Noted HIV Researcher Joins Scripps Florida Faculty

Eric Sauter

The Scripps Research Institute has appointed Susana T. Valente as an assistant professor in the Department of Infectology.

Valente, who was an associate research scientist at Columbia University in New York before joining the Scripps Florida faculty.

"We are extremely pleased to have Susana join our department," said Charles Weissmann, the chair of the Department of Infectology. "She has an innovative approach to HIV and brings a fresh perspective to the search for novel ways to interrupt viral replication. She is a significant addition to the Scripps Florida faculty and we're happy to have her with us."

Valente's research focuses on identifying the molecular interactions that occur within a host cell that are critical for viral replication, and on understanding mammalian genes that have evolved to block that replication. This research could lead to therapeutic targets for combating a number of viruses, including those that might be used as bioterrorism agents.

"It's a great honor to become part of the Scripps Florida faculty," Valente said. "The collaborative atmosphere here is unique and I'm looking forward to developing some strong working relationships with many of my colleagues. The fact that Scripps Florida is dedicated to finding potential therapeutics for many diseases, including HIV, is another reason I'm excited about joining Scripps Florida."

Valente, who was born in the United States but raised in Lisbon, Portugal, attended the New University of Lisbon, where she received her degree in Applied Chemistry/Biotechnology. She also earned a masters degree (Maitrise) in biochemistry from the University of Paris and a master's degree in biotechnology from Montfort University in England and the Hogeschool West-Brabant, the Netherlands. Valente was awarded a Ph.D. in microbiology and virology from the University of Paris VII in 2002. She conducted postdoctoral studies in the laboratory of Stephen Goff, Ph.D., at Columbia University, a pioneer in the use of genetic screens to identify factors in retroviral resistance.

Viruses often use the host cell's machinery in unusual ways during their replication. In a recently published study in the journal Molecular Cell, Valente and colleagues focused on screening expression libraries for genes or gene fragments to identify host factors that might interfere with HIV–1 replication.

What the scientists discovered was that overexpression of a host protein called eIF3f (eukaryotic initiation factor 3 subunit f), which is normally involved in the translation of the cellular gene's message into a protein, has the power to block HIV replication. It does so by reducing the processing of the viral messenger RNA; mRNA, which is synthesized from the viral DNA during transcription, carries the DNA code into the cytoplasm of the cell, where it becomes a template for protein synthesis. Without mRNA, the virus cannot replicate.

"Those results suggest an important role of eIF3f in the maturation of viral messenger RNA," Valente said, "and indicate that eIF3f can interfere with the processing of HIV–1 mRNAs. That means that the viral mRNA is open to manipulation by this and other host factors. This offers a potential target that may ultimately lead to a new means to suppress viral replication. That's one of the main areas we intend to focus on at Scripps Florida."

Send comments to: mikaono[at]scripps.edu

Assistant Professor Susana Valente's research focuses on identifying the molecular interactions that occur within a host cell that are critical for viral replication, and on understanding the mammalian genes that have evolved to block that replication. (Photo by Eric Sauter.)