydrogenase from Escherichia coli K5 strain. Coexpression of these two heterologous enzymes enables Agrobacterium to produce HA. Hyaluronan was accumulated up to 0.3 g/L in shaker flask cultivation. The molecular weight of the polymer from various Agrobacterium strains is in the range of 0.7-2 MD. To our knowledge, this is the first successful recombinant hyaluronan synthesis in a Gram-negative bacterium that naturally produces a food product. The ease of genetic modifications provides future opportunities to tailor properties of polymers for specific applications.
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Affiliation(s)
- Zichao Mao
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, Georgia 30332-0100, USA
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Granja AT, Popescu A, Marques AR, Sá-Correia I, Fialho AM. Biochemical characterization and phylogenetic analysis of UDP-glucose dehydrogenase from the gellan gum producer Sphingomonas elodea ATCC 31461. Appl Microbiol Biotechnol 2007; 76:1319-27. [PMID: 17668199 DOI: 10.1007/s00253-007-1112-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 07/03/2007] [Accepted: 07/04/2007] [Indexed: 10/23/2022]
Abstract
Sphingomonas elodea ATCC 31461 synthesizes in high yield the exopolysaccharide gellan, which is a water-soluble gelling agent with many applications. In this study, we describe the cloning and sequence analysis of the ugdG gene, encoding a UDP-glucose dehydrogenase (47.2 kDa; UDPG-DH; EC 1.1.1.22), required for the synthesis of the gellan gum precursor UDP-glucuronic acid. UgdG protein shows homology to members of the UDP-glucose/GDP-mannose dehydrogenase superfamily. The Neighbor-Joining method was used to determine phylogenetic relationships among prokaryotic and eukaryotic UDPG-DHs. UgdG from S. elodea and UDPG-DHs from Novosphingobium, Zymomonas, Agrobacterium, and Caulobacter species form a divergent phylogenetic group with a close evolutionary relationship with eukaryotic UDPG-DHs. The ugdG gene was recombinantly expressed in Escherichia coli with and N-terminal 6-His tag and purified for biochemical characterization. The enzyme has an optimum temperature and pH of 37 degrees C and 8.7, respectively. The estimated apparent K(m) values for UDP-glucose and NAD(+) were 0.87 and 0.4 mM, respectively. DNA sequencing of chromosomal regions adjacent to ugdG gene and sequence similarity studies suggests that this gene maps together with others presumably involved in the biosynthesis of S. elodea cell wall polysaccharides.
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Affiliation(s)
- Ana Teresa Granja
- IBB - Institute for Biotechnology and Bioengineering, Centre for Biological and Chemical Engineering, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
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Hung RJ, Chien HS, Lin RZ, Lin CT, Vatsyayan J, Peng HL, Chang HY. Comparative analysis of two UDP-glucose dehydrogenases in Pseudomonas aeruginosa PAO1. J Biol Chem 2007; 282:17738-48. [PMID: 17442666 DOI: 10.1074/jbc.m701824200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
UDP-glucose dehydrogenase (UGDH) catalyzes a two-step NAD(+)-dependent oxidation of UDP-glucose to produce UDP-glucuronic acid, which is a common substrate for the biosynthesis of exopolysaccharide. Searching the Pseudomonas aeruginosa PAO1 genome data base for a UGDH has helped identify two open reading frames, PA2022 and PA3559, which may encode a UGDH. To elucidate their enzymatic identity, the two genes were cloned and overexpressed in Escherichia coli, and the recombinant proteins were purified. Both the gene products are active as dimers and are capable of utilizing UDP-glucose as a substrate to generate UDP-glucuronic acid. The K(m) values of PA2022 and PA3559 for UDP-glucose are approximately 0.1 and 0.4 mM, whereas the K(m) values for NAD(+) are 0.5 and 2.0 mM, respectively. Compared with PA3559, PA2022 exhibits broader substrate specificity, utilizing TDP-glucose and UDP-N-acetylglucosamine with one-third the velocity of that with UDP-glucose. The PA2022 mutant and PA2022-PA3559 double mutant, but not the PA3559 mutant, are more susceptible to chloramphenicol, cefotaxime, and ampicillin. The PA3559 mutant, however, shows a reduced resistance to polymyxin B compared with wild type PAO1. Finally, real time PCR analysis indicates that PA3559 is expressed primarily in low concentrations of Mg(2+), which contrasts with the constitutive expression of PA2022. Although both the enzymes catalyze the same reaction, their enzymatic properties and gene expression profiles indicate that they play distinct physiological roles in P. aeruginosa, as reflected by different phenotypes displayed by the mutants.
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Affiliation(s)
- Ruei-Jiun Hung
- Institute of Molecular Medicine, National Tsing Hua University, Hsin Chu 300, Taiwan
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Easley KE, Sommer BJ, Boanca G, Barycki JJ, Simpson MA. Characterization of human UDP-glucose dehydrogenase reveals critical catalytic roles for lysine 220 and aspartate 280. Biochemistry 2007; 46:369-78. [PMID: 17209547 DOI: 10.1021/bi061537d] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Human UDP-glucose dehydrogenase (UGDH) is a homohexameric enzyme that catalyzes two successive oxidations of UDP-glucose to yield UDP-glucuronic acid, an essential precursor for matrix polysaccharide and proteoglycan synthesis. We previously used crystal coordinates for Streptococcus pyogenes UGDH to generate a model of the human enzyme active site. In the studies reported here, we have used this model to identify three putative active site residues: lysine 220, aspartate 280, and lysine 339. Each residue was site-specifically mutagenized to evaluate its importance for catalytic activity and maintenance of hexameric quaternary structure. Alteration of lysine 220 to alanine, histidine, or arginine significantly impaired enzyme function. Assaying activity over longer time courses revealed a plateau after reduction of a single equivalent of NAD+ in the alanine and histidine mutants, whereas turnover continued in the arginine mutant. Thus, one role of this lysine may be to stabilize anionic transition states during substrate conversion. Mutation of aspartate 280 to asparagine was also severely detrimental to catalysis. The relative position of this residue within the active site and dependence of function on acidic character point toward a critical role for aspartate 280 in activation of the substrate and the catalytic cysteine. Finally, changing lysine 339 to alanine yielded the wild-type Vmax, but a 165-fold decrease in affinity for UDP-glucose. Interestingly, gel filtration of this substrate-binding mutant also determined it was a dimer, indicating that hexameric quaternary structure is not critical for catalysis. Collectively, this analysis has provided novel insights into the complex catalytic mechanism of UGDH.
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Affiliation(s)
- Katherine E Easley
- Department of Biochemistry, University of Nebraska, Lincoln, Nebraska 68588-0664, USA
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Klinghammer M, Tenhaken R. Genome-wide analysis of the UDP-glucose dehydrogenase gene family in Arabidopsis, a key enzyme for matrix polysaccharides in cell walls. J Exp Bot 2007; 58:3609-21. [PMID: 18057039 DOI: 10.1093/jxb/erm209] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Arabidopsis cell walls contain large amounts of pectins and hemicelluloses, which are predominantly synthesized via the common precursor UDP-glucuronic acid. The major enzyme for the formation of this nucleotide-sugar is UDP-glucose dehydrogenase, catalysing the irreversible oxidation of UDP-glucose into UDP-glucuronic acid. Four functional gene family members and one pseudogene are present in the Arabidopsis genome, and they show distinct tissue-specific expression patterns during plant development. The analyses of reporter gene lines indicate gene expression of UDP-glucose dehydrogenases in growing tissues. The biochemical characterization of the different isoforms shows equal affinities for the cofactor NAD(+) ( approximately 40 microM) but variable affinities for the substrate UDP-glucose (120-335 microM) and different catalytic constants, suggesting a regulatory role for the different isoforms in carbon partitioning between cell wall formation and sucrose synthesis as the second major UDP-glucose-consuming pathway. UDP-glucose dehydrogenase is feedback inhibited by UDP-xylose. The relatively (compared with a soybean UDP-glucose dehydrogenase) low affinity of the enzymes for the substrate UDP-glucose is paralleled by the weak inhibition of the enzymes by UDP-xylose. The four Arabidopsis UDP-glucose dehydrogenase isoforms oxidize only UDP-glucose as a substrate. Nucleotide-sugars, which are converted by similar enzymes in bacteria, are not accepted as substrates for the Arabidopsis enzymes.
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Affiliation(s)
- Michaela Klinghammer
- University of Frankfurt, Plant Molecular Biology, Biocenter, D-60439 Frankfurt, Germany
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22
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Huh JW, Robinson RC, Lee HS, Lee JI, Heo YS, Kim HT, Lee HJ, Cho SW, Choe H. Expression, purification, crystallization, and preliminary X-Ray analysis of the human UDP-glucose dehydrogenase. Protein Pept Lett 2006; 13:859-62. [PMID: 17073734 DOI: 10.2174/092986606777841253] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
UDP-glucose dehydrogenase (UGDH) catalyzes the synthesis of UDP-glucuronic acid from UDP-glucose resulting in the formation of proteoglycans that are involved in promoting normal cellular growth and migration. Overproduction of proteoglycans has been implicated in the progression of certain epithelial cancers. Here, human UGDH (hUGDH) was purified and crystallized from a solution of 0.2 M ammonium sulfate, 0.1 M Na cacodylate, pH 6.5, and 21% PEG 8000. Diffraction data were collected to a resolution of 2.8 A. The crystal belongs to the orthorhombic space group P2(1)2(1)2(1) with unit-cell parameters a = 173.25, b = 191.16, c = 225.94 A, and alpha = beta = gamma = 90.0 degrees. Based on preliminary analysis of the diffraction data, we propose that the biological unit of hUGDH is a tetramer.
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Affiliation(s)
- Jae Wan Huh
- Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul 138-736, South Korea
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23
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McEllistrem MC, Ransford JV, Khan SA. Characterization of in vitro biofilm-associated pneumococcal phase variants of a clinically relevant serotype 3 clone. J Clin Microbiol 2006; 45:97-101. [PMID: 17093036 PMCID: PMC1828957 DOI: 10.1128/jcm.01658-06] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
An increasing proportion of children with acute otitis media due to Streptococcus pneumoniae have serotype 3 infections since licensure of the seven-valent pneumococcal conjugate vaccine. These serotype 3 strains are genetically related by molecular subtyping. During otitis media with effusion and recurrent otitis media, biofilms commonly develop. Pneumococcal in vitro biofilms are comprised of phase variants that differ in colony morphology. By using a representative strain of the mucoid serotype 3 clone, rough phase variants with a diverse array of mutations were detected in biofilms formed in vitro. Most phase variants had mutations in the cps3D gene, the first gene of the capsular operon. Eleven had single nucleotide polymorphisms (SNPs) in the cps3D gene, one had an SNP in the -10 promoter, and three had large deletions in the cps3D gene. Reversion to the mucoid phenotype was associated with reversion of the mutation in the cps3D gene. Unlike the phase variants detected in the nasopharynx, which have at least 20% of the parental amount of capsule, the in vitro biofilm-associated phase variants had < or =12% of the parental amount of capsule, as determined by capsule enzyme-linked immunosorbent assays. Using real-time reverse transcription-PCR, we determined that capsule expression in the phase variants was likely regulated at multiple levels. These in vitro phase variation data, which underscore the plasticity of the pneumococcus, need to be confirmed with in vivo analyses of the middle ear mucosa during otitis media.
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Affiliation(s)
- M Catherine McEllistrem
- Division of Infectious Diseases, University of Pittsburgh School of Medicine, PA 15213-2582, USA.
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24
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Abstract
UDP-glucuronosyltransferases (UGTs) catalyze phase II biotransformation reactions in which lipophilic substrates are conjugated with glucuronic acid to increase water solubility and enhance excretion. Currently, little information regarding tissue- or gender-specific expression of mouse UGTs is available. Mice are increasingly popular models in biomedical research, and therefore, thorough characterization of murine drug metabolism is desired. The purpose of the present study was to determine both tissue- and gender-specific UGT gene expression profiles in mice. RNA from 14 tissues was isolated from male and female C57BL/6 mice and UGT expression was determined by the branched DNA signal amplification assay. UGTs highly expressed in mouse liver include Ugt1a1, Ugt1a5, Ugt1a6, Ugt1a9, Ugt2a3, Ugt2b1, Ugt2b5/37/38, Ugt2b34, Ugt2b35, and Ugt2b36. Several isoforms were expressed in the gastrointestinal (GI) tract, including Ugt1a6, Ugt1a7c, Ugt2a3, Ugt2b34, and Ugt2b35. In kidney, Ugt1a2, Ugt1a7c, Ugt2b5/37/38, Ugt2b35, and Ugt3a1/2 were expressed. UGT expression was also observed in other tissues: lung (Ugt1a6), brain (Ugt2b35), testis and ovary (Ugt1a6 and Ugt2b35), and nasal epithelia (Ugt2a1/2). Male-predominant expression was observed for Ugt2b1 in liver, Ugt2b5/37/38 in kidney, and Ugt1a6 in lung. Female-predominant expression was observed for Ugt1a1 and Ugt1a5 in liver, Ugt1a2 in kidney, Ugt2b35 in brain, and Ugt2a1/2 in nasal epithelia. UDP-glucose pyrophosphorylase was highly expressed in liver, kidney, and GI tract, whereas UDP-glucose dehydrogenase was highly expressed in the GI tract. In conclusion, marked differences in tissue- and gender-specific expression patterns of UGTs exist in mice, potentially influencing drug metabolism and pharmacokinetics.
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Affiliation(s)
- David B Buckley
- Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160-7417, USA.
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25
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Blanch M, Legaz ME, Vicente C. Purification and properties of an unusual UDP-glucose dehydrogenase, NADPH-dependent, from Xanthomonas albilineans. Microbiol Res 2006; 163:362-71. [PMID: 17010583 DOI: 10.1016/j.micres.2006.07.011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2006] [Revised: 07/12/2006] [Accepted: 07/18/2006] [Indexed: 11/28/2022]
Abstract
Xanthomonas albilineans produces a UDP-glucose dehydrogenase growing on sucrose. The enzyme oxidizes UDP-glucose to UDP-glucuronic acid by using molecular oxygen and NADPH. Kinetics of enzymatic oxydation of NADPH is linearly dependent on the amount of oxygen supplied. The enzyme has been purified at homogeneity. The value of pI of the purified enzyme is 8.98 and its molecular mass has been estimated as about 14 kDa. The enzyme shows a michaelian kinetics for UDP-glucose concentrations. The value of K(m) for UDP-glucose is 0.87 mM and 0.26 mM for NADPH, although the enzyme has three different sites to interact with NADPH. The enzyme is inhibited by UDP-glucose concentrations higher than 1.3 mM. N-Terminal sequence has been determined as IQPYNH.
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Affiliation(s)
- María Blanch
- Laboratory of Plant Physiology, Faculty of Biology, Complutense University, Madrid, Spain
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26
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Abstract
UDP-D-glucuronic acid and UDP-D-xylose are required for the biosynthesis of glycosaminoglycan in mammals and of cell wall polysaccharides in plants. Given the importance of these glycans to some organisms, the development of a system for production of UDP-D-glucuronic acid and UDP-D-xylose from a common precursor could prove useful for a number of applications. The budding yeast Saccharomyces cerevisiae lacks an endogenous ability to synthesize or consume UDP-D-glucuronic acid and UDP-D-xylose. However, yeast have a large cytoplasmic pool of UDP-D-glucose that could be used to synthesize cell wall beta-glucan, as a precursor of UDP-D-glucuronic acid and UDP-D-xylose. Thus, if a mechanism for converting the precursors into the end-products can be identified, yeast may be harnessed as a system for production of glycans. Here we report a novel S. cerevisiae strain that coexpresses the Arabidopsis thaliana genes UGD1 and UXS3, which encode a UDP-glucose dehydrogenase (AtUGD1) and a UDP-glucuronic acid decarboxylase (AtUXS3), respectively, which are required for the conversion of UDP-D-glucose to UDP-D-xylose in plants. The recombinant yeast strain was capable of converting UDP-D-glucose to UDP-D-glucuronic acid, and UDP-D-glucuronic acid to UDP-D-xylose, in the cytoplasm, demonstrating the usefulness of this yeast system for the synthesis of glycans. Furthermore, we observed that overexpression of AtUGD1 caused a reduction in the UDP-D-glucose pool, whereas coexpression of AtUXS3 and AtUGD1 did not result in reduction of the UDP-D-glucose pool. Enzymatic analysis of the purified hexamer His-AtUGD1 revealed that AtUGD1 activity is strongly inhibited by UDP-D-xylose, suggesting that AtUGD1 maintains intracellular levels of UDP-D-glucose in cooperation with AtUXS3 via the inhibition of AtUGD1 by UDP-D-xylose.
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Affiliation(s)
- Takuji Oka
- Research Center for Glycoscience, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Japan
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27
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Ventura CL, Cartee RT, Forsee WT, Yother J. Control of capsular polysaccharide chain length by UDP-sugar substrate concentrations in Streptococcus pneumoniae. Mol Microbiol 2006; 61:723-33. [PMID: 16780566 DOI: 10.1111/j.1365-2958.2006.05259.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Regulation of chain length is essential to the proper functioning of prokaryotic and eukaryotic polysaccharides. Modulation of polymer size by substrate concentration is an attractive but unexplored control mechanism that has been suggested for many polysaccharides. The Streptococcus pneumoniae capsular polysaccharide is essential for virulence, and regulation of its size is critical for survival in different host environments. Synthesis of the type 3 capsule [-4)-beta-d-Glc-(1-3)-beta-d-GlcUA-(1-] from UDP-glucose (UDP-Glc) and UDP-glucuronic acid (UDP-GlcUA) is catalysed by the type 3 synthase, a processive beta-glycosyltransferase, and requires a UDP-Glc dehydrogenase for conversion of UDP-Glc to UDP-GlcUA. Strains containing mutant UDP-Glc dehydrogenases exhibited reduced levels of UDP-GlcUA, along with reductions in total capsule amount and polymer chain length. In both the parent and mutant strains, UDP-Glc levels far exceeded UDP-GlcUA levels, which were very low to undetectable in the absence of blocking synthase activity. The in vivo observations were consistent with in vitro conditions that effect chain termination and ejection of the polysaccharide from the synthase when one substrate is limiting. These data are the first to demonstrate modulation of polysaccharide chain length by substrate concentration and to enable a model for the underlying mechanism. Further, they may have implications for the control of chain length in both prokaryotic and eukaryotic polymers synthesized by similar mechanisms.
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Affiliation(s)
- Christy L Ventura
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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28
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Ishiyama N, Creuzenet C, Miller WL, Demendi M, Anderson EM, Harauz G, Lam JS, Berghuis AM. Structural studies of FlaA1 from Helicobacter pylori reveal the mechanism for inverting 4,6-dehydratase activity. J Biol Chem 2006; 281:24489-95. [PMID: 16651261 DOI: 10.1074/jbc.m602393200] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
FlaA1 from the human pathogen Helicobacter pylori is an enzyme involved in saccharide biosynthesis that has been shown to be essential for pathogenicity. Here we present five crystal structures of FlaA1 in the presence of substrate, inhibitors, and bound cofactor, with resolutions ranging from 2.8 to 1.9 A. These structures reveal that the enzyme is a novel member of the short-chain dehydrogenase/reductase superfamily. Additional electron microscopy studies show the enzyme to possess a hexameric doughnut-shaped quaternary structure. NMR analyses of "real time" enzyme-substrate reactions indicate that FlaA1 is a UDP-GlcNAc-inverting 4,6-dehydratase, suggesting that the enzyme catalyzes the first step in the biosynthetic pathway of a pseudaminic acid derivative, which is implicated in protein glycosylation. Guided by evidence from site-directed mutagenesis and computational simulations, a three-step reaction mechanism is proposed that involves Lys-133 functioning as both a catalytic acid and base.
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Affiliation(s)
- Noboru Ishiyama
- Department of Biochemistry and Department of Microbiology and Immunology, McGill University, Montreal, Quebec
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29
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Kärkönen A, Fry SC. Novel characteristics of UDP-glucose dehydrogenase activities in maize: non-involvement of alcohol dehydrogenases in cell wall polysaccharide biosynthesis. Planta 2006; 223:858-70. [PMID: 16453102 DOI: 10.1007/s00425-005-0207-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2005] [Accepted: 06/13/2005] [Indexed: 05/06/2023]
Abstract
UDP-glucose dehydrogenase (UDPGDH) activity was detected in extracts of maize cell-cultures and developing leaves. The reaction product was confirmed as UDP-glucuronate. Leaf extracts from null mutants defective in one or both of the ethanol dehydrogenase genes, ADH1 and ADH2, had similar UDPGDH activities to wild-type, showing that UDPGDH activity is not primarily due to ADH proteins. The mutants showed no defect in their wall matrix pentose:galactose ratios, or matrix:cellulose ratio, showing that ADHs were not required for normal wall biosynthesis. The majority of maize leaf UDPGDH activity had K (m) (for UDP-glucose) 0.5-1.0 mM; there was also a minor activity with an unusually high K (m) of >50 mM. In extracts of cultured cells, kinetic data indicated at least three UDPGDHs, with K (m) values (for UDP-glucose) of roughly 0.027, 2.8 and >50 mM (designated enzymes E(L), E(M) and E(H) respectively). E(M) was the single major contributor to extractable UDPGDH activity when assayed at 0.6-9.0 mM UDP-Glc. Most studies, in other plant species, had reported only E(L)-like isoforms. Ethanol (100 mM) partially inhibited UDPGDH activity assayed at low, but not high, UDP-glucose concentrations, supporting the conclusion that at least E(H) activity is not due to ADH. At 30 microM UDP-glucose, 20-150 microM UDP-xylose inhibited UDPGDH activity, whereas 5-15 microM UDP-xylose promoted it. In conclusion, several very different UDPGDH isoenzymes contribute to UDP-glucuronate and hence wall matrix biosynthesis in maize, but ADHs are not responsible for these activities.
