Open Access. Powered by Scholars. Published by Universities.®

Molecular Biology Commons™

Open Access. Powered by Scholars. Published by Universities.®

Technological University Dublin

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 31 - 44 of 44

Full-Text Articles in Molecular Biology

Regulated Expression Of Adenoviral Vectors-Based Gene Therapies: Therapeutic Expression Of Toxins And Immune-Modulators, James Curtin, Marianela Candolfi, Mariana Puntel, Weidong Xiong, Akm Ghulam Muhammad, Kurt Kroeger, Sonali Mondkar, Chunyan Liu, Niyati Bondale, Pedro Lowenstein, Maria Castro Jan 2008

Regulated Expression Of Adenoviral Vectors-Based Gene Therapies: Therapeutic Expression Of Toxins And Immune-Modulators, James Curtin, Marianela Candolfi, Mariana Puntel, Weidong Xiong, Akm Ghulam Muhammad, Kurt Kroeger, Sonali Mondkar, Chunyan Liu, Niyati Bondale, Pedro Lowenstein, Maria Castro

Articles

Regulatable promoter systems allow gene expression to be tightly controlled in vivo. This is highly desirable for the development of safe, efficacious adenoviral vectors that can be used to treat human diseases in the clinic. Ideally, regulatable cassettes should have minimal gene expression in the "OFF" state, and expression should quickly reach therapeutic levels in the "ON" state. In addition, the components of regulatable cassettes should be non-toxic at physiological concentrations and should not be immunogenic, especially when treating chronic illness that requires long-lasting gene expression. In this chapter, we will describe in detail protocols to develop and validate first …


Novel Functions Of Acyl-Coa Thioesterases And Acyltransferases As Auxiliary Enzymes In Peroxisomal Lipid Metabolism., Mary Hunt, Stefan Alexson Jan 2008

Novel Functions Of Acyl-Coa Thioesterases And Acyltransferases As Auxiliary Enzymes In Peroxisomal Lipid Metabolism., Mary Hunt, Stefan Alexson

Articles

Peroxisomes are single membrane bound organelles present in almost all eukaryotic cells, and to date have been shown to contain approximately 60 identified enzymes involved in various metabolic pathways, including the oxidation of a variety of lipids. These lipids include very long-chain fatty acids, methyl branched fatty acids, prostaglandins, bile acid precursors, and xenobiotics that are either β-oxidized or α-oxidized in peroxisomes. The recent identification of several acyl-CoA thioesterases and acyltransferases in peroxisomes has revealed their various functions in acting as auxiliary enzymes in α- and β-oxidation in this organelle. To date, 9 functional acyl-CoA thioesterases and acyltransferases have been …


The Nudix Hydrolase 7 Is An Acyl-Coa Diphosphatase Involved In Regulating Peroxisomal Coenzyme A Homeostasis., Sarah-Jayne Reilly, Veronica Tillander, Rob Ofman, Stefan Alexson, Mary Hunt Jan 2008

The Nudix Hydrolase 7 Is An Acyl-Coa Diphosphatase Involved In Regulating Peroxisomal Coenzyme A Homeostasis., Sarah-Jayne Reilly, Veronica Tillander, Rob Ofman, Stefan Alexson, Mary Hunt

Articles

Coenzyme A (CoASH) is an obligate cofactor for lipids undergoing β-oxidation in peroxisomes. Although the peroxisomal membrane appears to be impermeable to CoASH, peroxisomes contain their own pool of CoASH. It is believed that CoASH enters peroxisomes as acyl-CoAs, but it is not known how this pool is regulated. The mouse nudix hydrolase 7 (NUDT7α) was previously identified in peroxisomes as a CoAdiphosphatase, and therefore suggested to be involved in regulation of peroxisomal CoASH levels. Here we show that mouse NUDT7α mainly acts as an acyl-CoA diphosphatase, with highest activity towards medium chain acyl-CoAs, and much lower activity with CoASH. …


Peroxisomes Contain A Specific Phytanoly-Coa/Pristanoyl-Coa Thioesterase Acting As A Novel Auxiliary Enzyme In Alpha-And Beta-Oxidation Of Methyl-Branched Fatty Acids In Mouse, Maria Westin, Mary Hunt, Stefan Alexson Jan 2007

