Advanced search
Start date

Understanding the mechanistic and functional details of the isozyme mammalian Liver-type glutaminase (LGA/GLS2)

Grant number: 13/05668-0
Support type:Scholarships in Brazil - Doctorate (Direct)
Effective date (Start): June 01, 2013
Effective date (End): July 31, 2015
Field of knowledge:Biological Sciences - Biochemistry
Principal Investigator:Andre Luis Berteli Ambrosio
Grantee:Igor Monteze Ferreira
Home Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia, Inovações e Comunicações (Brasil). Campinas , SP, Brazil


Firstly described by Hans Krebs one century ago, the mammalian mitochondrial glutaminases are shown as highly complexes enzymes in terms of primary sequence, creating speculations about their additional function within the cells, other than the catalytic activity over the amino acid glutamine. Mammalians have two different genes, but structurally related, that encode for at least three different isozymes known as Kidney-type Glutaminase (KGA), Glutaminase C (GAC) and Liver-type Glutaminase (LGA). One of the most important characteristics of these proteins is the differentiated expression pattern in tumoral tissues. Results obtained in our lab, published in PNAS, have demonstrated that LGA has distinct catalytic properties compared with the other glutaminases, including the way how it is changed in the presence of the activator inorganic phosphate. The LGA's primary sequence suggests the possibility that LGA can interacts with other proteins in different organelles, beyond the mitochondria and can participate directly in the gene expression regulation. Another very interesting characteristic of the glutaminases, identified by our group, is that their activation is associated with the formation of fibers, the crescent order of the activity is kept for the fiber size, in other words, GAC is the most active and shows the biggest fibers, followed by KGA, but do not form fibers. With the structure of the LGA catalytic domain solved by the student during the internship in the University of Oxford, we hope to understand better how the LGA works and to get information to build this knowledge we propose for the PhD to get more images of LGA by Electronic Microscopy and the images of some point mutants to identify which are the key residues to the no fiber formation, and we also want to study the enzymatic kinetics of the mutants. It is also proposed the construction of a chimera of LGA and GAC and obtain images of it, to know which are the critical portions in GAC that lead to the fiber formation. The crystallographic structure of the full length LGA and its C-terminal portion will be tried too. We hope these studies will contribute to get an explanation for why most of the cancer cells prefer to express GAC and KGA instead LGA. (AU)

Academic Publications
(References retrieved automatically from State of São Paulo Research Institutions)
FERREIRA, Igor Monteze. Biochemical and structural studies of the enzyme glutaminase-2 (GLS2) from mammalian. 2015. Doctoral Thesis - Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia.

Please report errors in scientific publications list by writing to: