Teresa Ruiz, Ph.D.

Assistant Professor

Structure/Function Studies of Eukaryotic Phosphofructokinases

Research Interest:

Glycolysis is the main pathway for energy generation in most unicellular organisms, cells lacking mitochondria (e.g. erythrocytes) and other cells when working under anaerobic conditions (e.g. muscle and cancer cells). Deficiencies and dysfunction of glycolytic enzymes, in particular phosphofructokinase, results in severe clinical syndromes and diseases (Hemolytic anemia, Tauri's disease or glycogenosis type VII, non-insulin dependent diabetes melitus and Alzheimer's disease). The first irreversible step specific of the glycolytic pathway is the phosphorylation of fructose 6-phosphate (Fru 6-P) by phosphofructokinase (Pfk-1; EC 2.7.1.11) in the presence of Mg-ATP is the. Therefore, phosphofructokinase plays a key role in the regulation of the glycolytic pathway and its activity is controlled by a large number of allosteric effectors. During the past twenty years, a large effort has been devoted to comprehend the mechanisms of catalysis and regulation of phosphofuctokinase. The information about the bacterial enzyme represents a great advancement in the understanding of this step in the glycolytic pathway, however, our knowledge on the enzyme is still limited for higher organisms. Eukaryotic phosphofructokinases not only differ in size and oligomerization state, but they also show a concentration dependent association-dissociation behavior and exhibit a far more complex regulatory mechanism due to the larger number of effectors that regulate them. Moreover, the structures of the eukaryotic enzymes are still unknown, in most cases due to the lack of good quality crystals for x-ray analysis.Our aim is to analyze the structure of phosphofructokinase from eukaryotic organisms (Saccharomyces cerevisiae, Schizosaccharomyces pombe) in the presence of different combinations of effectors and substrates by novel techniques of cryo electron microscopy of single particles and image processing, and also, fitting of x-ray models to the electron microscopy structures. Our final goal is to get a better understanding of the structure/function relationship of the mechanism of catalysis and regulation of phosphofructokinase in eukaryotic organisms.

Important Information:

UVM Practical Course on Three-dimensional Cryo Electron Microscopy of Single Particles (August 11-17, 2003)

Group Members

Montserrat Barcena (Post-doctoral Researcher)

Selected References

T. Ruiz, B. Bullard, and J. Lepault. (1998) Effects of calcium and nucleotides on the structure of insect flight muscle thin filaments. J. Muscle Research and Cell Motility 19, 353-364.

M. Radermacher, T. Ruiz, W.R. Harvey, H. Wieczorek and G. Grueber. (1999) Molecular architecture of Manduca sexta midgut V1-ATPase visualized by electron microscopy. FEBS letters. 453, 383-386.

E. Ferrary, M. Cohen-Tanoudji, G. Pehau-Arnaudet, A. Lapillonne, R. Athman, T. Ruiz, L. Boulouha, F. El Marjou, A. Doye, J-J. Fontaine, C. Antony, C. Babinet, D. Louvard, F. Jaisses, S. Robine. (1999) In vivo, villin is required for Ca2+ dependent F-actin disruption in intestinal brush-borders. J. Cell Biology. 146, 819-829.

G. Grüber, M. Radermacher, T. Ruiz, J. Godovac-Zimmermann, B. Canas., D. Kleine-Kohlbrecher, M. Huss, W. R. Harvey, H. Wieczorek. (2000) Three-dimensional structure and subunit topology of the V1 ATPase from Manduca sexta midgut. Biochemistry 39, 8609-8616.

A. Rousselet, U. Euteneuer, N. Bordes, T. Ruiz, G. Hui Bon Hua and M. Bornens. (2001) Structural and functional effects of hydrostatic pressure on centrosomes from vertebrate cells. Cell motility and the cytoskeleton. 48, 262-276.

M. Barcena, T. Ruiz , L.E. Donate, S.E. Brown, N.E. Dixon, M. Radermacher and J.M. Carazo. (2001) The DnaB•Dna C complex: a structure based on dimers assembled around and occluded channel. EMBO J. 20, 1462-1468.

J-L. Ranck, T. Ruiz, G. Pehau-Arnaudet, B. Arnoux and F. Reiss-Husson. (2001) Two-dimensional structure of the native light harvesting complex LH2 from Rubrivivax gelatinosus and of a truncated form. Biochimica and Biophysica Acta (bioenergetics), 1506, 67-78.

M. Radermacher, T. Ruiz, H. Wieczorek. and G. Grüber. (2001) The structure of the V1-ATPase determined by three-dimensional electron microscopy of single particles. Journal of Structural Biology, 135, 26-37

D. Ungar, A. Barth, W. Haase, A. Kaunzinger, E. Lewitzki, T. Ruiz, H. Reilander and H. Michel. (2001) Analysis of a putative voltage gated prokaryotic potassium channel. European Journal of Biochemistry, 268 (20): 5386-5396

T. Ruiz, G. Kopperschläger and M. Radermacher. (2001) The first three-dimensional structure of phosphofructokinase from Saccharomyces cervisiae determined by electron microscopy of single particles. Journal of Structural Biology. 136, 167-80.

K. Model, T. Prinz, T. Ruiz, M. Radermacher, T. Krimmer, W. Kühlbrandt, N. Pfanner and C. Meisinger. (2002) Protein translocase of the outer mitochondrial membrane: role of import receptors in the structural organization of the TOM complex. Journal of Molecular Biology,316, 657-666.

S. Biel, J. Simon, R. Gross, T. Ruiz, M. Ruitenberg and A. Kroger. (2002) Reconstitution of coupled fumarate respiration in liposomes by incorporating the electron transport enzymes isolated from Wolinella succinogenes. European Journal of Biochemistry. 269, 1974-83.

V.F. Rizzo, U. Cosku, M. Radermacher, T. Ruiz, A. Armbruster and G. Gruber. (2003) Resolution of the V1 ATPase from Manduca sexta into Subcomplexes and Visualization of an ATPase-active A3B3EG Complex by Electron Microscopy. J. Biol Chem 278, 270-275.