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The rise and fall of anandamide: processes that control synthesis, degradation, and storage. Mol Cell Biochem 2021; 476:2753-2775. [PMID: 33713246 DOI: 10.1007/s11010-021-04121-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 02/25/2021] [Indexed: 12/16/2022]
Abstract
Anandamide is an endocannabinoid derived from arachidonic acid-containing membrane lipids and has numerous biological functions. Its effects are primarily mediated by the cannabinoid receptors CB1 and CB2, and the vanilloid TRPV1 receptor. Anandamide is known to be involved in sleeping and eating patterns as well as pleasure enhancement and pain relief. This manuscript provides a review of anandamide synthesis, degradation, and storage and hence the homeostasis of the anandamide signaling system.
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Shen Q, Lu C, Yang H, Ge MX, Xia WX, Kong QP, Li GH, Gu YH. Glycerophosphodiester phosphodiesterase 1 (GDE1) acts as a potential tumor suppressor and is a novel therapeutic target for non-mucin-producing colon adenocarcinoma. PeerJ 2020; 8:e8421. [PMID: 32095326 PMCID: PMC7020812 DOI: 10.7717/peerj.8421] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 12/17/2019] [Indexed: 12/24/2022] Open
Abstract
Colon adenocarcinoma (COAD) represents a major public health issue due to its high incidence and mortality. As different histological subtypes of COAD are related to various survival outcomes and different therapies, finding specific targets and treatments for different subtypes is one of the major demands of individual disease therapy. Interestingly, as these different subtypes show distinct metabolic profiles, it may be possible to find specific targets related to histological typing by targeting COAD metabolism. In this study, the differential expression patterns of metabolism-related genes between COAD (n = 289) and adjacent normal tissue (n = 41) were analyzed by one-way ANOVA. We then used weighted gene co-expression network analysis (WGCNA) to further identify metabolism-related gene connections. To determine the critical genes related to COAD metabolism, we obtained 2,114 significantly differentially expressed genes (DEGs) and 12 modules. Among them, we found the hub module to be significantly associated with histological typing, including non-mucin-producing colon adenocarcinoma and mucin-producing colon adenocarcinoma. Combining survival analysis, we identified glycerophosphodiester phosphodiesterase 1 (GDE1) as the most significant gene associated with histological typing and prognosis. This gene displayed significantly lower expression in COAD compared with normal tissues and was significantly correlated with the prognosis of non-mucin-producing colon adenocarcinoma (p = 0.0017). Taken together, our study showed that GDE1 exhibits considerable potential as a novel therapeutic target for non-mucin-producing colon adenocarcinoma.
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Affiliation(s)
- Qiu Shen
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China.,State Key Laboratory of Genetic Resources and Evolution/Key Laboratory of Healthy Aging Research of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Chao Lu
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China.,Department of Oncology, Jiangyin People's Hospital, Wuxi, Jiangsu, China
| | - Hua Yang
- The Third People's Hospital of Yunnan Province, Kunming, Yunnan, China
| | - Ming-Xia Ge
- State Key Laboratory of Genetic Resources and Evolution/Key Laboratory of Healthy Aging Research of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Wang-Xiao Xia
- State Key Laboratory of Genetic Resources and Evolution/Key Laboratory of Healthy Aging Research of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Qing-Peng Kong
- State Key Laboratory of Genetic Resources and Evolution/Key Laboratory of Healthy Aging Research of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Gong-Hua Li
- State Key Laboratory of Genetic Resources and Evolution/Key Laboratory of Healthy Aging Research of Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan, China
| | - Yan-Hong Gu
- Department of Oncology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu, China
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3
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Abstract
Bacterial glycerophosphodiester phosphodiesterases (GP-PDEs), GlpQ and UgpQ, are well-characterized periplasmic and cytosolic proteins that play critical roles in the hydrolysis of deacylated glycerophospholipids to glycerol phosphate and alcohol, which are utilized as major sources of carbon and phosphate. In contrast, two novel mammalian GP-PDEs, GDE1/MIR16 and GDE3, were recently identified, and were shown to be involved in several physiological functions. GDE1/MIR16 was identified as a membrane protein interacting with RGS16, a regulator of G protein signaling, and found to hydrolyze glycerophosphoinositol preferentially. We have found that expression of GDE3 is significantly up-regulated during osteoblast differentiation and is involved in morphological changes of cells. Furthermore, five mammalian GP-PDEs were virtually identified, and very recent studies indicate that retinoic acid-induced expression of GDE2 plays essential roles in neuronal differentiation and neurite outgrowth. Thus mammalian GP-PDEs are likely to be important in controlling numerous cellular events, indicating that the GP-PDE superfamily in mammals might be a pharmacological target in the future.