Peroxisomes Contain A Specific Phytanoly-Coa/Pristanoyl-Coa Thioesterase Acting As A Novel Auxiliary Enzyme In Alpha-And Beta-Oxidation Of Methyl-Branched Fatty Acids In Mouse, Maria Westin, Mary Hunt, Stefan Alexson

Articles

Phytanic acid and pristanic acid are derived from phytol, which enter the body via the diet. Phytanic acid contains a methyl group in position three and therefore cannot undergo b-oxidation directly, but instead must first undergo a-oxidation to pristanic acid, which then enters b-oxidation. Both these pathways occur in peroxisomes, and in this study we have identified a novel peroxisomal acyl-CoA thioesterase, named ACOT6, which we show is specifically involved in phytanic acid and pristanic acid metabolism. Sequence analysis of ACOT6 revealed a putative peroxisomal targeting signal at the C-terminal end, and cellular localization experiments verified it as a peroxisomal …


A Peroxisomal Acyltransferase In Mouse Identifies A Novel Pathway For Taurine Conjugation Of Fatty Acids., Sarah-Jayne Reilly, Eithne O'Shea, O'Byrne James, Stefan Alexson, Mary Hunt Jan 2007

A Peroxisomal Acyltransferase In Mouse Identifies A Novel Pathway For Taurine Conjugation Of Fatty Acids., Sarah-Jayne Reilly, Eithne O'Shea, O'Byrne James, Stefan Alexson, Mary Hunt

Articles

A wide variety of endogenous carboxylic acids and xenobiotics are conjugated with amino acids, before excretion in urine or bile. The conjugation of carboxylic acids and bile acids with taurine and glycine has been widely characterized and de-novo synthesized bile acids are conjugated to either glycine or taurine in peroxisomes. Peroxisomes are also involved in the oxidation of several other lipid molecules, such as very long chain acyl-CoAs, branched chain acyl-CoAs and prostaglandins. In this study we have now identified a novel peroxisomal enzyme called acyl-CoA:amino acid N-acyltransferase (ACNAT1). Recombinantly expressed ACNAT1 acts as an acyltransferase that efficiently conjugates very …


Analysis Of The Mouse And Human Acyl-Coa Thioesterase (Acot) Gene Clusters Shows That Convergent, Functional Evolution Results In A Reduced Number Of Human Peroxisomal Acots., Mary Hunt, Anna Rautanen, Maria Westin, Thomas Svensson, Stefan Alexson Jan 2006

Analysis Of The Mouse And Human Acyl-Coa Thioesterase (Acot) Gene Clusters Shows That Convergent, Functional Evolution Results In A Reduced Number Of Human Peroxisomal Acots., Mary Hunt, Anna Rautanen, Maria Westin, Thomas Svensson, Stefan Alexson

Articles

The maintenance of cellular levels of free fatty acids and acyl-CoAs, the activated form of free fatty acids, is extremely important as imbalances in lipid metabolism have serious consequences for human health. Acyl-CoA thioesterases (ACOTs) hydrolyze acyl-CoAs to the free fatty acid and CoASH, and thereby have the potential to regulate intracellular levels of these compounds. We have previously identified and characterized a mouse ACOT gene cluster, comprised of six genes that apparently arose by gene duplications, encoding acyl- CoA thioesterases with localizations in cytosol (ACOT1), mitochondria (ACOT2) and peroxisomes (ACOT3-6). However, the corresponding human gene cluster contains only three …


Regulatable Gene Expression Systems For Gene Therapy Applications: Progress And Future Challenges, Shyam Goverdhana, Mariana Puntel, Weidong Xiong, Jeffrey Zirger, Carlos Barcia, James Curtin, Eric Soffer, Sonali Mondkar, Gwendalyn King, Jinwei Hu, Marianela Candolfi, Diane Greengold, Pedro Lowenstein, Maria Castro Aug 2005

Regulatable Gene Expression Systems For Gene Therapy Applications: Progress And Future Challenges, Shyam Goverdhana, Mariana Puntel, Weidong Xiong, Jeffrey Zirger, Carlos Barcia, James Curtin, Eric Soffer, Sonali Mondkar, Gwendalyn King, Jinwei Hu, Marianela Candolfi, Diane Greengold, Pedro Lowenstein, Maria Castro