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Affiliation(s)
- Anna Kärkönen
- The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, UK
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30
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Kärkönen A, Murigneux A, Martinant JP, Pepey E, Tatout C, Dudley B, Fry S. UDP-glucose dehydrogenases of maize: a role in cell wall pentose biosynthesis. Biochem J 2006; 391:409-15. [PMID: 15969652 PMCID: PMC1276940 DOI: 10.1042/bj20050800] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
UDPGDH (UDP-D-glucose dehydrogenase) oxidizes UDP-Glc (UDP-D-glucose) to UDP-GlcA (UDP-D-glucuronate), the precursor of UDP-D-xylose and UDP-L-arabinose, major cell wall polysaccharide precursors. Maize (Zea mays L.) has at least two putative UDPGDH genes (A and B), according to sequence similarity to a soya bean UDPGDH gene. The predicted maize amino acid sequences have 95% similarity to that of soya bean. Maize mutants with a Mu-element insertion in UDPGDH-A or UDPGDH-B were isolated (udpgdh-A1 and udpgdh-B1 respectively) and studied for changes in wall polysaccharide biosynthesis. The udpgdh-A1 and udpgdh-B1 homozygotes showed no visible phenotype but exhibited 90 and 60-70% less UDPGDH activity respectively than wild-types in a radiochemical assay with 30 microM UDP-glucose. Ethanol dehydrogenase (ADH) activity varied independently of UDPGDH activity, supporting the hypothesis that ADH and UDPGDH activities are due to different enzymes in maize. When extracts from wild-types and udpgdh-A1 homozygotes were assayed with increasing concentrations of UDP-Glc, at least two isoforms of UDPGDH were detected, having K(m) values of approx. 380 and 950 microM for UDP-Glc. Leaf and stem non-cellulosic polysaccharides had lower Ara/Gal and Xyl/Gal ratios in udpgdh-A1 homozygotes than in wild-types, whereas udpgdh-B1 homozygotes exhibited more variability among individual plants, suggesting that UDPGDH-A activity has a more important role than UDPGDH-B in UDP-GlcA synthesis. The fact that mutation of a UDPGDH gene interferes with polysaccharide synthesis suggests a greater importance for the sugar nucleotide oxidation pathway than for the myo-inositol pathway in UDP-GlcA biosynthesis during post-germinative growth of maize.
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Affiliation(s)
- Anna Kärkönen
- *The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, Daniel Rutherford Building, The King's Buildings, Edinburgh EH9 3JH, U.K
| | - Alain Murigneux
- †BIOGEMMA, Campus Universitaire des Cézeaux, 24, Avenue des Landais, 63170 Aubière, France
| | - Jean-Pierre Martinant
- †BIOGEMMA, Campus Universitaire des Cézeaux, 24, Avenue des Landais, 63170 Aubière, France
| | - Elodie Pepey
- †BIOGEMMA, Campus Universitaire des Cézeaux, 24, Avenue des Landais, 63170 Aubière, France
| | - Christophe Tatout
- †BIOGEMMA, Campus Universitaire des Cézeaux, 24, Avenue des Landais, 63170 Aubière, France
| | - Bernard J. Dudley
- *The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, Daniel Rutherford Building, The King's Buildings, Edinburgh EH9 3JH, U.K
| | - Stephen C. Fry
- *The Edinburgh Cell Wall Group, Institute of Molecular Plant Sciences, School of Biological Sciences, The University of Edinburgh, Daniel Rutherford Building, The King's Buildings, Edinburgh EH9 3JH, U.K
- To whom correspondence should be addressed (email )
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31
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Huh JW, Choi MM, Yang SJ, Yoon SY, Choi SY, Cho SW. Inhibition of human UDP-glucose dehydrogenase expression using siRNA expression vector in breast cancer cells. Biotechnol Lett 2005; 27:1229-32. [PMID: 16158268 DOI: 10.1007/s10529-005-0022-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2005] [Revised: 06/13/2005] [Accepted: 06/13/2005] [Indexed: 12/13/2022]
Abstract
UDP-glucose dehydrogenase (UGDH) catalyzes two oxidations of UDP-glucose to yield UDP-glucuronic acid. Pathological over-production of extracellular matrix components may be linked to the availability of UDP-glucuronic acid, therefore UGDH is a potential therapeutic target. RNA interference (RNAi) has been adapted to knock down the expression of human UGDH. A UGDH siRNA plasmid was constructed using a pRNA-U6.1/Neo vector and transfected into breast cancer cells, ZR-75-1, with an efficiency of up to 50%. Western blot analysis showed that the UGDH expression was efficiently knocked down at protein levels by RNAi in ZR-75-1 cells.
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Affiliation(s)
- Jae-Wan Huh
- Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, 388-1 Poongnap-dong, 138-736, Seoul, Songpa-gu, Korea
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Huh JW, Lee HJ, Choi MM, Yang SJ, Yoon SY, Kim DW, Kim SY, Choi SY, Cho SW. Identification of a UDP-glucose-binding site of human UDP-glucose dehydrogenase by photoaffinity labeling and cassette mutagenesis. Bioconjug Chem 2005; 16:710-6. [PMID: 15898741 DOI: 10.1021/bc0500387] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We have identified a UDP-glucose-binding site within human UDP-glucose dehydrogenase (hUGDH) by photoaffinity labeling with a specific probe, [(32)P]5N(3)UDP-glucose, and cassette mutagenesis using a synthetic hUGDH gene. Photolabel-containing peptides were generated by photolysis followed by tryptic digestion and isolated using the phosphopeptide isolation kit. Photolabeling of these peptides was effectively prevented by the presence of UDP-glucose during photolysis, demonstrating a selectivity of the photoprobe for the UDP-glucose-binding site. Amino acid sequencing and compositional analysis identified the UDP-glucose-binding site of hUGDH as the region containing the sequence, ASVGFGGSXFQK, corresponding to A268-K279 of the amino acid sequence of hUGDH. The unidentified residue, X, can be designated as a photolabeled C276 because the sequences including the cysteine residue in question have a complete identity with those of other UGDH species known. The importance of the C276 residue in the binding of UDP-glucose was further examined with mutant proteins at the C276 site. The mutagenesis at C276 has no effect on the expression of the mutants (C276G, C276K, C276E, C276L, and C276Y). Enzyme activities of the C276 mutants were not measurable under normal assay conditions, suggesting an important role for the C276 residue. No incorporation of [(32)P]5N(3)UDP-glucose was also observed for the mutants. These results indicate that C276 plays an important role for efficient binding of UDP-glucose to hUGDH.
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Affiliation(s)
- Jae-Wan Huh
- Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul 138-736, Korea
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33
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Beauchef G, Kypriotou M, Chadjichristos C, Widom RL, Porée B, Renard E, Moslemi S, Wegrowski Y, Maquart FX, Pujol JP, Galéra P. c-Krox down-regulates the expression of UDP–glucose dehydrogenase in chondrocytes. Biochem Biophys Res Commun 2005; 333:1123-31. [PMID: 15982635 DOI: 10.1016/j.bbrc.2005.06.020] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2005] [Accepted: 06/02/2005] [Indexed: 11/26/2022]
Abstract
Chondrocyte glycosaminoglycan (GAG) synthesis is regulated by the availability of UDP-glucuronate, the substrate of glucuronosyl transferases which form the GAG chains in proteoglycans and hyaluronan. UDP-glucose dehydrogenase (UDPGD) is therefore a key enzyme in the synthesis of UDP-glucuronate from glucose. However, the mechanisms regulating its expression in chondrocytes are not fully understood. We investigated the effect of c-Krox, a zinc-finger transcription factor previously shown to modulate several matrix genes, on the synthesis of GAG and transcriptional activity of several UDPGD gene promoter constructs, using transient transfection and decoy experiments in rabbit articular chondrocytes (RACs). We show that overexpression of c-Krox inhibits radiosulfate incorporation into neosynthesized GAG and that the effect was mediated by a cis-sequence located between +18 and +39bp of the UDPGD gene. Since that sequence can also bind Sp1/Sp3 factors, it is likely that c-Krox acts in concert with these proteins to modulate the UDPGD gene expression in articular chondrocytes.
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Affiliation(s)
- Gallic Beauchef
- Laboratory of Connective Tissue Biochemistry, Faculty of Medicine, Caen, France
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34
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Van Laer L, Pfister M, Thys S, Vrijens K, Mueller M, Umans L, Serneels L, Van Nassauw L, Kooy F, Smith RJH, Timmermans JP, Van Leuven F, Van Camp G. Mice lacking Dfna5 show a diverging number of cochlear fourth row outer hair cells. Neurobiol Dis 2005; 19:386-99. [PMID: 16023581 DOI: 10.1016/j.nbd.2005.01.019] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2004] [Accepted: 01/12/2005] [Indexed: 10/25/2022] Open
Abstract
A complex mutation in DFNA5, resulting in exon 8 skipping, causes autosomal dominant hearing impairment, which starts in the high frequencies between 5 and 15 years of age and progressively affects all frequencies. To study its function in vivo, Dfna5 knockout mice were generated through the deletion of exon 8, simultaneously mimicking the human mutation. To test the hearing impairment, frequency-specific Auditory Brainstem Response (ABR) measurements were performed at different ages in two genetic backgrounds (C57Bl/6J and CBA/Ca), but no differences between Dfna5-/- and Dfna5+/+ mice could be demonstrated. Morphological studies demonstrated significant differences in the number of fourth row outer hair cells between Dfna5-/- mice and their wild-type littermates. These results were obtained in both genetic backgrounds, albeit with opposite effects. In contrast to the results obtained in Dfna5-/- zebrafish, we did not observe different UDP-glucose dehydrogenase and hyaluronic acid levels in Dfna5-/- mice when compared to Dfna5+/+ mice.
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MESH Headings
- Animals
- Blotting, Western
- Cochlea/ultrastructure
- Disease Models, Animal
- Evoked Potentials, Auditory, Brain Stem/physiology
- Genotype
- Hair Cells, Auditory, Outer/ultrastructure
- Hearing Loss/congenital
- Hearing Loss/pathology
- Hyaluronic Acid/metabolism
- Mice
- Mice, Knockout
- Microscopy, Electron, Scanning
- Receptors, Estrogen/deficiency
- Reverse Transcriptase Polymerase Chain Reaction
- Uridine Diphosphate Glucose Dehydrogenase/metabolism
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Affiliation(s)
- Lut Van Laer
- Department of Medical Genetics, University of Antwerp, Campus Drie Eiken, Universiteitsplein 1, B-2610 Antwerp, Belgium
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35
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Mijakovic I, Petranovic D, Deutscher J. How tyrosine phosphorylation affects the UDP-glucose dehydrogenase activity of Bacillus subtilis YwqF. J Mol Microbiol Biotechnol 2005; 8:19-25. [PMID: 15741737 DOI: 10.1159/000082077] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The UDP-glucose dehydrogenase activity of Bacillus subtilis YwqF is regulated by reversible phosphorylation on a tyrosine residue. This reaction, which is catalyzed by the protein-tyrosine kinase YwqD, activates the enzyme, while dephosphorylation of phosphotyrosine-YwqF by the phosphotyrosine-protein phosphatase YwqE reduces its enzyme activity. Our kinetic data indicate that the phosphorylated and unphosphorylated forms of YwqF differ in binding the substrates. The UDP-glucose dehydrogenase reaction catalyzed by YwqF is inhibited by one of its substrates, UDP-glucose, and the extent of this inhibition seems to be reduced upon YwqF phosphorylation. We propose that this effect could at least partly account for the observed activation of YwqF induced by tyrosine phosphorylation. Potential physiological implications of this finding are discussed.
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Affiliation(s)
- Ivan Mijakovic
- Microbiologie et Génétique Moléculaire, CNRS/INRA/INA-PG UMR 2585, Thiverval-Grignon, France.
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36
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Bindschedler LV, Wheatley E, Gay E, Cole J, Cottage A, Bolwell GP. Characterisation and expression of the pathway from UDP-glucose to UDP-xylose in differentiating tobacco tissue. Plant Mol Biol 2005; 57:285-301. [PMID: 15821883 DOI: 10.1007/s11103-004-7795-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/07/2004] [Accepted: 12/16/2004] [Indexed: 05/24/2023]
Abstract
The pathway from UDP-glucose to UDP-xylose has been characterised in differentiating tobacco tissue. A xylogenic suspension cell culture of tobacco has been used as a source for the purification of the enzymes responsible for the oxidation of UDP-glucose to UDP-glucuronic acid and its subsequent decarboxylation to UDP-xylose. Protein purification and transcriptional studies show that two possible candidates can contribute to the first reaction. Most of the enzyme activity in the cultured cells could be accounted for by a protein with an Mr of 43 kDa which had dual specificity for UDP-glucose and ethanol. The cognate cDNA, with similarity to alcohol dehydrogenases (NtADH2) was expressed in E. coli to confirm the dual specificity. A second UDP-glucose dehydrogenase, corresponding to the monospecific form, ubiquitous amongst plants and animals, could not be purified from the tobacco cell cultures. However, two cDNAs were cloned with high similarity to the family of UDP-glucose dehydrogenases. Transcripts of both types of dehydrogenase showed highest expression in tissues undergoing secondary wall synthesis. The UDP-glucuronate decarboxylase was purified as polypeptides of Mr 87 and 40 kDa. Peptide fingerprinting of the latter polypeptide identified it as a form of UDP-glucuronate decarboxylase and functionality was established by expressing the cognate cDNA in E. coli. Expression of 40 kDa polypeptide and its corresponding mRNA was also found to be highest in tissues associated with secondary wall formation.
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MESH Headings
- Amino Acid Sequence
- Blotting, Northern
- Blotting, Western
- Carboxy-Lyases/genetics
- Carboxy-Lyases/metabolism
- Cell Wall/genetics
- Cell Wall/metabolism
- Cells, Cultured
- Cloning, Molecular
- DNA, Complementary/chemistry
- DNA, Complementary/genetics
- Gene Expression Regulation, Enzymologic
- Gene Expression Regulation, Plant
- Molecular Sequence Data
- Plant Proteins/genetics
- Plant Proteins/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Nicotiana/cytology
- Nicotiana/genetics
- Nicotiana/metabolism
- Uridine Diphosphate Glucose/metabolism
- Uridine Diphosphate Glucose Dehydrogenase/genetics
- Uridine Diphosphate Glucose Dehydrogenase/isolation & purification
- Uridine Diphosphate Glucose Dehydrogenase/metabolism
- Uridine Diphosphate Xylose/metabolism
- Xylose/metabolism
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37
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Bar-Peled M, Griffith C, Ory J, Doering T. Biosynthesis of UDP-GlcA, a key metabolite for capsular polysaccharide synthesis in the pathogenic fungus Cryptococcus neoformans. Biochem J 2004; 381:131-6. [PMID: 15030319 PMCID: PMC1133770 DOI: 10.1042/bj20031075] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2003] [Revised: 03/18/2004] [Accepted: 03/19/2004] [Indexed: 11/17/2022]
Abstract
UDP-glucose dehydrogenase catalyses the conversion of UDP-glucose into UDP-GlcA, a critical precursor for glycan synthesis across evolution. We have cloned the gene encoding this important enzyme from the opportunistic pathogen Cryptococcus neoformans. In this fungus, UDP-GlcA is required for the synthesis of capsule polysaccharides, which in turn are essential for virulence. The gene was expressed in Escherichia coli and the 51.3-kDa recombinant protein from wild-type and five mutants was purified for analysis. The cryptococcal enzyme is strongly inhibited by UDP-xylose and NADH, has highest activity at pH 7.5 and demonstrates Km (app) values of 0.1 and 1.5 mM for NAD+ and UDP-glucose respectively. Its activity was significantly decreased by mutations in the putative sites of NAD+ and UDP-glucose binding. Unlike previously reported eukaryotic UDP-glucose dehydrogenases, which are hexamers, the cryptococcal enzyme is a dimer.
