The genetic requirements of fatty acid import by Mycobacterium tuberculosis within macrophages

Abstract Diatoms are the dominant phytoplankton in temperate oceans and coastal regions and yet little is known about the genetic basis underpinning their global success. Here, we address this challenge by developing the first phenomic approach for a diatom, screening a collection of randomly mutagenized but identifiably tagged transformants. Based upon their tolerance to temperature extremes, several compromised mutants were identified revealing genes either stress related or encoding hypothetical proteins of unknown function. We reveal one of these hypothetical proteins is a novel putative chloroplast fatty acid transporter whose loss affects several fatty acids including the two omega-3, long-chain polyunsaturated fatty acids - eicosapentaenoic and docosahexaenoic acid, both of which have medical importance as dietary supplements and industrial significance in aquaculture and biofuels. This mutant phenotype not only provides new insights into the fatty acid biosynthetic pathways in diatoms but also highlights the future value of phenomics for revealing specific gene functions in these ecologically important phytoplankton.

Download Full-text

The RabGAPs TBC1D1 and TBC1D4 control uptake of long-chain fatty acids into skeletal muscle via fatty acid transporter SLC27A4/FATP4 Short title: RabGAPs in skeletal muscle lipid metabolism

10.2337/figshare.12857771 ◽

2020 ◽

Author(s):

Ada Admin ◽

Tim Benninghoff ◽

Lena Espelage ◽

Samaneh Eickelschulte ◽

Isabel Zeinert ◽

...

Keyword(s):

Skeletal Muscle ◽

Fatty Acids ◽

Fatty Acid ◽

Lipid Metabolism ◽

Long Chain Fatty Acids ◽

Muscle Lipid ◽

Skeletal Muscle Lipid ◽

Fatty Acid Transporter ◽

Acid Transporter ◽

Long Chain

The two closely related RabGTPase-activating proteins (RabGAPs) TBC1D1 and TBC1D4 play a crucial role in the regulation of GLUT4 translocation in response to insulin and contraction in skeletal muscle. In mice, deficiency in one or both RabGAPs leads to reduced insulin and contraction-stimulated glucose uptake, and to elevated fatty acid uptake and oxidation in both glycolytic and oxidative muscle fibers without altering mitochondrial copy number and the abundance of OXPHOS proteins. Here we present evidence for a novel mechanism of skeletal muscle lipid utilization involving the two RabGAPs and the fatty acid transporter SLC27A4/FATP4. Both RabGAPs control the uptake of saturated and unsaturated long-chain fatty acids (LCFAs) into skeletal muscle and knockdown of a subset of RabGAP substrates, Rab8, Rab10 or Rab14, decreased LCFA uptake into these cells. In skeletal muscle from Tbc1d1/Tbc1d4 knockout animals, SLC27A4/FATP4 abundance was increased and depletion of SLC27A4/FATP4 but not FAT/CD36 completely abrogated the enhanced fatty acid oxidation in RabGAP-deficient skeletal muscle and cultivated C2C12 myotubes. Collectively, our data demonstrate that RabGAP-mediated control of skeletal muscle lipid metabolism converges with glucose metabolism at the level of downstream RabGTPases and involves regulated transport of LCFAs via SLC27A4/FATP4.

Download Full-text

THE ENZYMATIC ESTERIFICATION OF ETHANOL WITH FATTY ACIDS

Canadian Journal of Biochemistry ◽

10.1139/o65-134 ◽

1965 ◽

Vol 43 (8) ◽

pp. 1223-1233 ◽

Cited By ~ 25

Author(s):

W. H. Newsome ◽

J. B. M. Rattray

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Enzymatic Esterification ◽

Fatty Acid Substrate ◽

Ethanol Level ◽

General Order ◽

Ph Range ◽

High Ethanol ◽

Acid Substrate ◽

Factor Governing

Some characteristics of the system present in pancreatin responsible for the enzymatic esterification of ethanol with fatty acids were examined. Definite pH optima were found for different fatty acids in the pH range 5.5–6.1. At a relatively high ethanol level and with a low fixed fatty acid concentration at pH 6.1, the degree of esterification was oleic = linolenic > linoleic > arachidonic > myristic > palmitic > stearic. At various acid concentrations the same general order of specificity was observed but to differing extents. The physical state of dispersion of the fatty acid in the incubation medium appeared to be a major factor governing the fatty acid specificity for esterification of ethanol. Evidence for the possible occurrence of more than one enzyme activity functioning on fatty acid substrate in different dispersion states was obtained and discussed.

