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Zhou C, Hu Z, Liu X, Wang Y, Wei S, Liu Z. Disruption of the peripheral biological clock may play a role in sleep deprivation-induced dysregulation of lipid metabolism in both the daytime and nighttime phases. Biochim Biophys Acta Mol Cell Biol Lipids 2024; 1869:159530. [PMID: 38964437 DOI: 10.1016/j.bbalip.2024.159530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 06/14/2024] [Accepted: 07/02/2024] [Indexed: 07/06/2024]
Abstract
STUDY OBJECTIVES This study aimed to examine the effect of sleep deprivation (SD) on lipid metabolism or lipid metabolism regulation in the liver and white adipose tissue (WAT) during the light and dark phases and explored the possible mechanisms underlying the diurnal effect of SD on lipid metabolism associated with clock genes. METHODS Male C57BL/6J mice aged 2 months were deprived of sleep daily for 20 h for ten consecutive days with weakly forced locomotion. The body weights and food consumption levels of the SD and control mice were recorded, and the mice were then sacrificed at ZT (zeitgeber time) 2 and ZT 14. The peripheral clock genes, enzymes involved in fat synthesis and catabolism in the WAT, and melatonin signalling pathway-mediated lipid metabolism in the liver were assessed. Untargeted metabolomics and tandem mass tag (TMT) proteomics were used to identify differential lipid metabolism pathways in the liver. RESULTS Bodyweight gain and daily food consumption were dramatically elevated after SD. Profound disruptions in the diurnal regulation of the hepatic peripheral clock and enzymes involved in fat synthesis and catabolism in the WAT were observed, with a strong emphasis on hepatic lipid metabolic pathways, while melatonin signalling pathway-mediated lipid metabolism exhibited moderate changes. CONCLUSIONS In mice, ten consecutive days of SD increased body weight gain and daily food consumption. In addition, SD profoundly disrupted lipid metabolism in the WAT and liver during the light and dark periods. These diurnal changes may be related to disorders of the peripheral biological clock.
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Affiliation(s)
- Chufan Zhou
- Yancheng No.1 People's Hospital, Affiliated Hospital of Medical School, Nanjing University, Yancheng, China; Nanjing Children's Hospital, Clinical Teaching Hospital of Medical School, Nanjing University, Nanjing, China
| | - Ziping Hu
- Yancheng No.1 People's Hospital, Affiliated Hospital of Medical School, Nanjing University, Yancheng, China.
| | - Xuan Liu
- Department of Child, Adolescent and Women's Health, School of Public Health, Capital Medical University, Beijing, China
| | - Yuefan Wang
- Department of Child, Adolescent and Women's Health, School of Public Health, Capital Medical University, Beijing, China
| | - Shougang Wei
- Department of Child, Adolescent and Women's Health, School of Public Health, Capital Medical University, Beijing, China
| | - Zhifeng Liu
- Nanjing Children's Hospital, Clinical Teaching Hospital of Medical School, Nanjing University, Nanjing, China.
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Lulić AM, Katalinić M. The PNPLA family of enzymes: characterisation and biological role. Arh Hig Rada Toksikol 2023; 74:75-89. [PMID: 37357879 PMCID: PMC10291501 DOI: 10.2478/aiht-2023-74-3723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/01/2023] [Accepted: 05/01/2023] [Indexed: 06/27/2023] Open
Abstract
This paper brings a brief review of the human patatin-like phospholipase domain-containing protein (PNPLA) family. Even though it consists of only nine members, their physiological roles and mechanisms of their catalytic activity are not fully understood. However, the results of a number of knock-out and gain- or loss-of-function research models suggest that these enzymes have an important role in maintaining the homeostasis and integrity of organelle membranes, in cell growth, signalling, cell death, and the metabolism of lipids such as triacylglycerol, phospholipids, ceramides, and retinyl esters. Research has also revealed a connection between PNPLA family member mutations or irregular catalytic activity and the development of various diseases. Here we summarise important findings published so far and discuss their structure, localisation in the cell, distribution in the tissues, specificity for substrates, and their potential physiological role, especially in view of their potential as drug targets.
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Affiliation(s)
- Ana-Marija Lulić
- Institute for Medical Research and Occupational Health, Biochemistry and Organic Analytical Chemistry Unit, Zagreb, Croatia
| | - Maja Katalinić
- Institute for Medical Research and Occupational Health, Biochemistry and Organic Analytical Chemistry Unit, Zagreb, Croatia
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3
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The phospholipase A 2 superfamily as a central hub of bioactive lipids and beyond. Pharmacol Ther 2023; 244:108382. [PMID: 36918102 DOI: 10.1016/j.pharmthera.2023.108382] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/06/2023] [Accepted: 03/07/2023] [Indexed: 03/13/2023]
Abstract
In essence, "phospholipase A2" (PLA2) means a group of enzymes that release fatty acids and lysophospholipids by hydrolyzing the sn-2 position of glycerophospholipids. To date, more than 50 enzymes possessing PLA2 or related lipid-metabolizing activities have been identified in mammals, and these are subdivided into several families in terms of their structures, catalytic mechanisms, tissue/cellular localizations, and evolutionary relationships. From a general viewpoint, the PLA2 superfamily has mainly been implicated in signal transduction, driving the production of a wide variety of bioactive lipid mediators. However, a growing body of evidence indicates that PLA2s also contribute to phospholipid remodeling or recycling for membrane homeostasis, fatty acid β-oxidation for energy production, and barrier lipid formation on the body surface. Accordingly, PLA2 enzymes are considered one of the key regulators of a broad range of lipid metabolism, and perturbation of specific PLA2-driven lipid pathways often disrupts tissue and cellular homeostasis and may be associated with a variety of diseases. This review covers current understanding of the physiological functions of the PLA2 superfamily, focusing particularly on the two major intracellular PLA2 families (Ca2+-dependent cytosolic PLA2s and Ca2+-independent patatin-like PLA2s) as well as other PLA2 families, based on studies using gene-manipulated mice and human diseases in combination with comprehensive lipidomics.
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Harada S, Taketomi Y, Aiba T, Kawaguchi M, Hirabayashi T, Uranbileg B, Kurano M, Yatomi Y, Murakami M. The Lysophospholipase PNPLA7 Controls Hepatic Choline and Methionine Metabolism. Biomolecules 2023; 13:biom13030471. [PMID: 36979406 PMCID: PMC10046082 DOI: 10.3390/biom13030471] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 02/28/2023] [Accepted: 02/28/2023] [Indexed: 03/08/2023] Open
Abstract
The in vivo roles of lysophospholipase, which cleaves a fatty acyl ester of lysophospholipid, remained unclear. Recently, we have unraveled a previously unrecognized physiological role of the lysophospholipase PNPLA7, a member of the Ca2+-independent phospholipase A2 (iPLA2) family, as a key regulator of the production of glycerophosphocholine (GPC), a precursor of endogenous choline, whose methyl groups are preferentially fluxed into the methionine cycle in the liver. PNPLA7 deficiency in mice markedly decreases hepatic GPC, choline, and several metabolites related to choline/methionine metabolism, leading to various symptoms reminiscent of methionine shortage. Overall metabolic alterations in the liver of Pnpla7-null mice in vivo largely recapitulate those in methionine-deprived hepatocytes in vitro. Reduction of the methyl donor S-adenosylmethionine (SAM) after methionine deprivation decreases the methylation of the PNPLA7 gene promoter, relieves PNPLA7 expression, and thereby increases GPC and choline levels, likely as a compensatory adaptation. In line with the view that SAM prevents the development of liver cancer, the expression of PNPLA7, as well as several enzymes in the choline/methionine metabolism, is reduced in human hepatocellular carcinoma. These findings uncover an unexplored role of a lysophospholipase in hepatic phospholipid catabolism coupled with choline/methionine metabolism.
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Affiliation(s)
- Sayaka Harada
- Laboratory of Microenvironmental and Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Yoshitaka Taketomi
- Laboratory of Microenvironmental and Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Toshiki Aiba
- Department of Radiation Effects Research, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Mai Kawaguchi
- Laboratory of Microenvironmental and Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
- Laboratory of Biomembrane, Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Tetsuya Hirabayashi
- Laboratory of Biomembrane, Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Baasanjav Uranbileg
- Department of Clinical Laboratory Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Makoto Kurano
- Department of Clinical Laboratory Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Yutaka Yatomi
- Department of Clinical Laboratory Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Makoto Murakami
- Laboratory of Microenvironmental and Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
- Correspondence: ; Tel.: +81-3-5841-1431
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Hirabayashi T, Kawaguchi M, Harada S, Mouri M, Takamiya R, Miki Y, Sato H, Taketomi Y, Yokoyama K, Kobayashi T, Tokuoka SM, Kita Y, Yoda E, Hara S, Mikami K, Nishito Y, Kikuchi N, Nakata R, Kaneko M, Kiyonari H, Kasahara K, Aiba T, Ikeda K, Soga T, Kurano M, Yatomi Y, Murakami M. Hepatic phosphatidylcholine catabolism driven by PNPLA7 and PNPLA8 supplies endogenous choline to replenish the methionine cycle with methyl groups. Cell Rep 2023; 42:111940. [PMID: 36719796 DOI: 10.1016/j.celrep.2022.111940] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 11/10/2022] [Accepted: 12/19/2022] [Indexed: 01/31/2023] Open
Abstract
Choline supplies methyl groups for regeneration of methionine and the methyl donor S-adenosylmethionine in the liver. Here, we report that the catabolism of membrane phosphatidylcholine (PC) into water-soluble glycerophosphocholine (GPC) by the phospholipase/lysophospholipase PNPLA8-PNPLA7 axis enables endogenous choline stored in hepatic PC to be utilized in methyl metabolism. PNPLA7-deficient mice show marked decreases in hepatic GPC, choline, and several metabolites related to the methionine cycle, accompanied by various signs of methionine insufficiency, including growth retardation, hypoglycemia, hypolipidemia, increased energy consumption, reduced adiposity, increased fibroblast growth factor 21 (FGF21), and an altered histone/DNA methylation landscape. Moreover, PNPLA8-deficient mice recapitulate most of these phenotypes. In contrast to wild-type mice fed a methionine/choline-deficient diet, both knockout strains display decreased hepatic triglyceride, likely via reductions of lipogenesis and GPC-derived glycerol flux. Collectively, our findings highlight the biological importance of phospholipid catabolism driven by PNPLA8/PNPLA7 in methyl group flux and triglyceride synthesis in the liver.
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Affiliation(s)
- Tetsuya Hirabayashi
- Laboratory of Biomembrane, Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Lipid Metabolism Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan.
| | - Mai Kawaguchi
- Laboratory of Biomembrane, Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Sayaka Harada
- Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Misa Mouri
- Lipid Metabolism Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Department of Biology, Faculty of Science, Ochanomizu University, Tokyo 112-8610, Japan
| | - Rina Takamiya
- Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Yoshimi Miki
- Lipid Metabolism Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Hiroyasu Sato
- Lipid Metabolism Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Yoshitaka Taketomi
- Lipid Metabolism Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Kohei Yokoyama
- Laboratory of Biomembrane, Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Lipid Metabolism Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Tetsuyuki Kobayashi
- Department of Biology, Faculty of Science, Ochanomizu University, Tokyo 112-8610, Japan
| | - Suzumi M Tokuoka
- Department of Lipidomics, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yoshihiro Kita
- Department of Lipidomics, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan; Life Sciences Core Facility, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Emiko Yoda
- Division of Health Chemistry, Department of Healthcare and Regulatory Sciences, School of Pharmacy, Showa University, Tokyo 142-8555, Japan
| | - Shuntaro Hara
- Division of Health Chemistry, Department of Healthcare and Regulatory Sciences, School of Pharmacy, Showa University, Tokyo 142-8555, Japan
| | - Kyohei Mikami
- Center for Basic Technology Research, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Yasumasa Nishito
- Center for Basic Technology Research, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Norihito Kikuchi
- Laboratory of Biomembrane, Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Rieko Nakata
- Department of Food Science and Nutrition, Nara Women's University, Nara, 630-8506, Japan
| | - Mari Kaneko
- Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Biosystems Dynamics Research, Kobe, Hyogo 650-0047, Japan
| | - Hiroshi Kiyonari
- Laboratory for Animal Resources and Genetic Engineering, RIKEN Center for Biosystems Dynamics Research, Kobe, Hyogo 650-0047, Japan
| | - Kohji Kasahara
- Laboratory of Biomembrane, Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Toshiki Aiba
- Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan; Department of Radiation Effects Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba 263-8555, Japan
| | - Kazutaka Ikeda
- Kazusa DNA Research Institute, Kisarazu, Chiba 292-0818, Japan
| | - Tomoyoshi Soga
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Yamagata 997-0052, Japan
| | - Makoto Kurano
- Department of Clinical Laboratory Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Yutaka Yatomi
- Department of Clinical Laboratory Medicine, The University of Tokyo, Tokyo 113-8655, Japan
| | - Makoto Murakami
- Lipid Metabolism Project, Department of Advanced Science for Biomolecules, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan; Laboratory of Microenvironmental Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo 113-8655, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Tokyo 100-0004, Japan.