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Affiliation(s)
- Maor Bar-Peled
- *Complex Carbohydrate Research Center of the University of Georgia, 220 Riverbend Road, Athens, GA 30602-4712, U.S.A
| | - Cara L. Griffith
- †Department of Molecular Microbiology, Campus Box 8230, 660 South Euclid Avenue, St. Louis, MO 63110-1093, U.S.A
| | - Jeramia J. Ory
- †Department of Molecular Microbiology, Campus Box 8230, 660 South Euclid Avenue, St. Louis, MO 63110-1093, U.S.A
| | - Tamara L. Doering
- †Department of Molecular Microbiology, Campus Box 8230, 660 South Euclid Avenue, St. Louis, MO 63110-1093, U.S.A
- To whom correspondence should be addressed (e-mail )
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38
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Abstract
UDP-glucose dehydrogenase (UGDH) is the unique pathway enzyme furnishing in vertebrates UDP-glucuronate for numerous transferases. In this report, we have identified an NAD(+)-binding site within human UGDH by photoaffinity labeling with a specific probe, [(32)P]nicotinamide 2-azidoadenosine dinucleotide (2N(3) NAD(+)), and cassette mutagenesis. For this work, we have chemically synthesized a 1509-base pair gene encoding human UGDH and expressed it in Escherichia coli as a soluble protein. Photolabel-containing peptides were generated by photolysis followed by tryptic digestion and isolated using the phosphopeptide isolation kit. Photolabeling of these peptides was effectively prevented by the presence of NAD(+) during photolysis, demonstrating a selectivity of the photoprobe for the NAD(+)-binding site. Amino acid sequencing and compositional analysis identified the NAD(+)-binding site of UGDH as the region containing the sequence ICCIGAXYVGGPT, corresponding to Ile-7 through Thr-19 of the amino acid sequence of human UGDH. The unidentified residue, X, can be designated as a photolabeled Gly-13 because the sequences including the glycine residue in question have a complete identity with those of other UGDH species known. The importance of Gly-13 residue in the binding of NAD(+) was further examined with a G13E mutant by cassette mutagenesis. The mutagenesis at Gly-13 had no effects on the expression or stability of the mutant. Enzyme activity of the G13E point mutant was not measurable under normal assay conditions, suggesting an important role for the Gly-13 residue. No incorporation of [(32)P]2N(3)NAD(+) was observed for the G13E mutant. These results indicate that Gly-13 plays an important role for efficient binding of NAD(+) to human UGDH.
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Affiliation(s)
- Jae-Wan Huh
- Department of Biochemistry and Molecular Biology, University of Ulsan College of Medicine, Seoul 138-736, Korea
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39
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Sommer BJ, Barycki JJ, Simpson MA. Characterization of human UDP-glucose dehydrogenase. CYS-276 is required for the second of two successive oxidations. J Biol Chem 2004; 279:23590-6. [PMID: 15044486 DOI: 10.1074/jbc.m401928200] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
UDP-glucose dehydrogenase (UGDH) catalyzes two oxidations of UDP-glucose to yield UDP-glucuronic acid. Pathological overproduction of extracellular matrix components may be linked to the availability of UDP-glucuronic acid; therefore UGDH is an intriguing therapeutic target. Specific inhibition of human UGDH requires detailed knowledge of its catalytic mechanism, which has not been characterized. In this report, we have cloned, expressed, and affinity-purified the human enzyme and determined its steady state kinetic parameters. The human enzyme is active as a hexamer with values for Km and Vmax that agree well with those reported for a bovine homolog. We used crystal coordinates for Streptococcus pyogenes UGDH in complex with NAD+ cofactor and UDP-glucose substrate to generate a model of the enzyme active site. Based on this model, we selected Cys-276 and Lys-279 as likely catalytic residues and converted them to serine and alanine, respectively. Enzymatic activity of C276S and K279A point mutants was not measurable under normal assay conditions. Rate constants measured over several hours demonstrated that K279A continued to turn over, although 250-fold more slowly than wild type enzyme. C276S, however, performed only a single round of oxidation, indicating that it is essential for the second oxidation. This result is consistent with the postulated role of Cys-276 as a catalytic residue and supports its position in the reaction mechanism for the human enzyme. Lys-279 is likely to have a role in positioning active site residues and in maintaining the hexameric quaternary structure.
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Affiliation(s)
- Brandi J Sommer
- Department of Biochemistry, University of Nebraska, Lincoln, Nebraska 68588-0664, USA
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40
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Grangeasse C, Obadia B, Mijakovic I, Deutscher J, Cozzone AJ, Doublet P. Autophosphorylation of the Escherichia coli protein kinase Wzc regulates tyrosine phosphorylation of Ugd, a UDP-glucose dehydrogenase. J Biol Chem 2003; 278:39323-9. [PMID: 12851388 DOI: 10.1074/jbc.m305134200] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Autophosphorylation of protein-tyrosine kinases (PTKs) involved in exopolysaccharide and capsular polysaccharide biosynthesis and transport has been observed in a number of Gram-negative and Gram-positive bacteria. However, besides their own phosphorylation, little is known about other substrates targeted by these protein-modifying enzymes. Here, we present evidence that the protein-tyrosine kinase Wzc of Escherichia coli is able to phosphorylate an endogenous enzyme, UDP-glucose dehydrogenase (Ugd), which participates in the synthesis of the exopolysaccharide colanic acid. The process of phosphorylation of Ugd by Wzc was shown to be stimulated by previous autophosphorylation of Wzc on tyrosine 569. The phosphorylation of Ugd was demonstrated to actually occur on tyrosine and result in a significant increase of its dehydrogenase activity. In addition, the phosphotyrosine-protein phosphatase Wzb, which is known to effectively dephosphorylate Wzc, exhibited only a low effect, if any, on the dephosphorylation of Ugd. These data were related to the recent observation that two other UDP-glucose dehydrogenases have been also shown to be phosphorylated by a PTK in the Gram-positive bacterium Bacillus subtilis. Comparative analysis of the activities of PTKs from Gram-negative and Gram-positive bacteria showed that they are regulated by different mechanisms that involve, respectively, either the autophosphorylation of kinases or their interaction with a membrane protein activator.
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Affiliation(s)
- Christophe Grangeasse
- Institut de Biologie et Chimie des Protéines, CNRS, Université de Lyon, 69367 Lyon Cedex 07, France.
