Torres had a distinguished career as one of Argentina’s leading biological chemists.
Héctor Norberto Torres, professor emeritus at the University of Buenos Aires and founding director of Argentina’s Institute for Molecular Biology and Genetic Engineering, died on April 2 of a sudden heart attack. He was 75.
Torres, or Doc, as his students and close colleagues called him, had a distinguished career as one of Argentina’s leading biological chemists that started with his joining Nobel laureate Luis F. Leloir’s research group at the Institute of Biochemical Research, Fundación Campomar, in 1959, immediately after finishing medical school. There, Torres studied the mechanisms that regulate glycogen biosynthesis and earned a doctorate degree from the University of Buenos Aires in 1966.
Working mostly with graduate students and his lifelong collaborator and spouse, Mirtha Flawiá, in the early 1970s Torres discovered that the adenylyl cyclase-cAMP signaling system, which had recently been shown to mediate actions of peptide hormones and biogenic amines in vertebrates, also existed in the primitive fungus Neuropora crassa and proved that cAMP is a developmental cue in this organism.
After 1983, Torres focused on the molecular nature and roles of signaling pathways in the development of trypanosomes, specifically Trypanosoma cruzi, a protist that is one of the most primitive eukaryotes and is the etiologic agent of Chagas disease. Torres characterized enzymes controlling glycogen metabolism through phosphorylation/dephosphorylation mechanisms involving cyclic nucleotide phosphodiesterases, cyclic AMP and Ca/diacylglycerol stimulated protein kinase, adenylyl cyclase, nitric oxide synthase, G proteins and energy transducing systems – all possible targets of intervention to attack this parasite.
Among Torres’ later contributions are the finding that the signal by which an intermediary nonpathogenic form of T. cruzi progresses to the pathogenic form is the second messenger cAMP, generated in response to a peptide generated from globin in the hindgut of the transmitting insect; the discovery of a nitric oxide synthase in T. cruzi and the assignment of a role for nitric oxide in regulating the parasite’s motility; the discovery of phosphoarginine in T. cruzi; and the finding that the biosynthetic enzyme arginine kinase is evolutionarily related to arthropod arginine kinase, suggesting horizontal gene transfer.