Possible regulatory roles of ATP:citrate lyase, malic enzyme, and AMP deaminase in lipid accumulation by Rhodosporidium toruloides CBS 14

1985 ◽  
Vol 31 (11) ◽  
pp. 1000-1005 ◽  
Author(s):  
Christopher Thomas Evans ◽  
Colin Ratledge
Keyword(s):  
Lipid Accumulation ◽  
Malic Enzyme ◽  
Energy Charge ◽  
Molecular Size ◽  
Rhodosporidium Toruloides ◽  
Regulatory Control ◽  
Central Position ◽  
Amp Deaminase ◽  
Atp:Citrate Lyase

The properties of ATP:citrate lyase, malic enzyme, and AMP deaminase have been investigated in Rhodosporidium toruloides CBS 14. ATP:citrate lyase had a molecular size of 480 000 daltons and apparent Km for citrate and ATP of 0.19 mM and 0.15 mM, respectively. The enzyme was inhibited by ADP, glucose 6-phosphate, palmitoyl-CoA, and oleoyl-CoA. [Formula: see text] ions showed a 95% stimulation of activity at nonsaturating concentrations (0.1 mM) of citrate. Malic enzyme had a molecular size of 205 000 daltons and an apparent Km for malate of 0.7 mM. The enzyme was only weakly inhibited by citrate, pyruvate, oxaloacetate, and ATP but no metabolite was found which exerted a significant regulatory control over the enzyme. However this enzyme could be used as the principal, if not sole, source of NADPH needed for fatty acid biosynthesis. The role of this enzyme and the central position of malate as a key metabolite in determining how lipid accumulation could be initiated and then sustained is discussed. AMP deaminase was detected in low activities but was fourfold higher in nitrogen-limited cells. The possible role of this enzyme in degrading AMP, regulating cellular energy charge, and supplementing [Formula: see text] pools in this yeast is also discussed.

scholarly journals The role of malic enzyme in the regulation of lipid accumulation in filamentous fungi

Microbiology ◽  
1999 ◽  
Vol 145 (8) ◽  
pp. 1911-1917 ◽  
Author(s):  
James P. Wynn ◽  
Aidil bin Abdul Hamid ◽  
Colin Ratledge
Keyword(s):  
Filamentous Fungi ◽  
Lipid Accumulation ◽  
Malic Enzyme

The role of ATP citrate lyase, malic enzyme and fatty acid synthase in the regulation of lipid accumulation in Cunninghamella sp. 2A1

2010 ◽  
Vol 61 (3) ◽  
pp. 463-468 ◽  
Author(s):  
Aidil Abdul Hamid ◽  
Noor Fatmawati Mokhtar ◽  
Ekhlass M. Taha ◽  
Othman Omar ◽  
Wan Mohtar Wan Yusoff
Keyword(s):  
Fatty Acid ◽  
Lipid Accumulation ◽  
Malic Enzyme ◽  
Fatty Acid Synthase ◽  
Atp Citrate Lyase ◽  
Citrate Lyase

scholarly journals Regulation of ‘malic’ enzyme of Solanum tuberosum by metabolites

1974 ◽  
Vol 137 (1) ◽  
pp. 45-53 ◽  
Author(s):  
D. D. Davies ◽  
K. D. Patil
Keyword(s):  
Solanum Tuberosum ◽  
Malic Enzyme ◽  
Energy Charge ◽  
Dicarboxylic Acids ◽  
Oxidative Decarboxylation ◽  
Bivalent Cation ◽  
Ph Values ◽  
Rate Versus ◽  
Reductive Carboxylation

A purification of ‘malic’ enzyme from potato is described. The purified enzyme is specific for NADP and requires a bivalent cation for activity. At pH values below 7 the plot of rate versus malate concentration approximates to normal Michaelis–Menten kinetics. At pH values above 7 the plot of rate versus malate concentration is sigmoid. A number of dicarboxylic acids activate the enzyme and remove the sigmoidicity. The enzyme is inhibited by phosphate, triose phosphates and AMP. In general, effectors of the oxidative decarboxylation of malate behave in the same manner in the reductive carboxylation of pyruvate. The response of the enzyme to energy charge is reported and the physiological significance of the response to metabolites is discussed in relation to the proposed role of the enzyme in the control of pH.

scholarly journals The Role of Lipids, Lipid Metabolism and Ectopic Lipid Accumulation in Axon Growth, Regeneration and Repair after CNS Injury and Disease

Cells ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1078
Author(s):  
Debasish Roy ◽  
Andrea Tedeschi
Keyword(s):  
Nervous System ◽  
Lipid Metabolism ◽  
Lipid Accumulation ◽  
Axon Regeneration ◽  
Axon Growth ◽  
The Body ◽  
Cns Repair ◽  
Cord Injury ◽  
Cns Trauma