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Miš K, Lulić AM, Marš T, Pirkmajer S, Katalinić M. Insulin, dibutyryl-cAMP, and glucose modulate expression of patatin-like domain containing protein 7 in cultured human myotubes. Front Endocrinol (Lausanne) 2023; 14:1139303. [PMID: 37033214 PMCID: PMC10073714 DOI: 10.3389/fendo.2023.1139303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 03/06/2023] [Indexed: 04/11/2023] Open
Abstract
Expression of patatin-like phospholipase domain containing protein 7 (PNPLA7), also known as neuropathy target esterase-related esterase (NRE), a lysophospholipase, increases with fasting and decreases with feeding in mouse skeletal muscle, indicating it is regulated by insulin, counterregulatory hormones, such as glucocorticoids and catecholamines, and/or nutrients. In cultured mouse adipocytes insulin reduces Pnpla7 expression, underscoring the possibility that insulin regulates PNPLA7 in skeletal muscle. The first aim of this study was to establish whether PNPLA7 is functionally expressed in cultured human skeletal muscle cells. The second aim was to determine whether PNPLA7 is regulated by insulin, glucocorticoids, cAMP/protein kinase A pathway, and/or glucose. Cultured human skeletal muscle cells expressed PNPLA7 mRNA and protein. Gene silencing of PNPLA7 in myoblasts reduced the phosphorylation of 70 kDa ribosomal protein S6 kinase and ribosomal protein S6 as well as the abundance of α1-subunit of Na+,K+-ATPase and acetyl-CoA carboxylase, indirectly suggesting that PNPLA7 is functionally important. In myotubes, insulin suppressed PNPLA7 mRNA at 1 g/L glucose, but not at low (0.5 g/L) or high (4.5 g/L) concentrations. Treatment with synthetic glucocorticoid dexamethasone and activator of adenylyl cyclase forskolin had no effect on PNPLA7 regardless of glucose concentration, while dibutyryl-cAMP, a cell-permeable cAMP analogue, suppressed PNPLA7 mRNA at 4.5 g/L glucose. The abundance of PNPLA7 protein correlated inversely with the glucose concentrations. Collectively, our results highlight that PNPLA7 in human myotubes is regulated by metabolic signals, implicating a role for PNPLA7 in skeletal muscle energy metabolism.
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Affiliation(s)
- Katarina Miš
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Ana-Marija Lulić
- Biochemistry and Organic Analytical Chemistry Unit, Institute for Medical Research and Occupational Health, Zagreb, Croatia
| | - Tomaž Marš
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Sergej Pirkmajer
- Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
- *Correspondence: Sergej Pirkmajer, ; Maja Katalinić,
| | - Maja Katalinić
- Biochemistry and Organic Analytical Chemistry Unit, Institute for Medical Research and Occupational Health, Zagreb, Croatia
- *Correspondence: Sergej Pirkmajer, ; Maja Katalinić,
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7
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The Patatin-Like Phospholipase Domain Containing Protein 7 Regulates Macrophage Classical Activation through SIRT1/NF-κB and p38 MAPK Pathways. Int J Mol Sci 2022; 23:ijms232314983. [PMID: 36499308 PMCID: PMC9739533 DOI: 10.3390/ijms232314983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/25/2022] [Accepted: 11/28/2022] [Indexed: 12/03/2022] Open
Abstract
Lysophosphatidylcholine (LPC) is a bioactive lipid that modulates macrophage polarization during immune responses, inflammation, and tissue remodeling. Patatin-like phospholipase domain containing protein 7 (PNPLA7) is a lysophospholipase with a preference for LPC. However, the role of PNPLA7 in macrophage polarization as an LPC hydrolase has not been explored. In the current study, we found that PNPLA7 is highly expressed in naïve macrophages and downregulated upon lipopolysaccharide (LPS)-induced polarization towards the classically activated (M1) phenotype. Consistently, overexpression of PNPLA7 suppressed the expression of proinflammatory M1 marker genes, including interleukin 1β (IL-1β), IL-6, inducible nitric oxide synthase (iNOS), and tumor necrosis factor α (TNF-α), whereas knockdown of PNPLA7 augmented the inflammatory gene expression in LPS-challenged macrophages. PNPLA7 overexpression and knockdown increased and decreased Sirtuin1 (SIRT1) mRNA and protein levels, respectively, and affected the acetylation of the nuclear factor-kappa B (NF-κB) p65 subunit, a key transcription factor in M1 polarization. In addition, the levels of phosphorylated p38 mitogen-activated protein kinase (MAPK) were suppressed and enhanced by PNPLA7 overexpression and knockdown, respectively. Taken together, these findings suggest that PNPLA7 suppresses M1 polarization of LPS-challenged macrophages by modulating SIRT1/NF-κB- and p38 MAPK-dependent pathways.
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Lipid Dyshomeostasis and Inherited Cerebellar Ataxia. Mol Neurobiol 2022; 59:3800-3828. [PMID: 35420383 PMCID: PMC9148275 DOI: 10.1007/s12035-022-02826-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 04/01/2022] [Indexed: 12/04/2022]
Abstract
Cerebellar ataxia is a form of ataxia that originates from dysfunction of the cerebellum, but may involve additional neurological tissues. Its clinical symptoms are mainly characterized by the absence of voluntary muscle coordination and loss of control of movement with varying manifestations due to differences in severity, in the site of cerebellar damage and in the involvement of extracerebellar tissues. Cerebellar ataxia may be sporadic, acquired, and hereditary. Hereditary ataxia accounts for the majority of cases. Hereditary ataxia has been tentatively divided into several subtypes by scientists in the field, and nearly all of them remain incurable. This is mainly because the detailed mechanisms of these cerebellar disorders are incompletely understood. To precisely diagnose and treat these diseases, studies on their molecular mechanisms have been conducted extensively in the past. Accumulating evidence has demonstrated that some common pathogenic mechanisms exist within each subtype of inherited ataxia. However, no reports have indicated whether there is a common mechanism among the different subtypes of inherited cerebellar ataxia. In this review, we summarize the available references and databases on neurological disorders characterized by cerebellar ataxia and show that a subset of genes involved in lipid homeostasis form a new group that may cause ataxic disorders through a common mechanism. This common signaling pathway can provide a valuable reference for future diagnosis and treatment of ataxic disorders.
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Current Knowledge on Mammalian Phospholipase A1, Brief History, Structures, Biochemical and Pathophysiological Roles. Molecules 2022; 27:molecules27082487. [PMID: 35458682 PMCID: PMC9031518 DOI: 10.3390/molecules27082487] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 12/29/2022] Open
Abstract
Phospholipase A1 (PLA1) is an enzyme that cleaves an ester bond at the sn-1 position of glycerophospholipids, producing a free fatty acid and a lysophospholipid. PLA1 activities have been detected both extracellularly and intracellularly, which are well conserved in higher eukaryotes, including fish and mammals. All extracellular PLA1s belong to the lipase family. In addition to PLA1 activity, most mammalian extracellular PLA1s exhibit lipase activity to hydrolyze triacylglycerol, cleaving the fatty acid and contributing to its absorption into the intestinal tract and tissues. Some extracellular PLA1s exhibit PLA1 activities specific to phosphatidic acid (PA) or phosphatidylserine (PS) and serve to produce lysophospholipid mediators such as lysophosphatidic acid (LPA) and lysophosphatidylserine (LysoPS). A high level of PLA1 activity has been detected in the cytosol fractions, where PA-PLA1/DDHD1/iPLA1 was responsible for the activity. Many homologs of PA-PLA1 and PLA2 have been shown to exhibit PLA1 activity. Although much has been learned about the pathophysiological roles of PLA1 molecules through studies of knockout mice and human genetic diseases, many questions regarding their biochemical properties, including their genuine in vivo substrate, remain elusive.
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10
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Riegler-Berket L, Wechselberger L, Cerk IK, Padmanabha Das KM, Viertlmayr R, Kulminskaya N, Rodriguez Gamez CF, Schweiger M, Zechner R, Zimmermann R, Oberer M. Residues of the minimal sequence of G0S2 collectively contribute to ATGL inhibition while C-and N-terminal extensions promote binding to ATGL. Biochim Biophys Acta Mol Cell Biol Lipids 2022; 1867:159105. [PMID: 35026402 DOI: 10.1016/j.bbalip.2021.159105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 11/29/2021] [Accepted: 12/17/2021] [Indexed: 11/25/2022]
Abstract
The protein encoded by the G0/G1 switch gene 2 (G0S2) is a potent inhibitor of adipose triglyceride lipase (ATGL) and thus an important regulator of intracellular lipolysis. Since dysfunction of lipolysis is associated with metabolic diseases including diabetes and obesity, inhibition of ATGL is considered a therapeutic strategy. G0S2 interacts with ATGL's patatin-domain to mediate non-competitive inhibition, however atomic details of the inhibition mechanism are incompletely understood. Sequences of G0S2 from higher organisms show a highly conserved N-terminal part, including a hydrophobic region covering amino acids 27 to 42. We show that predicted G0S2 orthologs from platypus, chicken and Japanese rice-fish are able to inhibit human and mouse ATGL, emphasizing the contribution of conserved amino acid to ATGL inhibition. Our site directed mutagenesis and truncation studies give insights in the protein-protein interaction on a per-residue level. We determine that the minimal sequence required for ATGL inhibition ranges from amino acids 20 to 44. Residues Y27, V28, G30, A34 G37, V39 or L42 within this sequence play a substantial role in ATGL inhibition. Furthermore, we show that unspecific interactions of the N-terminal part (amino acids 20-27) of the minimal sequence facilitate the interaction to ATGL. Our studies also demonstrate that full-length G0S2 shows higher tolerance to specific single amino acid exchanges in the hydrophobic region due to the stronger contributions of unspecific interactions. However, exchanges of more than one amino-acid in the hydrophobic region also result in the loss of function as ATGL inhibitor even in the full-length protein.
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Affiliation(s)
- L Riegler-Berket
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - L Wechselberger
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - I K Cerk
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - K M Padmanabha Das
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA
| | - R Viertlmayr
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - N Kulminskaya
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | | | - M Schweiger
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria
| | - R Zechner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria; BioHealth Field of Excellence, University of Graz, 8010 Graz, Austria
| | - R Zimmermann
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria; BioHealth Field of Excellence, University of Graz, 8010 Graz, Austria
| | - M Oberer
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria; BioTechMed Graz, 8010 Graz, Austria; BioHealth Field of Excellence, University of Graz, 8010 Graz, Austria.