Download Full-text

Rv3723/LucA coordinates fatty acid and cholesterol uptake in Mycobacterium tuberculosis

eLife ◽

10.7554/elife.26969 ◽

2017 ◽

Vol 6 ◽

Cited By ~ 50

Author(s):

Evgeniya V Nazarova ◽

Christine R Montague ◽

Thuy La ◽

Kaley M Wilburn ◽

Neelima Sukumar ◽

...

Keyword(s):

Fatty Acids ◽

Mycobacterium Tuberculosis ◽

Fatty Acid ◽

Pathogenic Bacteria ◽

Fatty Acid Uptake ◽

Bacterial Virulence ◽

Acid Uptake ◽

Uncharacterized Protein ◽

Fatty Acid Transporter

Pathogenic bacteria have evolved highly specialized systems to extract essential nutrients from their hosts. Mycobacterium tuberculosis (Mtb) scavenges lipids (cholesterol and fatty acids) to maintain infections in mammals but mechanisms and proteins responsible for the import of fatty acids in Mtb were previously unknown. Here, we identify and determine that the previously uncharacterized protein Rv3723/LucA, functions to integrate cholesterol and fatty acid uptake in Mtb. Rv3723/LucA interacts with subunits of the Mce1 and Mce4 complexes to coordinate the activities of these nutrient transporters by maintaining their stability. We also demonstrate that Mce1 functions as a fatty acid transporter in Mtb and determine that facilitating cholesterol and fatty acid import via Rv3723/LucA is required for full bacterial virulence in vivo. These data establish that fatty acid and cholesterol assimilation are inexorably linked in Mtb and reveals a key function for Rv3723/LucA in in coordinating thetransport of both these substrates.

Download Full-text

The RabGAPs TBC1D1 and TBC1D4 Control Uptake of Long-Chain Fatty Acids Into Skeletal Muscle via Fatty Acid Transporter SLC27A4/FATP4

Diabetes ◽

10.2337/db20-0180 ◽

2020 ◽

Vol 69 (11) ◽

pp. 2281-2293 ◽

Cited By ~ 1

Author(s):

Tim Benninghoff ◽

Lena Espelage ◽

Samaneh Eickelschulte ◽

Isabel Zeinert ◽

Isabelle Sinowenka ◽

...

Keyword(s):

Skeletal Muscle ◽

Fatty Acids ◽

Fatty Acid ◽

Long Chain Fatty Acids ◽

Fatty Acid Transporter ◽

Acid Transporter ◽

Long Chain ◽

Chain Fatty Acids

Download Full-text

Steryl ester formation and accumulation in steroid-degrading bacteria

10.1101/775916 ◽

2019 ◽

Author(s):

Johannes Holert ◽

Kirstin Brown ◽

Ameena Hashimi ◽

Lindsay D. Eltis ◽

William W. Mohn

Keyword(s):

Mycobacterium Tuberculosis ◽

Fatty Acid ◽

Lipid Droplets ◽

Steryl Ester ◽

Biotechnological Production ◽

Fatty Acid Substrate ◽

Adverse Conditions ◽

Steryl Esters ◽

Ester Formation ◽

Acid Substrate

ABSTRACTSteryl esters (SEs) are important storage compounds in many eukaryotes and are often prominent components of intracellular lipid droplets. Here we demonstrate that selected Actino- and Proteobacteria growing on sterols are also able to synthesize SEs and to sequester them in cytoplasmic lipid droplets. We found cholesteryl ester (CE) formation in members of the actinobacterial genera Rhodococcus, Mycobacterium, and Amycolatopsis as well as several members of the proteobacterial Cellvibrionales order. CEs maximally accumulated under nitrogen-limiting conditions, suggesting that steryl ester formation plays a crucial role for storing excess energy and carbon under adverse conditions. Rhodococcus jostii RHA1 was able to synthesize phytosteryl- and cholesteryl esters, the latter reaching up to 7% of its cellular dry weight and 69% of its lipid droplets. Purified lipid droplets from RHA1 contained CEs, free cholesterol and triacylglycerols. In addition, we found formation of CEs in Mycobacterium tuberculosis when grown with cholesterol plus an additional fatty acid substrate. This study provides a basis for the application of bacterial whole cell systems in the biotechnological production of SEs for use in functional foods and cosmetics.IMPORTANCEOleaginous bacteria exhibit great potential for the production of high-value neutral lipids, such as triacylglycerols and wax esters. This study describes the formation of steryl esters (SEs) as neutral lipid storage compounds in sterol-degrading oleaginous bacteria, providing a basis for biotechnological production of SEs using bacterial systems with potential applications in the functional food, nutraceutical, and cosmetic industries. We found cholesteryl ester (CE) formation in several sterol-degrading Actino- and Proteobacteria under nitrogen limiting conditions, suggesting an important role of this process in storing energy and carbon under adverse conditions. In addition, Mycobacterium tuberculosis grown on cholesterol accumulated CEs in the presence of an additional fatty acid substrate.

