Giuseppe Attardi; unveiled how the engines of cells work
LOS ANGELES - Dr. Giuseppe Attardi, a geneticist who played a key role in illuminating the function of mitochondria and who linked mutations in mitochondrial DNA to the aging process, has died. He was 84.
Dr. Attardi died Saturday at his home in Altadena. The California Institute of Technology, where he worked and taught, announced the death without specifying its cause.
Mitochondria are tiny organelles within every cell of the body that convert the energy in food into a form of chemical energy, called adenosine triphosphate, or ATP, that can be used by the cell.
They thus provide the energy for everything from whacking a tennis ball to contemplating the nature of the universe.
Until the work of Dr. Attardi and others in the 1960s and 1970s, however, little was known about how they functioned.
It was known that mitochondria were the only sites outside the nucleus of the cell that contained DNA, the genetic blueprint for life. This DNA is inherited only from the mother, and researchers now often use it to trace the genetic history of individuals and groups.
Dr. Attardi was the first to show that mitochondrial DNA, also known as mtDNA, was functional, producing messenger RNA that was used to manufacture proteins.
He isolated and identified the messenger RNA produced from each of the 37 mitochondrial genes and the proteins that were produced from it, said Caltech biologist David Chan, his friend and colleague. He showed "what the products of the mitochondrial genome were," Chan said.
Dr. Attardi also played a crucial part in showing how mutations in mtDNA contribute to disease. Before his work, it was impossible to separate the contributions of such mutations from those of mutations in DNA in the nucleus.
He developed a technique for stripping the mtDNA out of a healthy cell, then replacing it with the corresponding DNA from cells of a sick patient. He could then determine how the mutations in mtDNA affected the functions of the cell.
In this way, he was able to show that a rare form of dementia now known as MELAS syndrome - or mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes - was caused solely by mutations in mtDNA.
Other researchers have subsequently used the same technique to prove that a variety of other congenital disorders are produced by mutations in mtDNA.
Researchers have speculated that declines in the functioning of mitochondria over time prompt a decline in the chemical energy available to cells, thus leading to the effects of aging.
In 2003, Dr. Attardi found that a rare inherited mutation in mtDNA is associated with a longer life. This mutation could provide a survival advantage by speeding the replication of mtDNA, allowing aging cells that carry it to produce more energy than those that do not.
Guiseppe Attardi was born Sept. 14, 1923, in Vicari, Italy, in the province of Palermo. Although he was in Italy during World War II, he avoided being drafted into Mussolini's army because he was in medical school at the University of Padua, where he received his degree in 1947. He remained on the faculty there for 10 years.
As a Fulbright Fellow, he also spent time at the Karolinska Institutet in Stockholm and the Washington University School of Medicine in St. Louis.
He joined the Caltech staff in 1959 and remained there for the rest of his career, running a productive laboratory until last summer. He became a US citizen in 1974.
According to his wife, Anne Chomyn, he was interested in art and in classical and ethnic music. He was also an avid mountain hiker. He climbed Mount Whitney as late as the 1970s, she said, and the couple hiked the Alps in the 1990s.
"One of the things I will always remember about him was his constant excitement for all types of biological questions," Chan said. "I think his intense curiosity was one reason he accomplished so much as a scientist."
Biochemist Gottfried Schatz of the University of Basel's Biozentrum in Switzerland added that Dr. Attardi "embodied a vanishing breed of scientists whom I would define as 'gentlemen intellectuals.' He had a superb grasp of European history and world culture, had mastered French and German at a very high level of proficiency, and even in his most spirited discussions refrained from personal invective or overt aggression."
In addition to his wife, a senior research fellow emeritus at Caltech, Dr. Attardi leaves a son, Luigi, of Rome; a daughter, Laura of Palo Alto; and a grandson.