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11
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He J, Liu X, Liu L, Zeng S, Shan S, Liao Z. Identification of Novel Compound Heterozygous Variants of the PNPLA6 Gene in Boucher-Neuhäuser Syndrome. Front Genet 2022; 13:810537. [PMID: 35198007 PMCID: PMC8859865 DOI: 10.3389/fgene.2022.810537] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 01/05/2022] [Indexed: 12/11/2022] Open
Abstract
Background: Boucher–Neuhäuser syndrome (BNS, MIM 215470) is a rare autosomal recessive syndrome caused by mutations in the PNPLA6 gene. Few BNS cases have been reported for functional validation at the RNA level. Herein, we report on the family of a 17-year-old girl with clinical characteristics of BNS, genetic validation, and a systematic review of PNPLA6 variants related to BNS. Methods: Clinical data and blood samples were collected from the patient and their parents, and whole-exome sequencing was performed and confirmed by Sanger sequencing. RNA-sequencing (RNA-Seq) and quantitative RT-PCR (qRT-PCR) were performed, and the three-dimensional protein structures of the variants were predicted. Results: We report a 17-year-old female with progressive night blindness since the age of four, primary amenorrhea, and non-development of secondary sexual characteristics. Her impaired vision was diagnosed as retinal pigmentary degeneration of the retina. She had congenital hypogonadotropic hypogonadism (CHH) but no cerebellar ataxia at present. Two novel compound heterozygous variants (c.2241del/p.Met748TrpfsTer65 and c.2986A>G/p.Thr996Ala) of the PNPLA6 gene (NM_006702.4) were identified by whole-exome sequencing. The former variant was carried from her healthy father and has not been reported previously. The latter was inherited from her healthy mother and was noted in a report without functional studies. The RT-PCR results showed that the mRNA expression of PNPLA6 was lower in this patient and her father than in the control group. She was diagnosed with BNS. Both variants (c.2241del and c.2986A>G) were likely pathogenic according to the ACMG criteria. The novel variants in the PNPLA6 gene related to Boucher–Neuhäuser syndrome were summarized in this article. Conclusion: The possibility of Boucher–Neuhäuser syndrome should be considered when patients present with night blindness, impaired vision, and hypogonadotropic hypogonadism. Gene sequencing is currently the primary diagnostic method. Herein, novel compound heterozygous variants of PNPLA6 were identified in a BNS patient, and its function was verified at the RNA level. The PNPLA6 c.2241del variant is novel and potentially pathogenic, expanding the mutation spectrum in PNPLA6.
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Affiliation(s)
- Junyu He
- Department of Endocrinology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xin Liu
- Aegicare Technology Co., Ltd., Shenzhen, China
| | - Liyi Liu
- Department of Endocrinology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Shaohao Zeng
- Department of Endocrinology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Shuanghong Shan
- Department of Endocrinology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhihong Liao
- Department of Endocrinology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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Vogel P, Read RW, Hansen GM, Powell DR. Histopathology is required to identify and characterize myopathies in high-throughput phenotype screening of genetically engineered mice. Vet Pathol 2021; 58:1158-1171. [PMID: 34269122 DOI: 10.1177/03009858211030541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The development of mouse models that replicate the genetic and pathological features of human disease is important in preclinical research because these types of models enable the completion of meaningful pharmacokinetic, safety, and efficacy studies. Numerous relevant mouse models of human disease have been discovered in high-throughput screening programs, but there are important specific phenotypes revealed by histopathology that are not reliably detected by any other physiological or behavioral screening tests. As part of comprehensive phenotypic analyses of over 4000 knockout (KO) mice, histopathology identified 12 lines of KO mice with lesions indicative of an autosomal recessive myopathy. This report includes a brief summary of histological and other findings in these 12 lines. Notably, the inverted screen test detected muscle weakness in only 4 of these 12 lines (Scyl1, Plpp7, Chkb, and Asnsd1), all 4 of which have been previously recognized and published. In contrast, 6 of 8 KO lines showing negative or inconclusive findings on the inverted screen test (Plppr2, Pnpla7, Tenm1, Srpk3, Sidt2, Yif1b, Mrs2, and Pnpla2) had not been previously identified as having myopathies. These findings support the need to include histopathology in phenotype screening protocols in order to identify novel genetic myopathies that are not clinically evident or not detected by the inverted screen test.
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Affiliation(s)
- Peter Vogel
- 5417St Jude Children's Research Hospital, Memphis, TN, USA
| | - Robert W Read
- 57636Lexicon Pharmaceuticals Inc, The Woodlands, TX, USA
| | | | - David R Powell
- 57636Lexicon Pharmaceuticals Inc, The Woodlands, TX, USA
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13
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Wang X, Guo M, Wang Q, Wang Q, Zuo S, Zhang X, Tong H, Chen J, Wang H, Chen X, Guo J, Su X, Liang H, Zhou H, Li JZ. The Patatin-Like Phospholipase Domain Containing Protein 7 Facilitates VLDL Secretion by Modulating ApoE Stability. Hepatology 2020; 72:1569-1585. [PMID: 32103509 DOI: 10.1002/hep.31161] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Accepted: 01/21/2020] [Indexed: 12/16/2022]
Abstract
BACKGROUND AND AIMS The regulation of hepatic very-low-density lipoprotein (VLDL) secretion is vital for lipid metabolism whose pathogenetic status is involved in fatty liver disease and dyslipidemia seen in hepatic steatosis. Accumulated evidence suggest that apolipoprotein E (ApoE) is closely related to hepatic VLDL secretion. Here, we report that the expression of patatin-like phospholipase domain containing protein 7 (PNPLA7) is strongly induced by hepatic steatosis and positively correlates with plasma triacylglycerol (TAG) levels in the human subjects, whereas the role of PNPLA7 in hepatic VLDL secretion is unknown. APPROACH AND RESULTS Herein, with genetic manipulation in the mice, the deficiency of hepatic PNPLA7 expression resulted in reduced VLDL secretion accompanied by enhanced hepatic lipid accumulation and decreased hepatic ApoE expression. Furthermore, knockdown of PNPLA7 in the livers of the db/db mice also resulted in significant reduction in plasma TAG level but aggravated hepatic steatosis. Importantly, we observed that PNPLA7 interacted with ApoE and presumably at the site of endoplasmic reticulum. Mechanistically, we have shown that PNPLA7 could modulate polyubiquitination and proteasomal-mediated degradation of ApoE. Overexpressed ApoE restored the impaired VLDL-TAG metabolism in PNPLA7-knockdown primary hepatocytes. CONCLUSION PNPLA7 plays a critical role in regulating hepatic VLDL secretion by modulating ApoE stability through its interaction with ApoE.
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Affiliation(s)
- Xiuyun Wang
- The Key Laboratory of Rare Metabolic Disease, Nanjing Medical University, Nanjing, China.,Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, China.,The Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, Nanjing, China
| | - Min Guo
- The State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
| | - Qian Wang
- The Key Laboratory of Rare Metabolic Disease, Nanjing Medical University, Nanjing, China.,Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, China.,The Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, Nanjing, China
| | - Qingjie Wang
- The Key Laboratory of Rare Metabolic Disease, Nanjing Medical University, Nanjing, China.,Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, China.,The Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, Nanjing, China
| | - Shasha Zuo
- The Key Laboratory of Rare Metabolic Disease, Nanjing Medical University, Nanjing, China.,Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, China.,The Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, Nanjing, China
| | - Xu Zhang
- The Key Laboratory of Rare Metabolic Disease, Nanjing Medical University, Nanjing, China.,Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, China.,The Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, Nanjing, China
| | - Hui Tong
- The Key Laboratory of Rare Metabolic Disease, Nanjing Medical University, Nanjing, China.,Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, China.,The Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, Nanjing, China
| | - Jizheng Chen
- The State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, China
| | - Huimin Wang
- The Sate Key laboratory of Membrane Biology, Center for Life Science and Institute of Molecular Medicine, Peking University, Beijing, China
| | - Xiaowei Chen
- The Sate Key laboratory of Membrane Biology, Center for Life Science and Institute of Molecular Medicine, Peking University, Beijing, China
| | - Junyuan Guo
- Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, China
| | - Xiong Su
- Department of Biochemistry and Molecular Biology, Soochow University Medical College, Suzhou, China
| | - Hui Liang
- Department of General Surgery, The First affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Hongwen Zhou
- The Key Laboratory of Rare Metabolic Disease, Nanjing Medical University, Nanjing, China.,Department of Endocrinology, The First affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - John Zhong Li
- The Key Laboratory of Rare Metabolic Disease, Nanjing Medical University, Nanjing, China.,Department of Biochemistry and Molecular Biology, Nanjing Medical University, Nanjing, China.,The Key Laboratory of Human Functional Genomics of Jiangsu Province, Nanjing Medical University, Nanjing, China
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Murakami M, Sato H, Taketomi Y. Updating Phospholipase A 2 Biology. Biomolecules 2020; 10:E1457. [PMID: 33086624 PMCID: PMC7603386 DOI: 10.3390/biom10101457] [Citation(s) in RCA: 102] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 10/09/2020] [Accepted: 10/15/2020] [Indexed: 12/30/2022] Open
Abstract
The phospholipase A2 (PLA2) superfamily contains more than 50 enzymes in mammals that are subdivided into several distinct families on a structural and biochemical basis. In principle, PLA2 has the capacity to hydrolyze the sn-2 position of glycerophospholipids to release fatty acids and lysophospholipids, yet several enzymes in this superfamily catalyze other reactions rather than or in addition to the PLA2 reaction. PLA2 enzymes play crucial roles in not only the production of lipid mediators, but also membrane remodeling, bioenergetics, and body surface barrier, thereby participating in a number of biological events. Accordingly, disturbance of PLA2-regulated lipid metabolism is often associated with various diseases. This review updates the current state of understanding of the classification, enzymatic properties, and biological functions of various enzymes belonging to the PLA2 superfamily, focusing particularly on the novel roles of PLA2s in vivo.
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Affiliation(s)
- Makoto Murakami
- Laboratory of Microenvironmental and Metabolic Health Sciences, Center for Disease Biology and Integrative Medicine, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-8655, Japan; (H.S.); (Y.T.)
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15
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Chang P, Sun T, Heier C, Gao H, Xu H, Huang F. Interaction of the Lysophospholipase PNPLA7 with Lipid Droplets through the Catalytic Region. Mol Cells 2020; 43:286-297. [PMID: 32208367 PMCID: PMC7103881 DOI: 10.14348/molcells.2020.2283] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 01/28/2020] [Accepted: 02/10/2020] [Indexed: 12/25/2022] Open
Abstract
Mammalian patatin-like phospholipase domain containing proteins (PNPLAs) play critical roles in triglyceride hydrolysis, phospholipids metabolism, and lipid droplet (LD) homeostasis. PNPLA7 is a lysophosphatidylcholine hydrolase anchored on the endoplasmic reticulum which associates with LDs through its catalytic region (PNPLA7-C) in response to increased cyclic nucleotide levels. However, the interaction of PNPLA7 with LDs through its catalytic region is unknown. Herein, we demonstrate that PNPLA7-C localizes to the mature LDs ex vivo and also colocalizes with pre-existing LDs. Localization of PNPLA7-C with LDs induces LDs clustering via non-enzymatic intermolecular associations, while PNPLA7 alone does not induce LD clustering. Residues 742-1016 contains four putative transmembrane domains which act as a LD targeting motif and are required for the localization of PNPLA7-C to LDs. Furthermore, the N-terminal flanking region of the LD targeting motif, residues 681-741, contributes to the LD targeting, whereas the C-terminal flanking region (1169-1326) has an anti-LD targeting effect. Interestingly, the LD targeting motif does not exhibit lysophosphatidylcholine hydrolase activity even though it associates with LDs phospholipid membranes. These findings characterize the specific functional domains of PNPLA7 mediating subcellular positioning and interactions with LDs, as wells as providing critical insights into the structure of this evolutionarily conserved phospholipid-metabolizing enzyme family.