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Affiliation(s)
- Noriyuki Yanaka
- Department of Molecular and Applied Bioscience, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, Japan.
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4
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Corda D, Mosca MG, Ohshima N, Grauso L, Yanaka N, Mariggiò S. The emerging physiological roles of the glycerophosphodiesterase family. FEBS J 2014; 281:998-1016. [PMID: 24373430 DOI: 10.1111/febs.12699] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 12/12/2013] [Accepted: 12/19/2013] [Indexed: 01/21/2023]
Abstract
The glycerophosphodiester phosphodiesterases are evolutionarily conserved proteins that have been linked to several patho/physiological functions, comprising bacterial pathogenicity and mammalian cell proliferation or differentiation. The bacterial enzymes do not show preferential substrate selectivities among the glycerophosphodiesters, and they are mainly dedicated to glycerophosphodiester hydrolysis, producing glycerophosphate and alcohols as the building blocks that are required for bacterial biosynthetic pathways. In some cases, this enzymatic activity has been demonstrated to contribute to bacterial pathogenicity, such as with Hemophilus influenzae. Mammalian glyerophosphodiesterases have high substrate specificities, even if the number of potential physiological substrates is continuously increasing. Some of these mammalian enzymes have been directly linked to cell differentiation, such as GDE2, which triggers motor neuron differentiation, and GDE3, the enzymatic activity of which is necessary and sufficient to induce osteoblast differentiation. Instead, GDE5 has been shown to inhibit skeletal muscle development independent of its enzymatic activity.
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Affiliation(s)
- Daniela Corda
- Institute of Protein Biochemistry, National Research Council, Naples, Italy
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5
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PRAF2 stimulates cell proliferation and migration and predicts poor prognosis in neuroblastoma. Int J Oncol 2013; 42:1408-16. [PMID: 23440329 DOI: 10.3892/ijo.2013.1836] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 09/07/2012] [Indexed: 11/05/2022] Open
Abstract
Prenylated Rab acceptor 1 domain family, member 2 (PRAF2) is a novel 19-kDa protein with four transmembrane-spanning domains that belongs to the PRAF protein family. Neuroblastoma (NB) is the most common malignant extracranial solid tumor of childhood that originates in primitive cells of the developing sympathetic nervous system. We investigated the correlation of PRAF2 mRNA expression to NB clinical and genetic parameters using Affymetrix expression analysis of a series of 88 NB tumors and examined the functional role of PRAF2 in an NB cell line using RNA interference. We found that high PRAF2 expression is significantly correlated to several unfavorable NB characteristics: MYCN amplification, high age at diagnosis, poor outcome and high INSS stage. The shRNA-mediated PRAF2 downregulation in the SK-N-SH NB cell line resulted in decreased cellular proliferation, migration and matrix-attachment. These findings were confirmed in NB patient tumor samples, where high PRAF2 expression is significantly correlated to bone and bone marrow metastasis, the main cause of death in NB patients. The present study shows that PRAF2 plays an essential role in NB tumorigenesis and metastasis.
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6
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Okazaki Y, Ohshima N, Yoshizawa I, Kamei Y, Mariggiò S, Okamoto K, Maeda M, Nogusa Y, Fujioka Y, Izumi T, Ogawa Y, Shiro Y, Wada M, Kato N, Corda D, Yanaka N. A novel glycerophosphodiester phosphodiesterase, GDE5, controls skeletal muscle development via a non-enzymatic mechanism. J Biol Chem 2010; 285:27652-63. [PMID: 20576599 PMCID: PMC2934633 DOI: 10.1074/jbc.m110.106708] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 06/08/2010] [Indexed: 11/06/2022] Open
Abstract
Mammalian glycerophosphodiester phosphodiesterases (GP-PDEs) have been identified recently and shown to be implicated in several physiological functions. This study isolated a novel GP-PDE, GDE5, and showed that GDE5 selectively hydrolyzes glycerophosphocholine (GroPCho) and controls skeletal muscle development. We show that GDE5 expression was reduced in atrophied skeletal muscles in mice and that decreasing GDE5 abundance promoted myoblastic differentiation, suggesting that decreased GDE5 expression has a counter-regulatory effect on the progression of skeletal muscle atrophy. Forced expression of full-length GDE5 in cultured myoblasts suppressed myogenic differentiation. Unexpectedly, a truncated GDE5 construct (GDE5DeltaC471), which contained a GP-PDE sequence identified in other GP-PDEs but lacked GroPCho phosphodiesterase activity, showed a similar inhibitory effect. Furthermore, transgenic mice specifically expressing GDE5DeltaC471 in skeletal muscle showed less skeletal muscle mass, especially type II fiber-rich muscle. These results indicate that GDE5 negatively regulates skeletal muscle development even without GroPCho phosphodiesterase activity, providing novel insight into the biological significance of mammalian GP-PDE function in a non-enzymatic mechanism.