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41
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Hickery MS, Bayliss MT, Dudhia J, Lewthwaite JC, Edwards JCW, Pitsillides AA. Age-related changes in the response of human articular cartilage to IL-1alpha and transforming growth factor-beta (TGF-beta): chondrocytes exhibit a diminished sensitivity to TGF-beta. J Biol Chem 2003; 278:53063-71. [PMID: 13679381 DOI: 10.1074/jbc.m209632200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cartilage glycosaminoglycan (GAG) synthesis and composition, upon which its structural integrity depends, varies with age, is modified by anabolic and catabolic stimuli, and is regulated by UDP-glucuronate availability. However, how such stimuli, prototypically represented by transforming growth factor-beta1 (TGF-beta1) and IL-1alpha, modify GAG synthesis during aging of normal human articular cartilage is not known. Using explants, we show that chondroitin sulfate (CS):total GAG ratios decrease, whereas C6S:C4S ratios increase with cartilage maturation, and that chondrocytes in the cartilage mid-zone, but not the superficial or deep zones, exhibit uridine 5'-diphosphoglucose dehydrogenase (UDPGD) activity, which is also increased in mature cartilage. We also show that IL-1alpha treatment reduces both total GAG and CS synthesis, decreases C6S:C4S ratios (less C6S), but fails to modify chondrocyte UDPGD activity at all ages. On the other hand, TGF-beta1 increases total GAG synthesis in immature, but not mature, cartilage (stimulates CS but not non-CS), age-independently decreases C6S:C4S (more C4S), and increases chondrocyte UDPGD activity in a manner inversely correlated with age. Our findings show that TGF-beta1, but not IL-1alpha, modifies matrix synthesis such that its composition more closely resembles "less mature" articular cartilage. These effects of TGF-beta1, which appear to be restricted to periods of skeletal immaturity, are closely associated although not necessarily mechanistically linked with increases in chondrocyte UDPGD activity. The antianabolic effects of IL-1alpha are, on the other hand, likely to be independent of any direct modification in UDPGD activity and manifest equally in human cartilage of all ages.
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Affiliation(s)
- Mark S Hickery
- Department of Cell and Molecular Biology, Section for Connective Tissue Research, BMC C12, 221 84, Lund, Sweden
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42
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Mijakovic I, Poncet S, Boël G, Mazé A, Gillet S, Jamet E, Decottignies P, Grangeasse C, Doublet P, Le Maréchal P, Deutscher J. Transmembrane modulator-dependent bacterial tyrosine kinase activates UDP-glucose dehydrogenases. EMBO J 2003; 22:4709-18. [PMID: 12970183 PMCID: PMC212725 DOI: 10.1093/emboj/cdg458] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Protein-tyrosine kinases regulating bacterial exopolysaccharide synthesis autophosphorylate on tyrosines located in a conserved C-terminal region. So far no other substrates have been identified for these kinases. Here we demonstrate that Bacillus subtilis YwqD not only autophosphorylates at Tyr-228, but that it also phosphorylates the two UDP-glucose dehydrogenases (UDP-glucose DHs) YwqF and TuaD at a tyrosine residue. However, phosphorylation of YwqF and TuaD occurs only in the presence of the transmembrane protein YwqC. The presumed intracellular C-terminal part of YwqC (last 50 amino acids) seems to interact with the tyrosine-kinase and to allow YwqD-catalysed phosphorylation of the two UDP-glucose DHs, which are key enzymes for the synthesis of acidic polysaccharides. However, only when phosphorylated by YwqD do the two enzymes exhibit detectable UDP-glucose DH activity. Dephosphorylation of P-Tyr-YwqF and P-Tyr-TuaD by the P-Tyr-protein phosphatase YwqE switched off their UDP-glucose DH activity. YwqE, which is encoded by the fourth gene of the B.subtilis ywqCDEF operon, also dephosphorylates P-Tyr-YwqD.
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Affiliation(s)
- Ivan Mijakovic
- Laboratoire de Génétique des Microorganismes, CNRS/INRA/INA-PG UMR2585, 78850 Thiverval-Grignon, France
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43
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Abstract
For many years, a large body of circumstantial evidence supported the notion that the synovial membrane produced the hyaluronan-rich synovial fluid. A quantitative cytochemical technique for uridine-diphospho glucose dehydrogenase (UDPGD) activity established that fibroblast-like cells on the intimal surface of the synovial lining made a specific contribution to maintaining these glycosaminoglycan levels. Our studies have aimed to determine the mechanisms that control the attainment and persistence of this differentiated phenotype, and have recently focused on their appearance during joint cavity development in the embryonic limb; a process that is dependent upon skeletal movement. These in situ micro-biochemical studies have shown that cells bordering the presumptive joint cavity exhibit raised UDPGD activity, are associated with a matrix rich in hyaluronan and show immobilization-induced loss in such characteristics. Together with complimentary studies in adult joints, this suggests that mechanical stimuli promote the acquisition of this joint line-forming phenotype. For this reason our studies have attempted to identify the 'up-stream' mechano-dependent factors that control these events. Endothelial cells respond to mechanical stimuli by activating, via phosphorylation, mitogen activated protein kinase/extracellular signal-regulated kinase (MAPkinase/ERK). Using phospho-specific anti-ERK-1/2 antibodies we have shown that immunolabelling of developing limbs shows a clear joint line-selective activation during cavitation, with little if any labelling within neighbouring elements, and that this is abolished in immobilized limbs. In an attempt to facilitate the final mechanistic deciphering of these responses we have used an in vitro-based approach and found by Western blotting that active ERK-1/2 expression was increased in cultured articular surface cells following application of dynamic mechanical strain. Intriguingly, the use of a selective inhibitor (PD98059) of ERK activation by its classical activating kinase, Mek, to restrict such strain-induced increases, produced an enhanced strain-related increase in UDPGD mRNA expression. This suggests that mechano-dependent ERK activation serves a feedback regulatory role during differentiation of these cells. Whilst it is clear that these in vitro experiments serve a useful function, it is clear that they generally take little regard of the influence that might be provided by cell-cell and cell-matrix interactions within the developing limb's complex and dynamic environment and architecture. It is therefore imperative that we attempt to bridge the gap between the cell biology of such phenomena on the one hand, and the morphological approach to this same problem on the other.
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44
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Abstract
The Salmonella ugd gene is required for the incorporation of 4-aminoarabinose in the lipopolysaccharide and resistance to the antibiotic polymyxin B. Transcription of the ugd gene is induced by Fe3+ via the PmrA-PmrB two-component system and by low Mg2+ in a process that requires the PhoP-PhoQ two-component system, the PhoP-activated PmrD protein and the PmrA-PmrB system. Here, we establish that mutation of the tolB gene promotes ugd transcription independently of both the PhoP-PhoQ and PmrA-PmrB systems. This activation is mediated by the RcsC-YojN-RcsB phosphorelay and the RcsA protein, suggesting a role for ugd in capsule synthesis. Binding sites for the RcsB, PmrA and PhoP proteins were identified in the ugd promoter. Although the PmrA-PmrB and RcsC-YojN-RcsB systems promoted ugd transcription independently of the PhoP-PhoQ system under different environmental conditions, ugd expression inside macrophages was strictly dependent on PhoP-PhoQ, suggesting that low Mg2+ is a cue for the intracellular environment.