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Affiliation(s)
- Pingan Chang
- Chongqing Key Laboratory of Big Data for Bio-intelligence, School of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Tengteng Sun
- Chongqing Key Laboratory of Big Data for Bio-intelligence, School of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Christoph Heier
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Hao Gao
- Chongqing Key Laboratory of Big Data for Bio-intelligence, School of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Hongmei Xu
- Chongqing Key Laboratory of Big Data for Bio-intelligence, School of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Feifei Huang
- Chongqing Key Laboratory of Big Data for Bio-intelligence, School of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
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16
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Jolly A, Bayram Y, Turan S, Aycan Z, Tos T, Abali ZY, Hacihamdioglu B, Coban Akdemir ZH, Hijazi H, Bas S, Atay Z, Guran T, Abali S, Bas F, Darendeliler F, Colombo R, Barakat TS, Rinne T, White JJ, Yesil G, Gezdirici A, Gulec EY, Karaca E, Pehlivan D, Jhangiani SN, Muzny DM, Poyrazoglu S, Bereket A, Gibbs RA, Posey JE, Lupski JR. Exome Sequencing of a Primary Ovarian Insufficiency Cohort Reveals Common Molecular Etiologies for a Spectrum of Disease. J Clin Endocrinol Metab 2019; 104:3049-3067. [PMID: 31042289 PMCID: PMC6563799 DOI: 10.1210/jc.2019-00248] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 04/25/2019] [Indexed: 12/15/2022]
Abstract
CONTEXT Primary ovarian insufficiency (POI) encompasses a spectrum of premature menopause, including both primary and secondary amenorrhea. For 75% to 90% of individuals with hypergonadotropic hypogonadism presenting as POI, the molecular etiology is unknown. Common etiologies include chromosomal abnormalities, environmental factors, and congenital disorders affecting ovarian development and function, as well as syndromic and nonsyndromic single gene disorders suggesting POI represents a complex trait. OBJECTIVE To characterize the contribution of known disease genes to POI and identify molecular etiologies and biological underpinnings of POI. DESIGN, SETTING, AND PARTICIPANTS We applied exome sequencing (ES) and family-based genomics to 42 affected female individuals from 36 unrelated Turkish families, including 31 with reported parental consanguinity. RESULTS This analysis identified likely damaging, potentially contributing variants and molecular diagnoses in 16 families (44%), including 11 families with likely damaging variants in known genes and five families with predicted deleterious variants in disease genes (IGSF10, MND1, MRPS22, and SOHLH1) not previously associated with POI. Of the 16 families, 2 (13%) had evidence for potentially pathogenic variants at more than one locus. Absence of heterozygosity consistent with identity-by-descent mediated recessive disease burden contributes to molecular diagnosis in 15 of 16 (94%) families. GeneMatcher allowed identification of additional families from diverse genetic backgrounds. CONCLUSIONS ES analysis of a POI cohort further characterized locus heterogeneity, reaffirmed the association of genes integral to meiotic recombination, demonstrated the likely contribution of genes involved in hypothalamic development, and documented multilocus pathogenic variation suggesting the potential for oligogenic inheritance contributing to the development of POI.
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Affiliation(s)
- Angad Jolly
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Yavuz Bayram
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Serap Turan
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Zehra Aycan
- Department of Pediatric Endocrinology, Sami Ulus Children’s Hospital, Ankara, Turkey
| | - Tulay Tos
- Department of Medical Genetics, Sami Ulus Children’s Hospital, Ankara, Turkey
| | - Zehra Yavas Abali
- Department of Pediatric Endocrinology, İstanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | | | | | - Hadia Hijazi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Serpil Bas
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Zeynep Atay
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Tulay Guran
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Saygin Abali
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Firdevs Bas
- Department of Pediatric Endocrinology, İstanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Feyza Darendeliler
- Department of Pediatric Endocrinology, İstanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Roberto Colombo
- Center for the Study of Rare Inherited Diseases (CeSMER), Niguarda Ca' Granda Metropolitan Hospital, Milan, Italy
- Faculty of Medicine, Catholic University, IRCCS Policlinico Gemelli University Hospital, Rome, Italy
| | - Tahsin Stefan Barakat
- Department of Clinical Genetics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Tuula Rinne
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Janson J White
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
| | - Gozde Yesil
- Department of Medical Genetics, Bezmialem University, Istanbul, Turkey
| | - Alper Gezdirici
- Department of Medical Genetics, Kanuni Sultan Suleyman Training and Research Hospital, Istanbul, Turkey
| | - Elif Yilmaz Gulec
- Department of Medical Genetics, Kanuni Sultan Suleyman Training and Research Hospital, Istanbul, Turkey
| | - Ender Karaca
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama
| | - Davut Pehlivan
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
- Section of Pediatric Neurology and Developmental Neuroscience, Department of Pediatrics, Baylor College of Medicine, Houston, Texas
| | | | - Donna M Muzny
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas
| | - Sukran Poyrazoglu
- Department of Pediatric Endocrinology, İstanbul Faculty of Medicine, Istanbul University, Istanbul, Turkey
| | - Abdullah Bereket
- Department of Pediatric Endocrinology and Diabetes, Marmara University School of Medicine, Istanbul, Turkey
| | - Richard A Gibbs
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas
| | - Jennifer E Posey
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
- Correspondence and Reprint Requests: James R. Lupski, MD, PhD, DSc (Hon), FAAP, FACMG, FANA, FAAAS, FAAS, Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room 604B, Houston, Texas 77030. E-mail: ; or Jennifer E. Posey, MD, PhD, FACMG, Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room T603, Houston, Texas 77030. E-mail:
| | - James R Lupski
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, Texas
- Department of Pediatrics, Baylor College of Medicine, Houston, Texas
- Texas Children’s Hospital, Houston, Texas
- Correspondence and Reprint Requests: James R. Lupski, MD, PhD, DSc (Hon), FAAP, FACMG, FANA, FAAAS, FAAS, Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room 604B, Houston, Texas 77030. E-mail: ; or Jennifer E. Posey, MD, PhD, FACMG, Department of Molecular and Human Genetics, Baylor College of Medicine, One Baylor Plaza, Room T603, Houston, Texas 77030. E-mail:
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Mapping QTL for white striping in relation to breast muscle yield and meat quality traits in broiler chickens. BMC Genomics 2018; 19:202. [PMID: 29554873 PMCID: PMC5859760 DOI: 10.1186/s12864-018-4598-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Accepted: 03/13/2018] [Indexed: 11/23/2022] Open
Abstract
Background White striping (WS) is an emerging muscular defect occurring on breast and thigh muscles of broiler chickens. It is characterized by the presence of white striations parallel to the muscle fibers and has significant consequences for meat quality. The etiology of WS remains poorly understood, even if previous studies demonstrated that the defect prevalence is related to broiler growth and muscle development. Moreover, recent studies showed moderate to high heritability values of WS, which emphasized the role of genetics in the expression of the muscle defect. The aim of this study was to identify the first quantitative trait loci (QTLs) for WS as well as breast muscle yield (BMY) and meat quality traits using a genome-wide association study (GWAS). We took advantage of two divergent lines of chickens selected for meat quality through Pectoralis major ultimate pH (pHu) and which exhibit the muscular defect. An expression QTL (eQTL) detection was further performed for some candidate genes, either suggested by GWAS analysis or based on their biological function. Results Forty-two single nucleotide polymorphisms (SNPs) associated with WS and other meat quality traits were identified. They defined 18 QTL regions located on 13 chromosomes. These results supported a polygenic inheritance of the studied traits and highlighted a few pleiotropic regions. A set of 16 positional and/or functional candidate genes was designed for further eQTL detection. A total of 132 SNPs were associated with molecular phenotypes and defined 21 eQTL regions located on 16 chromosomes. Interestingly, several co-localizations between QTL and eQTL regions were observed which could suggest causative genes and gene networks involved in the variability of meat quality traits and BMY. Conclusions The QTL mapping carried out in the current study for WS did not support the existence of a major gene, but rather suggested a polygenic inheritance of the defect and of other studied meat quality traits. We identified several candidate genes involved in muscle metabolism and structure and in muscular dystrophies. The eQTL analyses showed that they were part of molecular networks associated with WS and meat quality phenotypes and suggested a few putative causative genes. Electronic supplementary material The online version of this article (10.1186/s12864-018-4598-9) contains supplementary material, which is available to authorized users.
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18
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Effects of maternal obesity on Wharton's Jelly mesenchymal stromal cells. Sci Rep 2017; 7:17595. [PMID: 29242640 PMCID: PMC5730612 DOI: 10.1038/s41598-017-18034-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Accepted: 12/05/2017] [Indexed: 01/03/2023] Open
Abstract
We investigated whether maternal metabolic environment affects mesenchymal stromal/stem cells (MSCs) from umbilical cord’s Wharton’s Jelly (WJ) on a molecular level, and potentially render them unsuitable for clinical use in multiple recipients. In this pilot study on umbilical cords post partum from healthy non-obese (BMI = 19–25; n = 7) and obese (BMI ≥ 30; n = 7) donors undergoing elective Cesarean section, we found that WJ MSC from obese donors showed slower population doubling and a stronger immunosuppressive activity. Genome-wide DNA methylation of triple positive (CD73+CD90+CD105+) WJ MSCs found 67 genes with at least one CpG site where the methylation difference was ≥0.2 in four or more obese donors. Only one gene, PNPLA7, demonstrated significant difference on methylome, transcriptome and protein level. Although the number of analysed donors is limited, our data suggest that the altered metabolic environment related to excessive body weight might bear consequences on the WJ MSCs.
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Collet TH, Sonoyama T, Henning E, Keogh JM, Ingram B, Kelway S, Guo L, Farooqi IS. A Metabolomic Signature of Acute Caloric Restriction. J Clin Endocrinol Metab 2017; 102:4486-4495. [PMID: 29029202 PMCID: PMC5718701 DOI: 10.1210/jc.2017-01020] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 09/19/2017] [Indexed: 11/30/2022]
Abstract
CONTEXT The experimental paradigm of acute caloric restriction (CR) followed by refeeding (RF) can be used to study the homeostatic mechanisms that regulate energy homeostasis, which are relevant to understanding the adaptive response to weight loss. OBJECTIVE Metabolomics, the measurement of hundreds of small molecule metabolites, their precursors, derivatives, and degradation products, has emerged as a useful tool for the study of physiology and disease and was used here to study the metabolic response to acute CR. PARTICIPANTS, DESIGN, AND SETTING We used four ultra high-performance liquid chromatography-tandem mass spectrometry methods to characterize changes in carbohydrates, lipids, amino acids, and steroids in eight normal weight men at baseline, after 48 hours of CR (10% of energy requirements) and after 48 hours of ad libitum RF in a tightly controlled environment. RESULTS We identified a distinct metabolomic signature associated with acute CR characterized by the expected switch from carbohydrate to fat utilization with increased lipolysis and β-fatty acid oxidation. We found an increase in ω-fatty acid oxidation and levels of endocannabinoids, which are known to promote food intake. These changes were reversed with RF. Several plasmalogen phosphatidylethanolamines (endogenous antioxidants) significantly decreased with CR (all P ≤ 0.0007). Additionally, acute CR was associated with an increase in the branched chain amino acids (all P ≤ 1.4 × 10-7) and dehydroepiandrosterone sulfate (P = 0.0006). CONCLUSIONS We identified a distinct metabolomic signature associated with acute CR. Further studies are needed to characterize the mechanisms that mediate these changes and their potential contribution to the adaptive response to dietary restriction.
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Affiliation(s)
- Tinh-Hai Collet
- University of Cambridge Metabolic Research Laboratories and National Institute for Health Research Cambridge Biomedical Research Centre, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, CB2 0QQ, United Kingdom
- Service of Endocrinology, Diabetes and Metabolism, Lausanne University Hospital, 1011 Lausanne, Switzerland
| | - Takuhiro Sonoyama
- University of Cambridge Metabolic Research Laboratories and National Institute for Health Research Cambridge Biomedical Research Centre, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, CB2 0QQ, United Kingdom
| | - Elana Henning
- University of Cambridge Metabolic Research Laboratories and National Institute for Health Research Cambridge Biomedical Research Centre, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, CB2 0QQ, United Kingdom
| | - Julia M. Keogh
- University of Cambridge Metabolic Research Laboratories and National Institute for Health Research Cambridge Biomedical Research Centre, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, CB2 0QQ, United Kingdom
| | | | - Sarah Kelway
- University of Cambridge Metabolic Research Laboratories and National Institute for Health Research Cambridge Biomedical Research Centre, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, CB2 0QQ, United Kingdom
| | - Lining Guo
- Metabolon, Inc., Durham, North Carolina 27713
| | - I. Sadaf Farooqi
- University of Cambridge Metabolic Research Laboratories and National Institute for Health Research Cambridge Biomedical Research Centre, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Addenbrooke’s Hospital, Cambridge, CB2 0QQ, United Kingdom
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20
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Heier C, Kien B, Huang F, Eichmann TO, Xie H, Zechner R, Chang PA. The phospholipase PNPLA7 functions as a lysophosphatidylcholine hydrolase and interacts with lipid droplets through its catalytic domain. J Biol Chem 2017; 292:19087-19098. [PMID: 28887301 PMCID: PMC5704489 DOI: 10.1074/jbc.m117.792978] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 08/31/2017] [Indexed: 01/04/2023] Open
Abstract
Mammalian patatin-like phospholipase domain–containing proteins (PNPLAs) are lipid-metabolizing enzymes with essential roles in energy metabolism, skin barrier development, and brain function. A detailed annotation of enzymatic activities and structure–function relationships remains an important prerequisite to understand PNPLA functions in (patho-)physiology, for example, in disorders such as neutral lipid storage disease, non-alcoholic fatty liver disease, and neurodegenerative syndromes. In this study, we characterized the structural features controlling the subcellular localization and enzymatic activity of PNPLA7, a poorly annotated phospholipase linked to insulin signaling and energy metabolism. We show that PNPLA7 is an endoplasmic reticulum (ER) transmembrane protein that specifically promotes hydrolysis of lysophosphatidylcholine in mammalian cells. We found that transmembrane and regulatory domains in the PNPLA7 N-terminal region cooperate to regulate ER targeting but are dispensable for substrate hydrolysis. Enzymatic activity is instead mediated by the C-terminal domain, which maintains full catalytic competence even in the absence of N-terminal regions. Upon elevated fatty acid flux, the catalytic domain targets cellular lipid droplets and promotes interactions of PNPLA7 with these organelles in response to increased cAMP levels. We conclude that PNPLA7 acts as an ER-anchored lysophosphatidylcholine hydrolase that is composed of specific functional domains mediating catalytic activity, subcellular positioning, and interactions with cellular organelles. Our study provides critical structural insights into an evolutionarily conserved class of phospholipid-metabolizing enzymes.