Download Full-text

The RabGAPs TBC1D1 and TBC1D4 control uptake of long-chain fatty acids into skeletal muscle via fatty acid transporter SLC27A4/FATP4 Short title: RabGAPs in skeletal muscle lipid metabolism

10.2337/figshare.12857771.v1 ◽

2020 ◽

Author(s):

Ada Admin ◽

Tim Benninghoff ◽

Lena Espelage ◽

Samaneh Eickelschulte ◽

Isabel Zeinert ◽

...

Keyword(s):

Skeletal Muscle ◽

Fatty Acids ◽

Fatty Acid ◽

Lipid Metabolism ◽

Long Chain Fatty Acids ◽

Muscle Lipid ◽

Skeletal Muscle Lipid ◽

Fatty Acid Transporter ◽

Acid Transporter ◽

Long Chain

The two closely related RabGTPase-activating proteins (RabGAPs) TBC1D1 and TBC1D4 play a crucial role in the regulation of GLUT4 translocation in response to insulin and contraction in skeletal muscle. In mice, deficiency in one or both RabGAPs leads to reduced insulin and contraction-stimulated glucose uptake, and to elevated fatty acid uptake and oxidation in both glycolytic and oxidative muscle fibers without altering mitochondrial copy number and the abundance of OXPHOS proteins. Here we present evidence for a novel mechanism of skeletal muscle lipid utilization involving the two RabGAPs and the fatty acid transporter SLC27A4/FATP4. Both RabGAPs control the uptake of saturated and unsaturated long-chain fatty acids (LCFAs) into skeletal muscle and knockdown of a subset of RabGAP substrates, Rab8, Rab10 or Rab14, decreased LCFA uptake into these cells. In skeletal muscle from Tbc1d1/Tbc1d4 knockout animals, SLC27A4/FATP4 abundance was increased and depletion of SLC27A4/FATP4 but not FAT/CD36 completely abrogated the enhanced fatty acid oxidation in RabGAP-deficient skeletal muscle and cultivated C2C12 myotubes. Collectively, our data demonstrate that RabGAP-mediated control of skeletal muscle lipid metabolism converges with glucose metabolism at the level of downstream RabGTPases and involves regulated transport of LCFAs via SLC27A4/FATP4.

Download Full-text

Neonatal fatty acid profiles are correlated with infant growth measures at 6 months

Journal of Developmental Origins of Health and Disease ◽

10.1017/s2040174417000150 ◽

2017 ◽

Vol 8 (4) ◽

pp. 474-482 ◽

Cited By ~ 3

Author(s):

P. F. O’Tierney-Ginn ◽

D. Davina ◽

M. Gillingham ◽

D. J. P. Barker ◽

C. Morris ◽

...

Keyword(s):

Fatty Acids ◽

Fatty Acid ◽

Weight Gain ◽

Lean Mass ◽

Skinfold Thickness ◽

Infant Growth ◽

Growth Patterns ◽

Fatty Acid Profiles ◽

Fatty Acid Transporter ◽

Acid Transporter

Rapid weight gain in infancy and low levels of n-3 long chain polyunsaturated fatty acids (LCPUFA) at birth are associated with increased adiposity later in life. The association between placental LCPUFA delivery and weight gain in infancy is poorly understood. We sought to determine the relationships between maternal phenotype, placental fatty acid transporter expression and offspring growth patterns over the first 6 months. Placental tissue and cord blood were collected at term delivery from women with uncomplicated pregnancies. Offspring body composition measurements were recorded 1 day and 6 months after birth. Body mass index (BMI) z-scores were determined using World Health Organization 2006 reference data. Body phenotype patterns were compared among offspring who had an increase in BMI z-score and those who had a decrease. High skinfold thickness at birth and positive change in BMI z-scores during infancy were associated with low neonatal n-3 LCPUFA plasma levels (r=−0.46, P=0.046) and high saturated fatty acids levels (r=0.49, P=0.034). Growth of skinfolds over 6 months of age was associated with placental fatty acid transporter gene expression. Change in BMI z-score in the first 6 months of life correlated with arm muscle area growth, a measure of lean mass (r=0.62, P=0.003), but not with growth in skinfold thickness. Early infancy weight gain was associated with poor plasma LCPUFA status at birth, and fat deposition in infancy was related to changes in placental lipid handling. Thus, neonatal fatty acid profiles may influence the trajectory of infant growth and fat and lean mass deposition.

Download Full-text