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MESH Headings
- Amino Acid Sequence
- Animals
- Cell Differentiation
- Cell Line
- Cloning, Molecular
- Computational Biology
- DNA, Complementary/genetics
- Gene Expression Regulation, Enzymologic
- Humans
- Mice
- Mice, Transgenic
- Molecular Sequence Data
- Muscle Development
- Muscle Fibers, Skeletal/cytology
- Muscle Fibers, Skeletal/metabolism
- Muscle, Skeletal/cytology
- Muscle, Skeletal/enzymology
- Muscle, Skeletal/growth & development
- Muscular Atrophy/enzymology
- Muscular Atrophy/genetics
- Phosphoric Diester Hydrolases/chemistry
- Phosphoric Diester Hydrolases/genetics
- Phosphoric Diester Hydrolases/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
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Affiliation(s)
- Yuri Okazaki
- From the Department of Molecular and Applied Bioscience, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
| | - Noriyasu Ohshima
- the Department of Biochemistry, Gunma University Graduate School of Medicine, Gunma 371-8511, Japan
| | - Ikumi Yoshizawa
- From the Department of Molecular and Applied Bioscience, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
| | - Yasutomi Kamei
- the Department of Molecular Medicine and Metabolism, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Stefania Mariggiò
- the Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Santa Maria Imbaro, 66030 Chieti, Italy
- the Institute of Protein Biochemistry, National Research Council, 80131 Naples, Italy
| | - Keiko Okamoto
- From the Department of Molecular and Applied Bioscience, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
| | - Masahiro Maeda
- From the Department of Molecular and Applied Bioscience, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
| | - Yoshihito Nogusa
- From the Department of Molecular and Applied Bioscience, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
| | - Yuichiro Fujioka
- From the Department of Molecular and Applied Bioscience, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
| | - Takashi Izumi
- the Department of Biochemistry, Gunma University Graduate School of Medicine, Gunma 371-8511, Japan
| | - Yoshihiro Ogawa
- the Department of Molecular Medicine and Metabolism, Medical Research Institute, Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Yoshitsugu Shiro
- the RIKEN SPring-8 Center, Harima Institute, Hongo 679-5148, Japan, and
| | - Masanobu Wada
- the Department of Human Sciences, Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima 739-8521, Japan
| | - Norihisa Kato
- From the Department of Molecular and Applied Bioscience, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
| | - Daniela Corda
- the Department of Cell Biology and Oncology, Consorzio Mario Negri Sud, Santa Maria Imbaro, 66030 Chieti, Italy
- the Institute of Protein Biochemistry, National Research Council, 80131 Naples, Italy
| | - Noriyuki Yanaka
- From the Department of Molecular and Applied Bioscience, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima 739-8528, Japan
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7
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Ueda N, Tsuboi K, Uyama T. Enzymological studies on the biosynthesis of N-acylethanolamines. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1801:1274-85. [PMID: 20736084 DOI: 10.1016/j.bbalip.2010.08.010] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Revised: 08/10/2010] [Accepted: 08/17/2010] [Indexed: 11/28/2022]
Abstract
Ethanolamides of different long-chain fatty acids constitute a class of endogenous lipid molecules generally called N-acylethanolamines (NAEs). They contain N-arachidonoylethanolamine (anandamide), N-palmitoylethanolamine, and N-oleoylethanolamine, which receive considerable attention because of their actions as an endogenous cannabinoid receptor ligand (endocannabinoid), an anti-inflammatory substance, and an appetite-suppressing substance, respectively. Identification of their biosynthetic routes in animal tissues and molecular characterization of the enzymes involved are essential for better understanding of physiological importance of NAEs as well as development of enzyme inhibitors as possible therapeutic drugs. In the classical "transacylation-phosphodiesterase pathway", NAEs are formed from glycerophospholipids via N-acylphosphatidylethanolamine (NAPE), an unusual derivative of phosphatidylethanolamine with a third acyl chain attached to the amino group, by sequential catalyses by Ca(2+)-dependent N-acyltransferase and NAPE-hydrolyzing phospholipase D. However, recent studies reveal that NAE-generating pathways are more complex than presumed before. In this review article, we will focus on recent findings regarding mammalian enzymes that are involved or might be involved in the biosynthesis of NAEs.