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Affiliation(s)
- Christoph Heier
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Benedikt Kien
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Feifei Huang
- Key Laboratory of Molecular Biology, School of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
| | - Thomas O Eichmann
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Hao Xie
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Rudolf Zechner
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria.,BioTechMed-Graz, 8010 Graz, Austria, and
| | - Ping-An Chang
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria, .,Key Laboratory of Molecular Biology, School of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing 400065, China
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21
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Huang FF, Chang PA, Sun LX, Qin WZ, Han LP, Chen R. The destruction box is involved in the degradation of the NTE family proteins by the proteasome. Mol Biol Rep 2016; 43:1285-1292. [PMID: 27558092 DOI: 10.1007/s11033-016-4063-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 08/16/2016] [Indexed: 01/16/2023]
Abstract
Neuropathy target esterase (NTE) and NTE-related esterase (NRE) are endoplasmic reticulum (ER) membrane-anchored proteins belonging to the NTE protein family. NTE and NRE are degraded by macroautophagy and by the ubiquitin-proteasome pathway. However, the regulation of NTE and NRE by proteasome has not been well understood. Western blotting showed that the deletion of the regulatory region of NTE and NRE led to protein accumulation compared with that of the corresponding wild-type proteins. Further, deletion and site-directed mutagenesis experiments demonstrated that the destruction (D) box was required for the proteasomal degradation of NTE and NRE. However, unlike the deletion of the regulatory region, the deletion of the D box did not affect the subcellular localisation of NTE or NRE or disrupt the ER. Moreover, the deletion of the D box or the regulatory region of NTE has similar inhibitory effects on cell growth, which are greater than those produced by the full-length NTE. Here, for the first time, we show that the D box is involved in the regulation of NTE family proteins by the proteasome but not in their subcellular localisation. In addition, these results suggest that the NTE overexpression-mediated inhibition of cell growth is related to active protein levels but not to its ER disruption effect.
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Affiliation(s)
- Fei-Fei Huang
- Key Laboratory of Molecular Biology, College of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing, 400065, People's Republic of China
| | - Ping-An Chang
- Key Laboratory of Molecular Biology, College of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing, 400065, People's Republic of China.
| | - Lan-Xi Sun
- Key Laboratory of Molecular Biology, College of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing, 400065, People's Republic of China
| | - Wen-Zhen Qin
- Key Laboratory of Molecular Biology, College of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing, 400065, People's Republic of China
| | - Li-Ping Han
- Key Laboratory of Molecular Biology, College of Bio-information, Chongqing University of Posts and Telecommunications, Chongqing, 400065, People's Republic of China
| | - Rui Chen
- CAS Key Lab for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology of China, Beijing, 100190, People's Republic of China
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22
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Zhang S, Wang Y, Cui L, Deng Y, Xu S, Yu J, Cichello S, Serrero G, Ying Y, Liu P. Morphologically and Functionally Distinct Lipid Droplet Subpopulations. Sci Rep 2016; 6:29539. [PMID: 27386790 PMCID: PMC4937419 DOI: 10.1038/srep29539] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 06/20/2016] [Indexed: 12/12/2022] Open
Abstract
Lipid droplet (LD), a multi-functional organelle, is often found to associate with other cellular membranous structures and vary in size in a given cell, which may be related to their functional diversity. Here we established a method to separate LD subpopulations from isolated CHO K2 LDs into three different size categories. The subpopulation with smallest LDs was nearly free of ER and other membranous structures while those with larger LDs contained intact ER. These distinct subpopulations of LDs differed in their protein composition and ability to recruit proteins. This method was also applicable to LDs obtained from other sources, such as Huh7 cells, mouse liver and brown adipose tissue, et al. We developed an in vitro assay requiring only isolated LDs, Coenzyme A, and ATP to drive lipid synthesis. The LD subpopulation nearly depleted of ER was able to incorporate fatty acids into triacylglycerol and phospholipids. Together, our data demonstrate that LDs in a given cell are heterogeneous in size and function, and suggest that LDs are one of cellular lipid synthetic organelles.
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Affiliation(s)
- Shuyan Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Yang Wang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Liujuan Cui
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yaqin Deng
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Shimeng Xu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinhai Yu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Simon Cichello
- School of Life Sciences, La Trobe University, Melbourne Victoria 3086, Australia
| | | | - Yunshu Ying
- University of Texas Southwestern Medical Center, Dallas 75390, USA
| | - Pingsheng Liu
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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23
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Zhang X, Zhang J, Wang R, Guo S, Zhang H, Ma Y, Liu Q, Chu H, Xu X, Zhang Y, Yang D, Wang J, Liu J. Hypermethylation reduces the expression of PNPLA7 in hepatocellular carcinoma. Oncol Lett 2016; 12:670-674. [PMID: 27347198 DOI: 10.3892/ol.2016.4660] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 05/05/2016] [Indexed: 12/17/2022] Open
Abstract
Liver cancer has a high morbidity and mortality rate, and is one of the most common types of cancer in men. PNPLA7 is a member of the patatin-like phospholipase domain-containing protein family which is involved in triglyceride hydrolysis, energy metabolism and lipid droplet metabolism. The liver is the most important energy metabolism organ; whether PNPLA7 is deregulated in liver cancer has not been previously reported. In the present study, reverse transcription-quantitative polymerase chain reaction and subsequent methylation analysis provided evidence that PNPLA7 is down-regulated in hepatocellular carcinoma (HCC) cell lines and tissue samples, via the mechanism of transcriptional silencing by promoter hypermethylation. These results may provide novel insights for HCC diagnosis.
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Affiliation(s)
- Xiaojiao Zhang
- Department of Digestive Diseases, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China; Department of Immunology of Shanghai Medical School, Institutes of Biomedical Sciences, Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai 200032, P.R. China; Department of Chemistry, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, P.R. China
| | - Jun Zhang
- Department of Digestive Diseases, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China
| | - Rui Wang
- Department of Digestive Diseases, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China; Department of Immunology of Shanghai Medical School, Institutes of Biomedical Sciences, Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai 200032, P.R. China
| | - Shicheng Guo
- Ministry of Education (MOE) Key Laboratory of Contemporary Anthropology, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, P.R. China
| | - Huilu Zhang
- Department of Digestive Diseases, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China
| | - Yanyun Ma
- Ministry of Education (MOE) Key Laboratory of Contemporary Anthropology, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, P.R. China
| | - Qingmei Liu
- Ministry of Education (MOE) Key Laboratory of Contemporary Anthropology, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, P.R. China
| | - Haiyan Chu
- Ministry of Education (MOE) Key Laboratory of Contemporary Anthropology, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, P.R. China
| | - Xianghong Xu
- Ministry of Education (MOE) Key Laboratory of Contemporary Anthropology, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, P.R. China
| | - Yitong Zhang
- Department of Digestive Diseases, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China
| | - Dongqin Yang
- Department of Digestive Diseases, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China
| | - Jiucun Wang
- Ministry of Education (MOE) Key Laboratory of Contemporary Anthropology, State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai 200433, P.R. China
| | - Jie Liu
- Department of Digestive Diseases, Huashan Hospital, Fudan University, Shanghai 200040, P.R. China; Department of Immunology of Shanghai Medical School, Institutes of Biomedical Sciences, Collaborative Innovation Center of Genetics and Development, Fudan University, Shanghai 200032, P.R. China
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24
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Heck MV, Azizov M, Stehning T, Walter M, Kedersha N, Auburger G. Dysregulated expression of lipid storage and membrane dynamics factors in Tia1 knockout mouse nervous tissue. Neurogenetics 2015; 15:135-44. [PMID: 24659297 PMCID: PMC3994287 DOI: 10.1007/s10048-014-0397-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 03/03/2014] [Indexed: 12/13/2022]
Abstract
During cell stress, the transcription and translation of immediate early genes are prioritized, while most other messenger RNAs (mRNAs) are stored away in stress granules or degraded in processing bodies (P-bodies). TIA-1 is an mRNA-binding protein that needs to translocate from the nucleus to seed the formation of stress granules in the cytoplasm. Because other stress granule components such as TDP-43, FUS, ATXN2, SMN, MAPT, HNRNPA2B1, and HNRNPA1 are crucial for the motor neuron diseases amyotrophic lateral sclerosis (ALS)/spinal muscular atrophy (SMA) and for the frontotemporal dementia (FTD), here we studied mouse nervous tissue to identify mRNAs with selective dependence on Tia1 deletion. Transcriptome profiling with oligonucleotide microarrays in comparison of spinal cord and cerebellum, together with independent validation in quantitative reverse transcriptase PCR and immunoblots demonstrated several strong and consistent dysregulations. In agreement with previously reported TIA1 knock down effects, cell cycle and apoptosis regulators were affected markedly with expression changes up to +2-fold, exhibiting increased levels for Cdkn1a, Ccnf, and Tprkb vs. decreased levels for Bid and Inca1 transcripts. Novel and surprisingly strong expression alterations were detected for fat storage and membrane trafficking factors, with prominent +3-fold upregulations of Plin4, Wdfy1, Tbc1d24, and Pnpla2 vs. a −2.4-fold downregulation of Cntn4 transcript, encoding an axonal membrane adhesion factor with established haploinsufficiency. In comparison, subtle effects on the RNA processing machinery included up to 1.2-fold upregulations of Dcp1b and Tial1. The effect on lipid dynamics factors is noteworthy, since also the gene deletion of Tardbp (encoding TDP-43) and Atxn2 led to fat metabolism phenotypes in mouse. In conclusion, genetic ablation of the stress granule nucleator TIA-1 has a novel major effect on mRNAs encoding lipid homeostasis factors in the brain, similar to the fasting effect.
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Affiliation(s)
- Melanie Vanessa Heck
- Experimental Neurology, Department of Neurology, Goethe University Medical School, Building 89, 3rd floor, Theodor Stern Kai 7, 60590 Frankfurt am Main, Germany
| | - Mekhman Azizov
- Experimental Neurology, Department of Neurology, Goethe University Medical School, Building 89, 3rd floor, Theodor Stern Kai 7, 60590 Frankfurt am Main, Germany
| | - Tanja Stehning
- Experimental Neurology, Department of Neurology, Goethe University Medical School, Building 89, 3rd floor, Theodor Stern Kai 7, 60590 Frankfurt am Main, Germany
| | - Michael Walter
- Institute for Medical Genetics, Eberhard-Karls-University of Tuebingen, 72076 Tübingen, Germany
| | - Nancy Kedersha
- Division of Rheumatology, Immunology and Allergy, Brigham and Women’s Hospital, Smith 652, One Jimmy Fund Way, Boston, MA 02115 USA
| | - Georg Auburger
- Experimental Neurology, Department of Neurology, Goethe University Medical School, Building 89, 3rd floor, Theodor Stern Kai 7, 60590 Frankfurt am Main, Germany
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25
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Cerk IK, Salzburger B, Boeszoermenyi A, Heier C, Pillip C, Romauch M, Schweiger M, Cornaciu I, Lass A, Zimmermann R, Zechner R, Oberer M. A peptide derived from G0/G1 switch gene 2 acts as noncompetitive inhibitor of adipose triglyceride lipase. J Biol Chem 2014; 289:32559-70. [PMID: 25258314 PMCID: PMC4239610 DOI: 10.1074/jbc.m114.602599] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The protein G0/G1 switch gene 2 (G0S2) is a small basic protein that functions as an endogenous inhibitor of adipose triglyceride lipase (ATGL), a key enzyme in intracellular lipolysis. In this study, we identified a short sequence covering residues Lys-20 to Ala-52 in G0S2 that is still fully capable of inhibiting mouse and human ATGL. We found that a synthetic peptide corresponding to this region inhibits ATGL in a noncompetitive manner in the nanomolar range. This peptide is highly selective for ATGL and does not inhibit other lipases, including hormone-sensitive lipase, monoacylglycerol lipase, lipoprotein lipase, and patatin domain-containing phospholipases 6 and 7. Because increased lipolysis is linked to the development of metabolic disorders, the inhibition of ATGL by G0S2-derived peptides may represent a novel therapeutic tool to modulate lipolysis.