Articles

Gene therapy aims to revert diseased phenotypes by the use of both viral and nonviral gene delivery systems. Substantial progress has been made in making gene transfer vehicles more efficient, less toxic, and nonimmunogenic and in allowing long-term transgene expression. One of the key issues in successfully implementing gene therapies in the clinical setting is to be able to regulate gene expression very tightly and consistently as and when it is needed. The regulation ought to be achievable using a compound that should be nontoxic, be able to penetrate into the desired target tissue or organ, and have a half-life …


A Revised Nomenclature For Mammalian Acyl-Coa Thioesterases/Hydrolases, Mary Hunt, Junji Yamada, Lois Maltais, Mathew Wright, Ernesto Podesta, Stefan Alexson Jun 2005

A Revised Nomenclature For Mammalian Acyl-Coa Thioesterases/Hydrolases, Mary Hunt, Junji Yamada, Lois Maltais, Mathew Wright, Ernesto Podesta, Stefan Alexson

Articles

Acyl-CoA thioesterases, also known as acyl-CoA hydrolases, are a group of enzymes that hydrolyze CoA esters such as acyl-CoAs (saturated, unsaturated, branched chain), bile acid-CoAs, CoA esters of prostaglandins etc, to the corresponding free acid and coenzyme A. There is however significant confusion regarding the nomenclature of these genes. In agreement with the HUGO Gene Nomenclature Committee (HGNC) and the Mouse Genomic Nomenclature Committee (MGNC), a revised nomenclature for mammalian acyl-CoA thioesterases/hydrolases has been suggested for the 12 member family. The family root symbol is ACOT, with human genes named ACOT1-12, and rat and mouse named Acot1-12. Several of the …


New Insights Into Bile Acid Amidation, Mary Hunt, Eithne O'Shea, Karianne Solaas, Bengt Kase, Stefan Alexson Jan 2005

New Insights Into Bile Acid Amidation, Mary Hunt, Eithne O'Shea, Karianne Solaas, Bengt Kase, Stefan Alexson

Articles

No abstract provided.


Identification Of Fatty Acid Oxidation Disorder Patients With Lowered Acyl-Coa Thioesterase Activity In Human Skin Fibroblasts, Mary Hunt, Jos Ruiter, Petra Mooyer, Carlo W T Van Roermond, Rob Ofman, Lodewig Ijlst, Ronald J A Wanders Jan 2005

Identification Of Fatty Acid Oxidation Disorder Patients With Lowered Acyl-Coa Thioesterase Activity In Human Skin Fibroblasts, Mary Hunt, Jos Ruiter, Petra Mooyer, Carlo W T Van Roermond, Rob Ofman, Lodewig Ijlst, Ronald J A Wanders

Articles

Background: Acyl-CoA thioesterases are enzymes that hydrolyze acyl-CoAs to the free fatty acid and coenzyme A (CoASH). These enzymes have been identified in several cellular compartments and are thought to regulate intracellular levels of acyl-CoAs, free fatty acids and CoASH. However, to date no patients deficient in acyl-CoA thioesterases have been identified. Design: Acyl-CoA thioesterase activity was measured in human skin fibroblasts. Western blot analysis was used to determine Type-II acyl-CoA thioesterase protein levels in patients. Results: Activity was found in human fibroblasts with all saturated acyl-CoAs from C4:0- to C18:0-CoA, with highest activity detected with lauroyl-CoA and myristoyl-CoA (C12:0 …


Isolation Of Cancer Stem Cells From Adult Glioblastoma Multiforme, Xianpeng Yuan, James Curtin, Yizhi Xiong, Gentao Liu, Sebastian Waschsmann-Hogiu, Daniel Farkas, Keith Black, John Yu Dec 2004

Isolation Of Cancer Stem Cells From Adult Glioblastoma Multiforme, Xianpeng Yuan, James Curtin, Yizhi Xiong, Gentao Liu, Sebastian Waschsmann-Hogiu, Daniel Farkas, Keith Black, John Yu