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Affiliation(s)
- Natsuo Ueda
- Department of Biochemistry, Kagawa University School of Medicine, 1750-1 Ikenobe, Miki, Kagawa 761-0793, Japan.
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8
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Borsics T, Lundberg E, Geerts D, Koomoa DLT, Koster J, Wester K, Bachmann AS. Subcellular distribution and expression of prenylated Rab acceptor 1 domain family, member 2 (PRAF2) in malignant glioma: Influence on cell survival and migration. Cancer Sci 2010; 101:1624-31. [PMID: 20412121 PMCID: PMC11158841 DOI: 10.1111/j.1349-7006.2010.01570.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Our previous studies revealed that the expression of the 19-kDa protein prenylated Rab acceptor 1 domain family, member 2 (PRAF2) is elevated in cancer tissues of the breast, colon, lung, and ovary, when compared to noncancerous tissues of paired samples. PRAF2 mRNA expression also correlated with several genetic and clinical features and is a candidate prognostic marker in the pediatric cancer neuroblastoma. The PRAF2-related proteins, PRAF1 and PRAF3, play multiple roles in cellular processes, including endo/exocytic vesicle trafficking and glutamate uptake. PRAF2 shares a high sequence homology with these family members, but its function remains unknown. In this study, we examined PRAF2 mRNA and protein expression in 20 different human cancer types using Affymetrix microarray and human tissue microarray (TMA) analyses, respectively. In addition, we investigated the subcellular distribution of PRAF2 by immunofluorescence microscopy and cell fractionation studies. PRAF2 mRNA and protein expression was elevated in several cancer tissues with highest levels in malignant glioma. At the molecular level, we detected native PRAF2 in small, vesicle-like structures throughout the cytoplasm as well as in and around cell nuclei of U-87 malignant glioma cells. We further found that monomeric and dimeric forms of PRAF2 are associated with different cell compartments, suggesting possible functional differences. Importantly, PRAF2 down-regulation by RNA interference significantly reduced the cell viability, migration, and invasiveness of U-87 cells. This study shows that PRAF2 expression is elevated in various tumors with exceptionally high expression in malignant gliomas, and PRAF2 therefore presents a candidate molecular target for therapeutic intervention.
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Affiliation(s)
- Tamás Borsics
- Cancer Research Center of Hawaii, University of Hawaii at Manoa, Honolulu, Hawaii, USA
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9
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Chang PA, Shao HB, Long DX, Sun Q, Wu YJ. Isolation, characterization and molecular 3D model of human GDE4, a novel membrane protein containing glycerophosphodiester phosphodiesterase domain. Mol Membr Biol 2009; 25:557-66. [PMID: 18991142 DOI: 10.1080/09687680802537605] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
As a transmembrane protein family, glycerophosphodiester phosphodiesterase (GDPD/GDE) catalyzes the hydrolysis of deacylated glycerophospholipids to glycerol phosphate and alcohol. To date, seven mammalian GDEs have been virtually cloned or predicted by bioinformatics analysis, however, GDE4 has not been molecular isolated and characterized in mammal. Here we report molecular cloning of human GDE4 encoding cDNA sequence, which is 945 base pairs long encoding a 314-amino acid protein with 2 transmembrane regions and a GDE motif. The human GDE1 gene is located on chromosome 19q22 and contains ten exons and nine introns. A molecular 3-D model provides the first structural information of human GDE4 and suggests a triose-phosphate-isomerase barrel core as typically found in bacterial GDPDs. Furthermore, a model of the putative catalytic residues highlights that the individual core residues Glu72, Asp74, and His87 are crucial to maintaining GDE4 catalytic activity. Western blotting shows that human GDE4 is a 36 kDa protein. Subcellular localization of GDE4 tagged with enhanced green fluorescence protein is in the cytoplasm, especially accumulated in the perinuclear region and the cell periphery. Moreover, over-expression of GDE4 did not induce neurite formation or change cell morphology. These results indicate GDE4 protein is a member of the GDE family and suggest it may play different roles from other members of GDE family.