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Affiliation(s)
- Ines K Cerk
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Barbara Salzburger
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Andras Boeszoermenyi
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Christoph Heier
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Christoph Pillip
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Matthias Romauch
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Martina Schweiger
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Irina Cornaciu
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Achim Lass
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Robert Zimmermann
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Rudolf Zechner
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Monika Oberer
- From the Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
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26
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Silencing of drpr leads to muscle and brain degeneration in adult Drosophila. THE AMERICAN JOURNAL OF PATHOLOGY 2014; 184:2653-61. [PMID: 25111228 DOI: 10.1016/j.ajpath.2014.06.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Revised: 06/12/2014] [Accepted: 06/16/2014] [Indexed: 01/26/2023]
Abstract
Mutations in the gene encoding the single transmembrane receptor multiple epidermal growth factor-like domain 10 (MEGF10) cause an autosomal recessive congenital muscle disease in humans. Although mammalian MEGF10 is expressed in the central nervous system as well as in skeletal muscle, patients carrying mutations in MEGF10 do not show symptoms of central nervous system dysfunction. drpr is the sole Drosophila homolog of the human genes MEGF10, MEGF11, and MEGF12 (JEDI, PEAR). The functional domains of MEGF10 and drpr bear striking similarities, and residues affected by MEGF10 mutations in humans are conserved in drpr. Our analysis of drpr mutant flies revealed muscle degeneration with fiber size variability and vacuolization, as well as reduced motor performance, features that have been observed in human MEGF10 myopathy. Vacuolization was also seen in the brain. Tissue-specific RNAi experiments demonstrated that drpr deficiency in muscle, but not in the brain, leads to locomotor defects. The histological and behavioral abnormalities seen in the affected flies set the stage for further studies examining the signaling pathway modulated by MEGF10/Drpr in muscle, as well as assessing the effects of genetic and/or pharmacological manipulations on the observed muscle defects. In addition, the absence of functional redundancy for Drpr in Drosophila may help elucidate whether paralogs of MEGF10 in humans (eg, MEGF11) contribute to maintaining wild-type function in the human brain.
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27
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pPLA: Patatin-Related Phospholipase As with Multiple Biological Functions. SIGNALING AND COMMUNICATION IN PLANTS 2014. [DOI: 10.1007/978-3-642-42011-5_5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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28
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Fontes-Oliveira CC, Busquets S, Fuster G, Ametller E, Figueras M, Olivan M, Toledo M, López-Soriano FJ, Qu X, Demuth J, Stevens P, Varbanov A, Wang F, Isfort RJ, Argilés JM. A differential pattern of gene expression in skeletal muscle of tumor-bearing rats reveals dysregulation of excitation-contraction coupling together with additional muscle alterations. Muscle Nerve 2013; 49:233-48. [DOI: 10.1002/mus.23893] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2012] [Revised: 04/19/2013] [Accepted: 04/24/2013] [Indexed: 12/31/2022]
Affiliation(s)
- Cibely Cristine Fontes-Oliveira
- Cancer Research Group, Departament de Bioquímica i Biologia Molecular, Facultat de Biologia; Universitat de Barcelona; Diagonal 643 Barcelona 08028 Spain
| | - Sílvia Busquets
- Cancer Research Group, Departament de Bioquímica i Biologia Molecular, Facultat de Biologia; Universitat de Barcelona; Diagonal 643 Barcelona 08028 Spain
- Institut de Biomedicina de la Universitat de Barcelona; Barcelona Spain
| | - Gemma Fuster
- Cancer Research Group, Departament de Bioquímica i Biologia Molecular, Facultat de Biologia; Universitat de Barcelona; Diagonal 643 Barcelona 08028 Spain
| | - Elisabet Ametller
- Cancer Research Group, Departament de Bioquímica i Biologia Molecular, Facultat de Biologia; Universitat de Barcelona; Diagonal 643 Barcelona 08028 Spain
| | - Maite Figueras
- Cancer Research Group, Departament de Bioquímica i Biologia Molecular, Facultat de Biologia; Universitat de Barcelona; Diagonal 643 Barcelona 08028 Spain
| | - Mireia Olivan
- Cancer Research Group, Departament de Bioquímica i Biologia Molecular, Facultat de Biologia; Universitat de Barcelona; Diagonal 643 Barcelona 08028 Spain
| | - Míriam Toledo
- Cancer Research Group, Departament de Bioquímica i Biologia Molecular, Facultat de Biologia; Universitat de Barcelona; Diagonal 643 Barcelona 08028 Spain
| | - Francisco J. López-Soriano
- Cancer Research Group, Departament de Bioquímica i Biologia Molecular, Facultat de Biologia; Universitat de Barcelona; Diagonal 643 Barcelona 08028 Spain
- Institut de Biomedicina de la Universitat de Barcelona; Barcelona Spain
| | - Xiaoyan Qu
- Procter & Gamble; Mason Business Center; 8700 Mason-Montgomery Road Mason Ohio 45040 USA
| | - Jeffrey Demuth
- Procter & Gamble; Mason Business Center; 8700 Mason-Montgomery Road Mason Ohio 45040 USA
| | - Paula Stevens
- Procter & Gamble; Mason Business Center; 8700 Mason-Montgomery Road Mason Ohio 45040 USA
| | - Alex Varbanov
- Procter & Gamble; Mason Business Center; 8700 Mason-Montgomery Road Mason Ohio 45040 USA
| | - Feng Wang
- Procter & Gamble; Mason Business Center; 8700 Mason-Montgomery Road Mason Ohio 45040 USA
| | - Robert J. Isfort
- Procter & Gamble; Mason Business Center; 8700 Mason-Montgomery Road Mason Ohio 45040 USA
| | - Josep M. Argilés
- Cancer Research Group, Departament de Bioquímica i Biologia Molecular, Facultat de Biologia; Universitat de Barcelona; Diagonal 643 Barcelona 08028 Spain
- Institut de Biomedicina de la Universitat de Barcelona; Barcelona Spain
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29
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Development of small-molecule inhibitors targeting adipose triglyceride lipase. Nat Chem Biol 2013; 9:785-7. [PMID: 24096302 PMCID: PMC3829776 DOI: 10.1038/nchembio.1359] [Citation(s) in RCA: 153] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 08/29/2013] [Indexed: 01/03/2023]
Abstract
Adipose triglyceride lipase (ATGL) is rate limiting in the mobilization of fatty acids from cellular triglyceride stores. This central role in lipolysis marks ATGL as an interesting pharmacological target as deregulated fatty acid metabolism is closely linked to dyslipidemic and metabolic disorders. Here we report on the development and characterization of a small-molecule inhibitor of ATGL. Atglistatin is selective for ATGL and reduces fatty acid mobilization in vitro and in vivo.
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30
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Identification of human patatin-like phospholipase domain-containing protein 1 and a mutant in human cervical cancer HeLa cells. Mol Biol Rep 2013; 40:5597-605. [PMID: 24057234 DOI: 10.1007/s11033-013-2661-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2013] [Accepted: 09/14/2013] [Indexed: 01/04/2023]
Abstract
Recently members of mammalian patatin-like phospholipase domain containing (PNPLA) protein family have attracted attention for their critical roles in diverse aspects of lipid metabolism and signal pathway. Until now little has been known about the characteristics of PNPLA1. Here, the full length coding cDNA sequence of human PNPLA1 (hPNPLA1) was cloned for the first time, which encoded a polypeptide with 532 amino acids containing the whole patatin domain. Tissue expression profiles analysis showed that low mRNA levels of hPNPLA1 existed in various tissues, except high expression in the digestive system, bone marrow and spleen. Subcellular distribution of hPNPLA1 tagged with green fluorescence protein mainly localized to lipid droplets. Furthermore, a nonsense mutation of PNPLA1 in human cervical cancer HeLa cells was identified. The hPNPLA1 mutant encoded a protein of 412 amino acids without the C-terminal domain and did not colocalize to lipid droplets, which suggested that the C-terminal region of hPNPLA1 affected lipid droplet binding. These results identified hPNPLA1 and a mutant in HeLa cells, and provided insights into the structure and function of PNPLA1.
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31
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Thiel K, Heier C, Haberl V, Thul PJ, Oberer M, Lass A, Jäckle H, Beller M. The evolutionarily conserved protein CG9186 is associated with lipid droplets, required for their positioning and for fat storage. J Cell Sci 2013; 126:2198-212. [PMID: 23525007 DOI: 10.1242/jcs.120493] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Lipid droplets (LDs) are specialized cell organelles for the storage of energy-rich lipids. Although lipid storage is a conserved feature of all cells and organisms, little is known about fundamental aspects of the cell biology of LDs, including their biogenesis, structural assembly and subcellular positioning, and the regulation of organismic energy homeostasis. We identified a novel LD-associated protein family, represented by the Drosophila protein CG9186 and its murine homolog MGI:1916082. In the absence of LDs, both proteins localize at the endoplasmic reticulum (ER). Upon lipid storage induction, they translocate to LDs using an evolutionarily conserved targeting mechanism that acts through a 60-amino-acid targeting motif in the center of the CG9186 protein. Overexpression of CG9186, and MGI:1916082, causes clustering of LDs in both tissue culture and salivary gland cells, whereas RNAi knockdown of CG9186 results in a reduction of LDs. Organismal RNAi knockdown of CG9186 results in a reduction in lipid storage levels of the fly. The results indicate that we identified the first members of a novel and evolutionarily conserved family of lipid storage regulators, which are also required to properly position LDs within cells.
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Affiliation(s)
- Katharina Thiel
- Department of Molecular Developmental Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
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32
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Retraction. Protein domains, catalytic activity, and subcellular distribution of mouse NTE-related esterase. Mol Cell Biochem 2013; 371:233. [PMID: 23281490 DOI: 10.1007/s11010-009-0185-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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33
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Richardson RJ, Hein ND, Wijeyesakere SJ, Fink JK, Makhaeva GF. Neuropathy target esterase (NTE): overview and future. Chem Biol Interact 2012; 203:238-44. [PMID: 23220002 DOI: 10.1016/j.cbi.2012.10.024] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2012] [Revised: 10/22/2012] [Accepted: 10/30/2012] [Indexed: 11/29/2022]
Abstract
Neuropathy target esterase (NTE) was discovered by M.K. Johnson in his quest for the entity responsible for the striking and mysterious paralysis brought about by certain organophosphorus (OP) esters. His pioneering work on OP neuropathy led to the view that the biochemical lesion consisted of NTE that had undergone OP inhibition and aging. Indeed, nonaging NTE inhibitors failed to produce disease but protected against neuropathy from subsequently administered aging inhibitors. Thus, inhibition of NTE activity was not the culprit; rather, formation of an abnormal protein was the agent of the disorder. More recently, however, Paul Glynn and colleagues showed that whereas conventional knockout of the NTE gene was embryonic lethal, conditional knockout of central nervous system NTE produced neurodegeneration, suggesting to these authors that the absence of NTE rather than its presence in some altered form caused disease. We now know that NTE is the 6th member of a 9-protein family called patatin-like phospholipase domain-containing proteins, PNPLA1-9. Mutations in the catalytic domain of NTE (PNPLA6) are associated with a slowly developing disease akin to OP neuropathy and hereditary spastic paraplegia called NTE-related motor neuron disorder (NTE-MND). Furthermore, the NTE protein from affected individuals has altered enzymological characteristics. Moreover, closely related PNPLA7 is regulated by insulin and glucose. These seemingly disparate findings are not necessarily mutually exclusive, but we need to reconcile recent genetic findings with the historical body of toxicological data indicating that inhibition and aging of NTE are both necessary in order to produce neuropathy from exposure to certain OP compounds. Solving this mystery will be satisfying in itself, but it is also an enterprise likely to pay dividends by enhancing our understanding of the physiological and pathogenic roles of the PNPLA family of proteins in neurological health and disease, including a potential role for NTE in diabetic neuropathy.
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Affiliation(s)
- Rudy J Richardson
- Toxicology Program, University of Michigan, Ann Arbor, MI 48109-2029, USA.
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Eichmann TO, Kumari M, Haas JT, Farese RV, Zimmermann R, Lass A, Zechner R. Studies on the substrate and stereo/regioselectivity of adipose triglyceride lipase, hormone-sensitive lipase, and diacylglycerol-O-acyltransferases. J Biol Chem 2012; 287:41446-57. [PMID: 23066022 DOI: 10.1074/jbc.m112.400416] [Citation(s) in RCA: 154] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Adipose triglyceride lipase (ATGL) is rate-limiting for the initial step of triacylglycerol (TAG) hydrolysis, generating diacylglycerol (DAG) and fatty acids. DAG exists in three stereochemical isoforms. Here we show that ATGL exhibits a strong preference for the hydrolysis of long-chain fatty acid esters at the sn-2 position of the glycerol backbone. The selectivity of ATGL broadens to the sn-1 position upon stimulation of the enzyme by its co-activator CGI-58. sn-1,3 DAG is the preferred substrate for the consecutive hydrolysis by hormone-sensitive lipase. Interestingly, diacylglycerol-O-acyltransferase 2, present at the endoplasmic reticulum and on lipid droplets, preferentially esterifies sn-1,3 DAG. This suggests that ATGL and diacylglycerol-O-acyltransferase 2 act coordinately in the hydrolysis/re-esterification cycle of TAGs on lipid droplets. Because ATGL preferentially generates sn-1,3 and sn-2,3, it suggests that TAG-derived DAG cannot directly enter phospholipid synthesis or activate protein kinase C without prior isomerization.
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Affiliation(s)
- Thomas O Eichmann
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
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Pang XY, Cao J, Addington L, Lovell S, Battaile KP, Zhang N, Rao JLUM, Dennis EA, Moise AR. Structure/function relationships of adipose phospholipase A2 containing a cys-his-his catalytic triad. J Biol Chem 2012; 287:35260-35274. [PMID: 22923616 DOI: 10.1074/jbc.m112.398859] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Adipose phospholipase A(2) (AdPLA or Group XVI PLA(2)) plays an important role in the onset of obesity by suppressing adipose tissue lipolysis. As a consequence, AdPLA-deficient mice are resistant to obesity induced by a high fat diet or leptin deficiency. It has been proposed that AdPLA mediates its antilipolytic effects by catalyzing the release of arachidonic acid. Based on sequence homology, AdPLA is part of a small family of acyltransferases and phospholipases related to lecithin:retinol acyltransferase (LRAT). To better understand the enzymatic mechanism of AdPLA and LRAT-related proteins, we solved the crystal structure of AdPLA. Our model indicates that AdPLA bears structural similarity to proteins from the NlpC/P60 family of cysteine proteases, having its secondary structure elements configured in a circular permutation of the classic papain fold. Using both structural and biochemical evidence, we demonstrate that the enzymatic activity of AdPLA is mediated by a distinctive Cys-His-His catalytic triad and that the C-terminal transmembrane domain of AdPLA is required for the interfacial catalysis. Analysis of the enzymatic activity of AdPLA toward synthetic and natural substrates indicates that AdPLA displays PLA(1) in addition to PLA(2) activity. Thus, our results provide insight into the enzymatic mechanism and biochemical properties of AdPLA and LRAT-related proteins and lead us to propose an alternate mechanism for AdPLA in promoting adipose tissue lipolysis that is not contingent on the release of arachidonic acid and that is compatible with its combined PLA(1)/A(2) activity.
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Affiliation(s)
- Xiao-Yan Pang
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045
| | - Jian Cao
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California San Diego, La Jolla, California 92093
| | - Linsee Addington
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045
| | - Scott Lovell
- Del Shankel Structural Biology Center, University of Kansas, Lawrence, Kansas 66047
| | - Kevin P Battaile
- Industrial Macromolecular Crystallography Association Collaborative Access Team (IMCA-CAT), Hauptman-Woodward Medical Research Institute, Argonne, Illinois 60439
| | - Na Zhang
- Del Shankel Structural Biology Center, University of Kansas, Lawrence, Kansas 66047
| | - J L Uma Maheswar Rao
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045
| | - Edward A Dennis
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California San Diego, La Jolla, California 92093
| | - Alexander R Moise
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045.
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Renvoisé B, Stadler J, Singh R, Bakowska JC, Blackstone C. Spg20-/- mice reveal multimodal functions for Troyer syndrome protein spartin in lipid droplet maintenance, cytokinesis and BMP signaling. Hum Mol Genet 2012; 21:3604-18. [PMID: 22619377 DOI: 10.1093/hmg/dds191] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Hereditary spastic paraplegias (HSPs; SPG1-48) are inherited neurological disorders characterized by lower extremity spasticity and weakness. Loss-of-function mutations in the SPG20 gene encoding spartin cause autosomal recessive Troyer syndrome (SPG20), which has additional features of short stature, cognitive deficits and distal amyotrophy. To identify cellular impairments underlying Troyer syndrome, we generated Spg20-/- mice, which exhibit progressive gait defects. Although gross central nervous system pathology appeared largely normal, cerebral cortical neurons cultured from neonatal Spg20-/- mice exhibited increased axon branching, a phenotype suppressed by reintroducing spartin and which required its interaction with the endosomal sorting complex required for transport (ESCRT)-III protein IST1. Analysis of the bone morphogenetic protein (BMP) signaling pathway in Spg20-/- embryonic fibroblasts indicated that Smad1/5 phosphorylation is modestly elevated, possibly due to alterations in BMP receptor trafficking. Cytokinesis was impaired in embryonic fibroblasts cultured from Spg20-/- mice, and binucleated chondrocytes were prominent in epiphyseal growth plates of bones in Spg20-/- mice, perhaps explaining the short stature of patients. Finally, adipose tissue from Spg20-/- female mice exhibited increased lipid droplet (LD) numbers and alterations in perilipin levels, supporting a role for spartin in LD maintenance. Taken together, our results support multimodal functions for spartin that provide important insights into HSP pathogenesis.
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Affiliation(s)
- Benoît Renvoisé
- Cell Biology Section, Neurogenetics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA
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Identification of two novel splicing variants of murine NTE-related esterase. Gene 2012; 497:164-71. [PMID: 22326266 DOI: 10.1016/j.gene.2012.01.064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2011] [Revised: 01/09/2012] [Accepted: 01/26/2012] [Indexed: 11/22/2022]
Abstract
NTE-related esterase (NRE) is an insulin-regulated lysophospholipase with homology to neuropathy target esterase (NTE), which plays a role in energy metabolism. Here, we reported two alternative splicing variants of the murine NRE (mNRE) gene, termed mNREV1 and mNREV2. Genomic organization analysis indicated that 5' splice site of mNRE intron 33 was changed in both mNREV1 and mNREV2, and mNRE exon 21 was deleted in mNREV2. mNREV1 had the same protein domains with mNRE, while mNREV2 lacked the patatin domain in the C-terminal catalytic region. Green fluorescent protein-mNREV1 or mNREV2 fusion proteins localized to the endoplasmic reticulum. mNREV1 and mNRE exhibited equal hydrolytic activity to the substrate phenyl valerate, whereas mNREV2 did not have any catalytic activity. The expression profiles of mNRE and its splicing isoforms in white adipose tissue, cardiac muscle, skeletal muscle, and testis tissues were further analyzed by real time quantitative-PCR in fed and fasted states, which indicated that the major isoform of mNRE mRNA generated switched from mNREV2 to mNREV1 during fasting. Thus there was a nutritional regulation of mNRE expression at the mRNA levels via alternative splicing.
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Degradation of mouse NTE-related esterase by macroautophagy and the proteasome. Mol Biol Rep 2012; 39:7125-31. [PMID: 22307796 DOI: 10.1007/s11033-012-1544-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 01/24/2012] [Indexed: 10/14/2022]
Abstract
NTE-related esterase (NRE) is a novel endoplasmic reticulum-anchored lysophospholipase with high homology to neuropathy target esterase (NTE). However, little is known about the regulation of NRE protein. In the current study, we investigated the degradation pathways of mouse NRE (mNRE) in mammalian cells. Based on experiments with inhibitors and inducer of protein degradation pathways, we provide here the first evidence that mNRE is degraded by macroautophagy as well as by the proteasome. Moreover, the contribution of protein domains to the degradation of mNRE was investigated, which showed that the transmembrane and regulatory domain played a role in the degradation of mNRE by macroautophagy and the proteasome respectively. In contrast the C-terminal catalytic domain was not involved in both degradation pathways of mNRE. These findings showed for the first time that the degradation pathways in controlling mNRE quantity and may provide further insight into structure and regulation of mNRE.
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Dennis EA, Cao J, Hsu YH, Magrioti V, Kokotos G. Phospholipase A2 enzymes: physical structure, biological function, disease implication, chemical inhibition, and therapeutic intervention. Chem Rev 2011; 111:6130-85. [PMID: 21910409 PMCID: PMC3196595 DOI: 10.1021/cr200085w] [Citation(s) in RCA: 804] [Impact Index Per Article: 61.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Edward A. Dennis
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Jian Cao
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Yuan-Hao Hsu
- Department of Chemistry and Biochemistry and Pharmacology, School of Medicine, University of California, San Diego, La Jolla, California 92093-0601
| | - Victoria Magrioti
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
| | - George Kokotos
- Laboratory of Organic Chemistry, Department of Chemistry, University of Athens, Panepistimiopolis, Athens 15771, Greece
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Hermansson M, Hokynar K, Somerharju P. Mechanisms of glycerophospholipid homeostasis in mammalian cells. Prog Lipid Res 2011; 50:240-57. [DOI: 10.1016/j.plipres.2011.02.004] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 02/21/2011] [Accepted: 02/25/2011] [Indexed: 01/09/2023]
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Murakami M, Taketomi Y, Miki Y, Sato H, Hirabayashi T, Yamamoto K. Recent progress in phospholipase A₂ research: from cells to animals to humans. Prog Lipid Res 2010; 50:152-92. [PMID: 21185866 DOI: 10.1016/j.plipres.2010.12.001] [Citation(s) in RCA: 368] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Mammalian genomes encode genes for more than 30 phospholipase A₂s (PLA₂s) or related enzymes, which are subdivided into several classes including low-molecular-weight secreted PLA₂s (sPLA₂s), Ca²+-dependent cytosolic PLA₂s (cPLA₂s), Ca²+-independent PLA₂s (iPLA₂s), platelet-activating factor acetylhydrolases (PAF-AHs), lysosomal PLA₂s, and a recently identified adipose-specific PLA. Of these, the intracellular cPLA₂ and iPLA₂ families and the extracellular sPLA₂ family are recognized as the "big three". From a general viewpoint, cPLA₂α (the prototypic cPLA₂ plays a major role in the initiation of arachidonic acid metabolism, the iPLA₂ family contributes to membrane homeostasis and energy metabolism, and the sPLA₂ family affects various biological events by modulating the extracellular phospholipid milieus. The cPLA₂ family evolved along with eicosanoid receptors when vertebrates first appeared, whereas the diverse branching of the iPLA₂ and sPLA₂ families during earlier eukaryote development suggests that they play fundamental roles in life-related processes. During the past decade, data concerning the unexplored roles of various PLA₂ enzymes in pathophysiology have emerged on the basis of studies using knockout and transgenic mice, the use of specific inhibitors, and information obtained from analysis of human diseases caused by mutations in PLA₂ genes. This review focuses on current understanding of the emerging biological functions of PLA₂s and related enzymes.