Articles

Glioblastoma multiforme (GBM) is the most common adult primary brain tumor and is comprised of a heterogeneous population of cells. It is unclear which cells within the tumor mass are responsible for tumor initiation and maintenance. In this study, we report that brain tumor stem cells can be identified from adult GBMs. These tumor stem cells form neurospheres, possess the capacity for self-renewal, express genes associated with neural stem cells (NSCs), generate daughter cells of different phenotypes from one mother cell, and differentiate into the phenotypically diverse populations of cells similar to those present in the initial GBM. Having a …


Molecular Cloning And Characterization Of Two Mouse Peroxisome Proliferator-Activated Receptor Alpha (Ppara) Regulated Peroxisomal Acyl-Coa Thioesterases., Maria Westin, Mary Hunt, Stefan Alexson Jan 2004

Molecular Cloning And Characterization Of Two Mouse Peroxisome Proliferator-Activated Receptor Alpha (Ppara) Regulated Peroxisomal Acyl-Coa Thioesterases., Maria Westin, Mary Hunt, Stefan Alexson

Articles

Peroxisomes are organelles that function in the b-oxidation of very-long and long-chain acyl-CoAs, bile acid-CoA intermediates, prostaglandins, leukotrienes, thromboxanes, dicarboxylic fatty acids, pristanic acid and xenobiotic carboxylic acids. The very long- and long-chain acyl-CoAs are mainly chain-shortened and then transported to mitochondria for further metabolism. We have now identified and characterized two peroxisomal acyl- CoA thioesterases, named PTE-Ia and PTE-Ic, which hydrolyze acyl-CoAs to the free fatty acid and coenzyme A. PTE-Ia and PTE-Ic show 82% sequence identity at amino acid level and a putative peroxisomal type 1 targeting signal of –AKL was identified at the carboxy-terminal end of both …


Characterization Of An Acyl-Coa Thioesterase That Functions As A Major Regulator Of Peroxisomal Lipid Metabolism, Mary Hunt, Karianne Solaas, Bengt F. Kase, Stefan E H Alexson Jan 2002

Characterization Of An Acyl-Coa Thioesterase That Functions As A Major Regulator Of Peroxisomal Lipid Metabolism, Mary Hunt, Karianne Solaas, Bengt F. Kase, Stefan E H Alexson

Articles

Peroxisomes function in b-oxidation of very long- and long-chain fatty acids, dicarboxylic fatty acids, bile acid intermediates, prostaglandins, leukotrienes, thromboxanes, pristanic acid and xenobiotic carboxylic acids. These lipids are mainly chain-shortened for excretion as the carboxylic acids or transported to mitochondria for further metabolism. Several of these carboxylic acids are slowly oxidized and may therefore sequester coenzyme A (CoASH). To prevent CoASH sequestration and to facilitate excretion of chain-shortened carboxylic acids, acyl-CoA thioesterases, which catalyze the hydrolysis of acyl-CoAs to the free acid and CoASH, may play important roles. We have here cloned and characterized a peroxisomal acyl-CoA thioesterase from …


The Peroxisome Proliferator-Activated Receptor Alpha (Ppar ) Regulates Bile Acid Biosynthesis., Mary Hunt, Yi-Zeng Yang, Gosta Eggertsen, Claes Carneheim, Mats Gafvels, Curt Einarsson, Stefan Alexson Sep 2000

The Peroxisome Proliferator-Activated Receptor Alpha (Ppar ) Regulates Bile Acid Biosynthesis., Mary Hunt, Yi-Zeng Yang, Gosta Eggertsen, Claes Carneheim, Mats Gafvels, Curt Einarsson, Stefan Alexson

Articles

Fibrates are a group of hypolipidemic agents which efficiently lower serum triglyceride levels by affecting the expression of many genes involved in lipid metabolism. These effects are exerted via the peroxisome proliferator-activated receptor alpha (PPARa). In addition, fibrates also lower serum cholesterol levels, suggesting a possible link between the PPARa and cholesterol metabolism. Bile acid formation represents an important pathway for elimination of cholesterol, and the sterol 12a-hydroxylase is a branch-point enzyme in the bile acid biosynthetic pathway, which determines the ratio of cholic acid to chenodeoxycholic acid. Treatment of mice for one week with the peroxisome proliferator WY-14,643 or …