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Affiliation(s)
- Ping A Chang
- Key Laboratory of Molecular Biology, College of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing, PR China.
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10
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Shi L, Liu JF, An XM, Liang DC. Crystal structure of glycerophosphodiester phosphodiesterase (GDPD) from Thermoanaerobacter tengcongensis, a metal ion-dependent enzyme: insight into the catalytic mechanism. Proteins 2008; 72:280-8. [PMID: 18214974 DOI: 10.1002/prot.21921] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Glycerophosphodiester phosphodiesterase (GDPD; EC 3.1.4.46) catalyzes the hydrolysis of a glycerophosphodiester to an alcohol and glycerol 3-phosphate in glycerol metabolism. It has an important role in the synthesis of a variety of products that participate in many biochemical pathways. We report the crystal structure of the Thermoanaerobacter tengcongensis GDPD (ttGDPD) at 1.91 A resolution, with a calcium ion and glycerol as a substrate mimic coordinated at this calcium ion (PDB entry 2pz0). The ttGDPD dimer with an intermolecular disulfide bridge and two hydrogen bonds is considered as the potential functional unit. We used site-directed mutagenesis to characterize ttGDPD as a metal ion-dependent enzyme, identified a cluster of residues involved in substrate binding and the catalytic reaction, and we propose a possible general acid-base catalytic mechanism for ttGDPD. Superposing the active site with the homologous structure GDPD from Agrobacterium tumefaciens (PDB entry 1zcc), which binds a sulfate ion in the active site, the sulfate ion can represent the phosphate moiety of the substrate, simulating the binding mode of the true substrate of GDPD.
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Affiliation(s)
- Liang Shi
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, People's Republic of China
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11
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Geerts D, Wallick CJ, Koomoa DLT, Koster J, Versteeg R, Go RCV, Bachmann AS. Expression of prenylated Rab acceptor 1 domain family, member 2 (PRAF2) in neuroblastoma: correlation with clinical features, cellular localization, and cerulenin-mediated apoptosis regulation. Clin Cancer Res 2008; 13:6312-9. [PMID: 17975142 DOI: 10.1158/1078-0432.ccr-07-0829] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE Prenylated Rab acceptor 1 domain family, member 2 (PRAF2) is a novel 19-kDa protein that has recently been implicated in human cancer. In the present study, we analyzed for the first time PRAF2 mRNA expression in a large set of human tumors. The high expression in neuroblastic tumors prompted us to analyze PRAF2 expression correlations with genetic and clinical features of these tumors. In addition, we determined the localization of PRAF2 protein in neuroblastoma cells and studied its regulation in apoptosis. EXPERIMENTAL DESIGN Affymetrix microarray analysis was done with a set of 41 different tumor types (1,426 samples) in the public domain, a set of three different neuroblastic tumor types (110 samples), and a panel of 25 neuroblastoma cell lines. The subcellular localization of endogenous PRAF2 in neuroblastoma cells was identified by immunofluorescence microscopy and apoptosis detected by Annexin V staining and poly(ADP-ribose) polymerase cleavage. RESULTS PRAF2 mRNA was detected in 970 of 1,426 samples in the public data set. All 110 neuroblastic tumors expressed PRAF2 at higher levels than any other tumor examined. Importantly, PRAF2 expression levels significantly correlated with the following clinical features: patient age at diagnosis (P = 6.19 x 10(-5)), survival (P = 1.32 x 10(-3)), International Neuroblastoma Staging System stage (P = 2.86 x 10(-4)), and MYCN amplification (P = 3.74 x 10(-3)). PRAF2 localized in bright cytoplasmic punctae and protein levels increased in neuroblastoma cells that underwent cerulenin-induced apoptosis. CONCLUSIONS Elevated PRAF2 expression levels correlated with unfavorable genetic and clinical features, suggesting PRAF2 as a candidate prognostic marker of neuroblastoma.
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Affiliation(s)
- Dirk Geerts
- Cancer Research Center of Hawaii, University of Hawaii at Manoa, Honolulu, HI 96813, USA
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