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Affiliation(s)
- Chakib Mouslim
- Department of Molecular Microbiology, Howard Hughes Medical Institute, Washington U niversity School of Medicine, 660 S. Euclid, St. Louis, MO 63110, USA
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45
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Abstract
Heparan sulphate proteoglycans (HSPG's) are cell surface proteins to which long, unbranched chains of modified sugars called heparan sulphate glycosaminoglycans have been covalently attached. Cell culture studies have demonstrated that HSPG's are required for optimal signal transduction by many secreted cell signaling molecules. Now, genetic studies in both Drosophila and vertebrates have illustrated that HSPG's play important roles in signal transduction in vivo and have also begun to reveal new roles for HSPG's in signaling events. In particular, HSPG's have been shown to be important in ligand sequestration of wingless, for the transport of the Hedgehog ligand, and for modulation of the Dpp morphogenetic gradient.
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Affiliation(s)
- Kent Nybakken
- Department of Genetics, Howard Hughes Medical Institute, Harvard Medical School, Boston, MA 02115-6092, USA
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46
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Abstract
In this study, UDP-glucose dehydrogenase has been purified to electrophoretic homogeneity from sugarcane (Saccharum spp. hybrid) culm. The enzyme had a pH optimum of 8.4 and a subunit molecular mass of 52 kDa. Specific activity of the final preparation was 2.17 micromol/min/mg protein. Apparent K(m) values of 18.7+/-0.75 and 72.2+/-2.7 microM were determined for UDP-glucose and NAD(+), respectively. The reaction catalyzed by UDP-glucose dehydrogenase was irreversible with two equivalents of NADH produced for each UDP-glucose oxidized. Stiochiometry was not altered in the presence of carbonyl-trapping reagents. With respect to UDP-glucose, UDP-glucuronic acid, and UDP-xylose were competitive inhibitors of UDP-glucose dehydrogenase with K(i) values of 292 and 17.1 microM, respectively. The kinetic data are consistent with a bi-uni-uni-bi substituted enzyme mechanism for sugarcane UDP-glucose dehydrogenase. Oxidation of the alternative nucleotide sugars CTP-glucose and TDP-glucose was observed with rates of 8 and 2%, respectively, compared to UDP-glucose. The nucleotide sugar ADP-glucose was not oxidized by UDP-glucose dehydrogenase. This is of significance as it demonstrates carbon, destined for starch synthesis in tissues that synthesize cytosolic AGP-glucose, will not be partitioned toward cell wall biosynthesis.
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Affiliation(s)
- William Turner
- Institute for Plant Biotechnology, University of Stellenbosch, Matieland, South Africa
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47
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Hwang HY, Horvitz HR. The Caenorhabditis elegans vulval morphogenesis gene sqv-4 encodes a UDP-glucose dehydrogenase that is temporally and spatially regulated. Proc Natl Acad Sci U S A 2002; 99:14224-9. [PMID: 12391315 PMCID: PMC137865 DOI: 10.1073/pnas.172522499] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The development of the Caenorhabditis elegans vulva requires the involution of epithelial cells and provides a model for organ morphogenesis. Mutations in C. elegans sqv (squashed vulva) genes affect both vulval morphogenesis and embryonic development. We found that sqv-4 encodes a protein similar to UDP-glucose dehydrogenases and showed that the SQV-4 protein specifically catalyzes the conversion of UDP-glucose to UDP-glucuronic acid, which is essential for the biosynthesis of chondroitin and heparan sulfate proteoglycans. SQV-4 is expressed in the vulva and in oocytes, among many other cells, and SQV-4 levels are dramatically increased in a specific subset of vulval cells during vulval morphogenesis. We propose that the regulation of UDP-glucuronic acid production in a specific subset of vulval cells helps determine the shape of the vulva.
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Affiliation(s)
- Ho-Yon Hwang
- Howard Hughes Medical Institute, Department of Biology, 68-425, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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48
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Abstract
Nucleotide sugar interconversion pathways represent a series of enzymatic reactions by which plants synthesize activated monosaccharides for the incorporation into cell wall material. Although biochemical aspects of these metabolic pathways are reasonably well understood, the identification and characterization of genes encoding nucleotide sugar interconversion enzymes is still in its infancy. Arabidopsis mutants defective in the activation and interconversion of specific monosaccharides have recently become available, and several genes in these pathways have been cloned and characterized. The sequence determination of the entire Arabidopsis genome offers a unique opportunity to identify candidate genes encoding nucleotide sugar interconversion enzymes via sequence comparisons to bacterial homologues. An evaluation of the Arabidopsis databases suggests that the majority of these enzymes are encoded by small gene families, and that most of these coding regions are transcribed. Although most of the putative proteins are predicted to be soluble, others contain N-terminal extensions encompassing a transmembrane domain. This suggests that some nucleotide sugar interconversion enzymes are targeted to an endomembrane system, such as the Golgi apparatus, where they may co-localize with glycosyltransferases in cell wall synthesis. The functions of the predicted coding regions can most likely be established via reverse genetic approaches and the expression of proteins in heterologous systems. The genetic characterization of nucleotide sugar interconversion enzymes has the potential to understand the regulation of these complex metabolic pathways and to permit the modification of cell wall material by changing the availability of monosaccharide precursors.
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Affiliation(s)
- W D Reiter
- Department of Molecular and Cell Biology, University of Connecticut, Storrs 06269-3125, USA.
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49
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Abstract
Nucleotide sugar interconversion pathways represent a series of enzymatic reactions by which plants synthesize activated monosaccharides for the incorporation into cell wall material. Although biochemical aspects of these metabolic pathways are reasonably well understood, the identification and characterization of genes encoding nucleotide sugar interconversion enzymes is still in its infancy. Arabidopsis mutants defective in the activation and interconversion of specific monosaccharides have recently become available, and several genes in these pathways have been cloned and characterized. The sequence determination of the entire Arabidopsis genome offers a unique opportunity to identify candidate genes encoding nucleotide sugar interconversion enzymes via sequence comparisons to bacterial homologues. An evaluation of the Arabidopsis databases suggests that the majority of these enzymes are encoded by small gene families, and that most of these coding regions are transcribed. Although most of the putative proteins are predicted to be soluble, others contain N-terminal extensions encompassing a transmembrane domain. This suggests that some nucleotide sugar interconversion enzymes are targeted to an endomembrane system, such as the Golgi apparatus, where they may co-localize with glycosyltransferases in cell wall synthesis. The functions of the predicted coding regions can most likely be established via reverse genetic approaches and the expression of proteins in heterologous systems. The genetic characterization of nucleotide sugar interconversion enzymes has the potential to understand the regulation of these complex metabolic pathways and to permit the modification of cell wall material by changing the availability of monosaccharide precursors.
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Affiliation(s)
- W D Reiter
- Department of Molecular and Cell Biology, University of Connecticut, Storrs 06269-3125, USA.
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50
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Abstract
Cardiac valve formation is a complex process that involves cell signaling events between the myocardial and endocardial layers of the heart across an elaborate extracellular matrix. These signals lead to marked morphogenetic movements and transdifferentiation of the endocardial cells at chamber boundaries. Here we identify the genetic defect in zebrafish jekyll mutants, which are deficient in the initiation of heart valve formation. The jekyll mutation disrupts a homolog of Drosophila Sugarless, a uridine 5'-diphosphate (UDP)-glucose dehydrogenase required for heparan sulfate, chondroitin sulfate, and hyaluronic acid production. The atrioventricular border cells do not differentiate from their neighbors in jekyll mutants, suggesting that Jekyll is required in a cell signaling event that establishes a boundary between the atrium and ventricle.
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Affiliation(s)
- E C Walsh
- Department of Biochemistry and Biophysics, Programs in Developmental Biology, Genetics and Human Genetics, University of California, San Francisco, CA 94143-0448, USA
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