Cellular glycerolipid synthesis regulation


Team of work

González Baró, María del Rosario
Principal Investigator
mgbaro@med.unlp.edu.ar
Cattaneo, Elizabeth Renee
Investigator
elizabethcattaneo@gmail.com
Pellon Maison, Magali
Investigator
magalipellon@yahoo.com.ar
Montanaro, Mauro Aldo
Investigator
mauromontanaro@yahoo.com
Henning, Maria Florencia
florhenning@yahoo.com
Investigator
Quiroga, Ivana Yoseli
Research Fellow
yoseli_quiroga@hotmail.com
Olmedo, Luciana
Becaria
luolmedo.16@hotmail.com

Soler, Sofía
Tesinista


Collaborators from other institutions

International

Coleman, Rosalind 
Department of Nutrition and Pediatrics, University of North Carolina, Chapel Hill, NC, USA

National

Ballsels, Rosa Erra 
UBA. Universidad de Buenos Aires. Buenos Aires. Argentina.

Cabrerizo, Franco
Instituto Tecnológico de Chascomús. Chascomús. Provincia de Buenos Aires. Argentina.

Abba, Martín
Centro de Investigaciones Inmunológicas Básicas y Aplicadas. Universidad Nacional de La Plata. La Plata. Provincia de Buenos Aires. Argentina.

Rabassa, Martín
Centro de Investigaciones Inmunológicas Básicas y Aplicadas. Universidad Nacional de La Plata. La Plata. Provincia de Buenos Aires. Argentina.

Lacunza, Ezequiel 
Centro de Investigaciones Inmunológicas Básicas y Aplicadas. Universidad Nacional de La Plata. La Plata. Provincia de Buenos Aires. Argentina.

Line overview

  • Role of the glycerol-3 phosphate acyltransferase in the synthesis of cellular glycerolipids.

The first step in the synthesis of glycerolipids in mammalian cells is catalyzed by glycerol-3-phosphate acyltransferase (GPAT). Four genes that encode isoforms of this enzyme have been cloned. They can be expressed in different tissues and in different subcellular sites. In fact, we are interested in the role of GPAT2; this isoform in mainly expressed in rat, mouse and human testis. We have previously demonstrated that GPAT2 is expressed mainly in sperm cells, but when this gene is overexpressed in CHO-K1 cells, the synthesis and storage of triacylglycerols and cell proliferation increase.
Our objective is to determine substrate specificity of GPAT2, and then identify its metabolites derived from its activity, promoting cell proliferation. Another objective is to know in which kind of cell in the sperm line this gene is expressed as well as to analyze this expression in different tumor cells. 
To carry out this project, we use the classical biochemical techniques such as measurement of enzymatic activities by means of radioactive substrates, isolation techniques, analysis of lipids and fatty acids. The GPAT2 protein was detected by Western blot and immunohistochemistry, and mRNA by PCR (quantitative in real time and in situ hybridization). Also, we have studied the heterologous GPAT2 overexpression in culture cells.
We have determined that GPAT2 is a gene which mRNA is only expressed in primary spermatocytes under normal conditions; it seems to be overexpressed in non differenciated tumor cells. Some metabolites derived from its enzymatic activity are rich in arachidonate, and they may function as signals for proliferation and/or cell survival.

  • Fatty acid metabolism in the outer mitochondrial membrane.

Synthesis downregulation and triacylglycerol catabolism produce serious health problems as obesity and diabetes type 2. The first and limiting step in the TAG synthesis is catalyzed by glycerol-3-phosphate acyltransferase (GPAT). The mitochondrial isoform GPAT1 is related to TAG synthesis, and its cellular localization  is related to carnitine palmitoyltransferase 1 (CPT1) that catalyzes the limiting step of fatty acid β-oxidation, and to some isoforms of acyl-CoA synthetases of long chain fatty acids (ACSL) which  reaction product is the substrate of both GPAT1 and CPT1. It was hypothesized that in mitochondria channeling of acyl-CoA substrates to biosynthetic or oxidative processes involves protein-protein interactions. Our aim is: 1) Characterize the oligomeric structure of GPAT1; 2) Analyze the role of different isoforms of ACSL and CPT1 in the supply and availability of acyl-CoA  substrates for GPAT1. In order to achieve objective 1, techniques of chemical crosslinking either in culture cells or in mitochondrias isolated from rat liver, will be used. Protein complexes, containing GPAT1 by immunoprecipitation, will be isolated in order to identify the interacting proteins by mass spectrometry. Concerning objective 2,  we will study the reciprocal regulation of GPAT1 and CPT1 overexpressing  inactive mutants of these enzymes in cell culture, as well as substrate channeling  from different ACSL isoforms  in models of overexpression, subexpression  and inactivation of each isoform localized by GPAT1 and CPT1. Direct interaction of GPAT1 and CPT1 with ACSL will be tested by labeling transfer or Western blotting. The present studies will get insight into synthesis regulation and lipid degradation: how protein-protein interactions regulate substrate flow and products in mitochondria.  Also, certain pathological conditions concerning obesity and diabetes mellitus type 2 that lead, in part, to the metabolic syndrome, will be elucidated. 