Axons in the adult mammalian nervous system can extend over formidable distances, up to one meter or more in humans. During development, axonal and dendritic growth requires continuous addition of new membrane. Of the three major kinds of membrane lipids, phospholipids are the most abundant in all cell membranes, including neurons. Not only immature axons, but also severed axons in the adult require large amounts of lipids for axon regeneration to occur. Lipids also serve as energy storage, signaling molecules and they contribute to tissue physiology, as demonstrated by a variety of metabolic disorders in which harmful amounts of lipids accumulate in various tissues through the body. Detrimental changes in lipid metabolism and excess accumulation of lipids contribute to a lack of axon regeneration, poor neurological outcome and complications after a variety of central nervous system (CNS) trauma including brain and spinal cord injury. Recent evidence indicates that rewiring lipid metabolism can be manipulated for therapeutic gain, as it favors conditions for axon regeneration and CNS repair. Here, we review the role of lipids, lipid metabolism and ectopic lipid accumulation in axon growth, regeneration and CNS repair. In addition, we outline molecular and pharmacological strategies to fine-tune lipid composition and energy metabolism in neurons and non-neuronal cells that can be exploited to improve neurological recovery after CNS trauma and disease.

Effect of creating a fed-batch like condition using carbon to nitrogen ratios on lipid accumulation in Rhodosporidium toruloides-1588

2021 ◽  
pp. 125354
Author(s):  
Rahul Saini ◽  
Carlos Saul Osorio-Gonzalez ◽  
Krishnamoorthy Hegde ◽  
Satinder Kaur Brar ◽  
Pierre Vezina
Keyword(s):  
Lipid Accumulation ◽  
Rhodosporidium Toruloides ◽  
Fed Batch

Role of long interspersed nuclear element-1 in the regulation of chromatin landscapes and genome dynamics

2021 ◽  
pp. 153537022110312
Author(s):  
Kenneth S Ramos ◽  
Pasano Bojang ◽  
Emma Bowers
Keyword(s):  
Cancer Biology ◽  
Mobile Element ◽  
Cancer Diagnostics ◽  
Regulatory Control ◽  
Full Potential ◽  
Genome Dynamics ◽  
Human Illness ◽  
Cancer Types ◽  
Stressful Environments

LINE-1 retrotransposon, the most active mobile element of the human genome, is subject to tight regulatory control. Stressful environments and disease modify the recruitment of regulatory proteins leading to unregulated activation of LINE-1. The activation of LINE-1 influences genome dynamics through altered chromatin landscapes, insertion mutations, deletions, and modulation of cellular plasticity. To date, LINE-1 retrotransposition has been linked to various cancer types and may in fact underwrite the genetic basis of various other forms of chronic human illness. The occurrence of LINE-1 polymorphisms in the human population may define inter-individual differences in susceptibility to disease. This review is written in honor of Dr Peter Stambrook, a friend and colleague who carried out highly impactful cancer research over many years of professional practice. Dr Stambrook devoted considerable energy to helping others live up to their full potential and to navigate the complexities of professional life. He was an inspirational leader, a strong advocate, a kind mentor, a vocal supporter and cheerleader, and yes, a hard critic and tough friend when needed. His passionate stand on issues, his witty sense of humor, and his love for humanity have left a huge mark in our lives. We hope that that the knowledge summarized here will advance our understanding of the role of LINE-1 in cancer biology and expedite the development of innovative cancer diagnostics and treatments in the ways that Dr Stambrook himself had so passionately envisioned.

scholarly journals Localisation and regulation of cholesterol transporters in the human hair follicle: mapping changes across the hair cycle

2021 ◽  
Author(s):  
Megan A. Palmer ◽  
Eleanor Smart ◽  
Iain S. Haslam
Keyword(s):  
Hair Follicle ◽  
Human Hair ◽  
Vital Role ◽  
Transport Proteins ◽  
Hair Follicles ◽  
Regulatory Control ◽  
Cholesterol Transport ◽  
Hair Cycle ◽  
Human Hair Follicle

AbstractCholesterol has long been suspected of influencing hair biology, with dysregulated homeostasis implicated in several disorders of hair growth and cycling. Cholesterol transport proteins play a vital role in the control of cellular cholesterol levels and compartmentalisation. This research aimed to determine the cellular localisation, transport capability and regulatory control of cholesterol transport proteins across the hair cycle. Immunofluorescence microscopy in human hair follicle sections revealed differential expression of ATP-binding cassette (ABC) transporters across the hair cycle. Cholesterol transporter expression (ABCA1, ABCG1, ABCA5 and SCARB1) reduced as hair follicles transitioned from growth to regression. Staining for free cholesterol (filipin) revealed prominent cholesterol striations within the basement membrane of the hair bulb. Liver X receptor agonism demonstrated active regulation of ABCA1 and ABCG1, but not ABCA5 or SCARB1 in human hair follicles and primary keratinocytes. These results demonstrate the capacity of human hair follicles for cholesterol transport and trafficking. Future studies examining the role of cholesterol transport across the hair cycle may shed light on the role of lipid homeostasis in human hair disorders.

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