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Affiliation(s)
- Makoto Murakami
- Lipid Metabolism Project, The Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
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Scherer GFE, Ryu SB, Wang X, Matos AR, Heitz T. Patatin-related phospholipase A: nomenclature, subfamilies and functions in plants. TRENDS IN PLANT SCIENCE 2010; 15:693-700. [PMID: 20961799 DOI: 10.1016/j.tplants.2010.09.005] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2010] [Revised: 08/24/2010] [Accepted: 09/10/2010] [Indexed: 05/18/2023]
Abstract
The release of fatty acids from membrane glycerolipids has been implicated in a variety of cellular processes, but the enzymes involved and their regulation are poorly understood in plants. One large group of acyl-hydrolyzing enzymes is structurally related to patatins. Patatins are potato tuber proteins with acyl-hydrolyzing activity, and the patatin catalytic domain is widely spread in bacterial, yeast, plant and animal enzymes. Recent results have indicated that patatin-related enzymes are involved in different cellular functions, including plant responses to auxin, elicitors or pathogens, and abiotic stresses and lipid mobilization during seed germination. In this review, we highlight recent developments regarding these enzymes and propose the nomenclature pPLA for the patatin-related phospholipase A enzyme.
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Affiliation(s)
- Günther F E Scherer
- Leibniz Universität Hannover, Inst. f. Zierpflanzenbau & Gehölzforschung, Abt. Molekulare Ertragsphysiologie, Herrenhäuser Str. 2, D-30419 Hannover, Germany.
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Buchebner M, Pfeifer T, Rathke N, Chandak PG, Lass A, Schreiber R, Kratzer A, Zimmermann R, Sattler W, Koefeler H, Fröhlich E, Kostner GM, Birner-Gruenberger R, Chiang KP, Haemmerle G, Zechner R, Levak-Frank S, Cravatt B, Kratky D. Cholesteryl ester hydrolase activity is abolished in HSL-/- macrophages but unchanged in macrophages lacking KIAA1363. J Lipid Res 2010; 51:2896-908. [PMID: 20625037 PMCID: PMC2936755 DOI: 10.1194/jlr.m004259] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Revised: 07/12/2010] [Indexed: 12/24/2022] Open
Abstract
Cholesteryl ester (CE) accumulation in macrophages represents a crucial event during foam cell formation, a hallmark of atherogenesis. Here we investigated the role of two previously described CE hydrolases, hormone-sensitive lipase (HSL) and KIAA1363, in macrophage CE hydrolysis. HSL and KIAA1363 exhibited marked differences in their abilities to hydrolyze CE, triacylglycerol (TG), diacylglycerol (DG), and 2-acetyl monoalkylglycerol ether (AcMAGE), a precursor for biosynthesis of platelet-activating factor (PAF). HSL efficiently cleaved all four substrates, whereas KIAA1363 hydrolyzed only AcMAGE. This contradicts previous studies suggesting that KIAA1363 is a neutral CE hydrolase. Macrophages of KIAA1363(-/-) and wild-type mice exhibited identical neutral CE hydrolase activity, which was almost abolished in tissues and macrophages of HSL(-/-) mice. Conversely, AcMAGE hydrolase activity was diminished in macrophages and some tissues of KIAA1363(-/-) but unchanged in HSL(-/-) mice. CE turnover was unaffected in macrophages lacking KIAA1363 and HSL, whereas cAMP-dependent cholesterol efflux was influenced by HSL but not by KIAA1363. Despite decreased CE hydrolase activities, HSL(-/-) macrophages exhibited CE accumulation similar to wild-type (WT) macrophages. We conclude that additional enzymes must exist that cooperate with HSL to regulate CE levels in macrophages. KIAA1363 affects AcMAGE hydrolase activity but is of minor importance as a direct CE hydrolase in macrophages.
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Affiliation(s)
- Marlene Buchebner
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Thomas Pfeifer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Nora Rathke
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Prakash G. Chandak
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Achim Lass
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Renate Schreiber
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Adelheid Kratzer
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Wolfgang Sattler
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Harald Koefeler
- Center of Molecular Medicine, and Center for Medical Research, Medical University of Graz, Graz, Austria
| | - Eleonore Fröhlich
- Center of Molecular Medicine, and Center for Medical Research, Medical University of Graz, Graz, Austria
| | - Gerhard M. Kostner
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Ruth Birner-Gruenberger
- Center of Molecular Medicine, and Center for Medical Research, Medical University of Graz, Graz, Austria
| | - Kyle P. Chiang
- Skaggs Institute for Chemical Biology and Department of Chemical Physiology, Scripps Research Institute, La Jolla, CA
| | - Guenter Haemmerle
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
| | - Sanja Levak-Frank
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
| | - Benjamin Cravatt
- Skaggs Institute for Chemical Biology and Department of Chemical Physiology, Scripps Research Institute, La Jolla, CA
| | - Dagmar Kratky
- Institute of Molecular Biology and Biochemistry, Medical University of Graz, Graz, Austria
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Baulande S, Langlois C. [Proteins sharing PNPLA domain, a new family of enzymes regulating lipid metabolism]. Med Sci (Paris) 2010; 26:177-84. [PMID: 20188050 DOI: 10.1051/medsci/2010262177] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Genome sequencing technologies led to tremendous breakthrough in biology uncovering numerous genes unknown so far and thus opening the field of deep investigations to understand their associated biological functions. As a matter of fact, functional genomics have been progressively replacing sequence genomics with as a main objective to yield insight into cellular physiology. Recently, an emerging group of genes coding for proteins bearing a common domain termed patatin (PNPLA domain) have been discovered. Members of this new enzymatic family displaying lipase and transacylase properties appeared to have major roles in the regulation of lipid metabolism. The aim of this review is to make an overview on the latest discoveries concerning this new family of proteins and their relationship with lipid metabolism, physiology of mammals and their potential involvement in human pathology.
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Affiliation(s)
- Sylvain Baulande
- Recherche et Développement, Laboratoire PiLeJe, 37, quai de Grenelle, 75015 Paris, France.
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Chang PA, Wang ZX, Long DX, Qin WZ, Wu YJ. Protein domains, catalytic activity, and subcellular distribution of mouse NTE-related esterase. Mol Cell Biochem 2010; 339:181-90. [PMID: 20058052 DOI: 10.1007/s11010-009-0382-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2009] [Accepted: 06/09/2009] [Indexed: 12/21/2022]
Abstract
A mammalian family of lipid hydrolases, designated "patatin-like phospholipase domain containing (PNPLA)" recently has attracted attention. NTE-related esterase (NRE) as a member of PNPLA is an insulin-regulated lysophospholipase with homology to neuropathy target esterase (NTE). Mouse NRE (mNRE) has a predicted amino-terminal transmembrane region (TM), a putative regulatory (R) domain, and a hydrophobic catalytic (C) domain. In the current study, we described the expression of green fluorescent protein (GFP)-tagged constructs of mNRE and mutant proteins lacking the specific protein domains. Esterase assays indicated that neither the TM nor R-domain was essential for mNRE esterase activity, but the TM significantly contributed to its activity. Subcellular distribution showed that mNRE was anchored in ER via its TM domain and that its C-domain was associated with ER. Furthermore, experiments involving proteinase treatment revealed that most of mNRE molecule was exposed on the cytoplasmic face of ER membranes. Collectively, our results for the first time revealed the protein domains, catalytic activity, and subcellular location of mNRE and a simplified model for mNRE was proposed.
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Affiliation(s)
- Ping-An Chang
- Key Laboratory of Molecular Biology, College of Bio-information, Chongqing University of Posts and Telecommunications, Nan'an District, 400065 Chongqing, People's Republic of China.
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Eastman SW, Yassaee M, Bieniasz PD. A role for ubiquitin ligases and Spartin/SPG20 in lipid droplet turnover. ACTA ACUST UNITED AC 2009; 184:881-94. [PMID: 19307600 PMCID: PMC2699154 DOI: 10.1083/jcb.200808041] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
HECT (homologous to the E6AP C terminus) ubiquitin ligases have diverse functions in eukaryotic cells. In screens for proteins that bind to the HECT ubiquitin ligase WWP1, we identified Spartin, which is also known as SPG20. This protein is truncated in a neurological disease, Troyer syndrome. In this study, we show that SPG20 associates with the surface of lipid droplets (LDs) and can regulate their size and number. SPG20 binds to another LD protein, TIP47, and both proteins compete with an additional LD protein, adipophilin/adipocyte differentiation-related protein, for occupancy of LDs. The mutant SPG20 present in Troyer syndrome does not possess these activities. Depletion of SPG20 using RNA interference increases the number and size of LDs when cells are fed with oleic acid. Binding of WWP1 to SPG20 and the consequent ubiquitin transfer remove SPG20 from LDs and reduce the levels of coexpressed SPG20. These experiments suggest functions for ubiquitin ligases and SPG20 in the regulation of LD turnover and potential pathological mechanisms in Troyer syndrome.
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Affiliation(s)
- Scott W Eastman
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065, USA
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47
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Kienesberger PC, Oberer M, Lass A, Zechner R. Mammalian patatin domain containing proteins: a family with diverse lipolytic activities involved in multiple biological functions. J Lipid Res 2008; 50 Suppl:S63-8. [PMID: 19029121 DOI: 10.1194/jlr.r800082-jlr200] [Citation(s) in RCA: 233] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The human genome expresses nine patatin-like phospholipase domain containing proteins (PNPLA1-9). Members of this family share a protein domain discovered initially in patatin, the most abundant protein of the potato tuber. Patatin is a lipid hydrolase with an unusual folding topology that differs from classical lipases. Mammalian PNPLAs include lipid hydrolases with specificities for diverse substrates such as triacylglycerols, phospholipids, and retinol esters. Analysis of induced mutant mouse models and the clinical phenotype of patients with mutations revealed important insights into the physiological role of several members of the PNPLA family. This review aims to summarize current knowledge of PNPLA proteins and to document their emerging importance in lipid and energy homeostasis.
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48
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Saarela J, Jung G, Hermann M, Nimpf J, Schneider WJ. The patatin-like lipase family in Gallus gallus. BMC Genomics 2008; 9:281. [PMID: 18549477 PMCID: PMC2435558 DOI: 10.1186/1471-2164-9-281] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Accepted: 06/12/2008] [Indexed: 01/04/2023] Open
Abstract
Background In oviparous species, genes encoding proteins with functions in lipid remodeling, such as specialized lipases, may have evolved to facilitate the assembly and utilization of yolk lipids by the embryo. The mammalian gene family of patatin-like phospholipases (PNPLAs) has received significant attention, but studies in other vertebrates are lacking; thus, we have begun investigations of PNPLA genes in the chicken (Gallus gallus). Results We scanned the draft chicken genome using human PNPLA sequences, and performed PCR to amplify and sequence orthologous cDNAs. Full-length cDNA sequences of galline PNPLA2/ATGL, PNPLA4, -7, -8, -9, and the activator protein CGI-58, as well as partial cDNA sequences of avian PNPLA1, -3, and -6 were obtained. The high degree of sequence identities (~50 to 80%) between the avian and human orthologs suggests conservation of important enzymatic functions. Quantitation by qPCR of the transcript levels of PNPLAs and CGI-58 in 21 tissues indicates that expression patterns and levels diverge greatly between species. A particularly interesting tissue in which certain PNPLAs may contribute to physiological specialization is the extraembryonic yolk sac. Conclusion Knowledge about the exact in-vivo functions of PNPLAs in any system is still sparse. Thus, studies about the temporal expression patterns and functions of the enzymes identified here, and of other already known extracellular lipases and co-factors, in the yolk sac and embryonic tissues during embryogenesis are called for. Based on the information obtained, further studies are anticipated to provide important insights of the roles of PNPLAs in the yolk sac and embryo development.
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Affiliation(s)
- Jani Saarela
- The Max F. Perutz Laboratories, Department of Medical Biochemistry, Medical University of Vienna, Dr. Bohr Gasse 9/2, A-1030 Vienna, Austria.
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Schweiger M, Schoiswohl G, Lass A, Radner FP, Haemmerle G, Malli R, Graier W, Cornaciu I, Oberer M, Salvayre R, Fischer J, Zechner R, Zimmermann R. The C-terminal Region of Human Adipose Triglyceride Lipase Affects Enzyme Activity and Lipid Droplet Binding. J Biol Chem 2008; 283:17211-20. [DOI: 10.1074/jbc.m710566200] [Citation(s) in RCA: 115] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
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