 

Publications

 

  • Methylation of the Gpat2 promoter regulates transient expression during mouse spermatogenesis.
    García Fabiani, M. B; Montanaro, M. A; Lacunza, E; Cattaneo, E. R; Coleman, R. A; Pellon Maison, M; Gonzalez-Baró; M. R.
    2015.
    Biochemical Journal. , Londres: PORTLAND PRESS LTD, vol. 471, p. 211-220. ISSN 0264-6021

  • Glycerol-3-phosphate acyltranferase-2 behaves as a cancer testis gene and promotes growth and tumorigenicity of the breast cancer mda-mb-231 cellline. 
    Pellon Maison, M; Montanaro, M. A; Lacunza, E; Garcia Fabiani, M. B; Soler, M; Cattaneo, E; Quiroga, I. Y; Abba, M; Coleman, R; Gonzalez Baro, M del R. 
    2014. Plos one. , San Francisco: PUBLIC LIBRARY SCIENCE,. vol. 9, ISSN 1932-6203


  • Apolipoprotein A-I Helsinki promotes intracellular acyl-CoA cholesterol acyltransferase (ACAT) protein accumulation.
    Toledo, J. D; Garda, H. A; Cabaleiro, L. V; Cuellar, A; Pellón Maison, M; González Baró, M; Gonzalez M. C. 
    2013. Molecular and cellular biochemistry. , New York: SPRINGER. vol. 377, n° 1-2, p. 197-205. ISSN 0300-8177
  • Rol de la isoforma 2 de la glicerol-3-fosfato aciltransfersa 2 en el metabolismo lipídico testicular.
    Cattaneo, E. R; Pellon Maison, M; Gonzalez-Baro, M. R. 
    2013. Acta Bioquímica Clínica Latinoamericana. , La Plata: Federación Bioquímica Provincia Buenos Aires, vol. 47, p. 315-325. ISSN 0325-2957
  • Glycerol-3-Phosphate Acyltransferase-2 Is Expressed in. 
    Cattaneo, E. R; Pellon Maison, M; Rabassa, M. E; Lacunza, E; Coleman, R. A; González-Baro, M. R.
    2012. Plos One. , San Francisco: Public Library Science, vol. 7, p. 1-11


  • Photosensitization of DNA by bcarbolines: Kinetic analysis and Organic Biomolecular Chemistry.
    González, M. M; Vignoni, M; Pellon-Maison, M; Ales-Gandolfo, M. A; González-Baro, M. R; Erra-Balsells, R; Bernd Epe; Cabrerizo, F. M. 
    2012. Cambridge: Royal Soc Chemistry, vol. 10, p. 1807-1819


  • Nuclear receptors and hepatic lipidogenic enzymes response to a dyslipidemic sucrose rich diet and its revertion by fish oil n-3 polyunsaturated fatty acids. 
    Hein, G. J; Bernasconi, A.M; Montanaro, M.A; Pellon-Maison M; Finarelli, G.S; Chicco, A; Lombardo,Y. B; Brenner, R. R. 
    2010American journal of physiology-endocrinology and metabolism. Amer Physiological Soc. vol. 298, p. 429-439
  • Photosensitized cleavage of plasmidic DNA by norharmane, a naturally occurring beta-carboline.
    González, M. M; Pellon-Maison, M; Ales-Gandolfo, M. A; González-Baro, M. R; Erra-Balsells, R; Cabrerizo, F. M. 
    2010. Organic & biomolecular chemistry. Royal Soc Chemistry. vol.8, p. 2543 - 2552
  • Macrobrachium borellii hepatopancreas contains a mitochondrial glycerol-3-phosphate acyltransferase which initiates triacylglycerol biosynthesis. 
    Pellon Maison, M; García, F; Cattaneo, E; Coleman, R. A; González-Baro, M. R. 
    2009. Lipids. AOCS Press, vol. 44, p. 337-344
  • Cloning and functional characterization of a novel mitochondrial Nethylmaleimide-sensitive glycerol-3-phosphate acyltransferase (GPAT2). 
    Wang, S; Lee, D. P; Gong, N; Schwerbrock, N. M. J; Mashek. D. G; González - Baro, M. R; Stapleton, C; Li, L. O; Lewin, T. M; Coleman, R. A. 
    2007
    . Archives of biochemistry and biophysics. Elsevier. vol. 465, p. 347-358
  • Role of liver X receptor, insulin and peroxisome proliferator activated receptor alpha on in vivo desaturase modulation of unsaturated fatty acid biosynthesis. 
    Montanaro, M. A; González, M. S; Bernasconi, A. M; Brenner, R. R. 
    2007. Lipids. American Oil Chemists Society. vol. 42, p. 197-210
  • Mitochondrial glycerol-3-P acyltransferase 1 is most active in outer mitochondrial membrane but not in mitochondrial associated vesicles (MAV). 
    Pellon-Maison, M; Montanaro, M. A; Coleman, R. A; Gonzalez-Baró M. R. 
    2007. Biochimica et biophysica acta-molecular and cell biology of lipids. Elsevier. vol. 1771, p. 830-838
Book - Book chapters

  • Lipid Synthesis and Transport in Shrimps.
    Garcia, C. F; Gonzalez-Baró, M. 
    2013. Hauppauge, NY: Nova Science Publishers, p. 71-94. ISBN 978-1-62417-317-2




INIBIOLP - Instituto de Investigaciones Bioquímicas de La Plata "Profesor Doctor Rodolfo R. Brenner"
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