January 4, 2010

Seven from JHU named AAAS fellows

Seven Johns Hopkins researchers from four of the university’s schools have been elected by their peers as fellows of the American Association for the Advancement of Science.

Pierre A. Coulombe and Marcelo Jacobs-Lorena of the Bloomberg School of Public Health, David Draper of the Krieger School of Arts and Sciences, David J. Linden and Cynthia Wolberger of the School of Medicine and Peter C. Searson and Denis Wirtz of the Whiting School of Engineering are among 531 new fellows around the world. Election as a fellow honors scientifically or socially distinguished efforts to advance science or its applications.

This year’s AAAS fellows were announced Dec. 18 in the “AAAS News & Notes” section of the journal Science. New fellows will be presented with an official certificate and a gold and blue (representing science and engineering, respectively) rosette pin on Saturday, Feb. 20, during the 2010 AAAS Annual Meeting in San Diego.

AAAS is an international nonprofit organization dedicated to advancing science around the world.

As part of the section on biological sciences, Pierre A. Coulombe, the E.V. McCollum Professor and Chair of the Department of Biochemistry and Molecular Biology at the Bloomberg School of Public Health, was elected for his studies on the role of differential keratin expression in the architecture, function and homeostasis of epithelial tissues.

Coulombe’s research focuses primarily on the keratin filament cytoskeleton in epithelial cells, with an emphasis on skin tissue. He is working to gain a better understanding of various key functions of keratin proteins, and keratin filaments, at a cellular and molecular level. Keratin gene mutations are causative for a large number of dominantly inherited diseases, including epidermolysis bullosa simplex. Following his discovery of mutations in select keratin genes of EBS sufferers, which he made as a postdoctoral fellow at the University of Chicago, Coulombe has continued to investigate this important problem and devise new ways to approach EBS-related conditions therapeutically.

Coulombe’s laboratory also discovered several previously unknown functions for keratin proteins, including a role in regulating protein synthesis and epithelial cell survival and growth during epithelial remodeling events. Such nonmechanical functions are contributing to cell and tissue homeostasis in circumstances of acute stress as well as chronic disease.

As part of the section on biological sciences, David Draper, a professor of chemistry in the Krieger School of Arts and Sciences and director of the university’s intercampus Program in Molecular Biophysics, was named for distinguished contributions to the field of biology, particularly for contributions to the understanding of the fundamental principles of RNA folding and protein-RNA binding.

RNA molecules were once thought to be primarily passive carriers of genetic information, but active roles for RNA molecules in the functioning of cells and viruses now are continually being uncovered. These additional roles require some RNAs to adopt intricate structures and recognize other cellular components. Draper has used a variety of physical, biochemical and genetic techniques to explore the various strategies RNAs use to fold into their functional structures and to respond to cellular factors. Some of the RNAs that are being studied include structures essential for retrovirus infectivity, a target for an antibiotic that inhibits protein synthesis, and “riboswitches” that modulate gene expression in response to changing cellular conditions.

As part of the section on medical sciences, Marcelo Jacobs-Lorena, a professor in the Bloomberg School of Public Health’s Malaria Research Institute and W. Harry Feinstone Department of Molecular Microbiology and Immunology, was elected for distinguished contributions to the field of insect vector biology, particularly malaria parasite/mosquito interactions and genetic modification of mosquito vector competence. His research focuses on the interactions between Plasmodium, the parasite that causes malaria, and mosquitoes that transmit the disease to humans.

Malaria kills more than 1 million people every year. Jacobs-Lorena is pioneering a novel approach to make mosquitoes incapable of transmitting the malaria parasite. His studies have examined ways to genetically modify the mosquito itself and to change the bacteria that inhabit the mosquito gut. He also has identified the mechanisms used by the malaria parasite to invade and traverse mosquito midgut and salivary glands, a process that is essential for malaria transmission. Jacobs-Lorena’s laboratory is also exploring the mechanism by which the malaria parasite recognizes and invades the mammalian liver.

As part of the section on neuroscience, David J. Linden, a professor of neuroscience in the School of Medicine, was elected for distinguished contributions to the field of cellular neurophysiology; in particular, his fundamental advances to our understanding of the cellular and molecular substrates of memory.

Linden researches many aspects of memory, including everything from when memories are first collected to how they affect our ability to interact with the world. His work focuses on the cerebellum, the part of the brain that receives input from our senses and influences motor functions such as walking. Nestled inside the cerebellum are the Purkinje neurons, cells that act as a “sketch pad” for the brain, a space for temporary information storage of one to 100 seconds. These sketches of how our surroundings look, sound or feel help influence our interaction with the world, everything from moving around obstacles to using fine motor skills such as writing.

Linden researches how Purkinje neurons and other cells in the cerebellum function, utilizing rodent models to learn how the cells store information and how they communicate with other parts of the brain. By examining a single cell’s reaction to electric stimulus or observing which molecular messages cells send to other cells, Linden has made significant advances in understanding how memory works.

As part of the section on engineering, Peter C. Searson, the Joseph R. and Lynn C. Reynolds Professor of Materials Science and Engineering in the Whiting School, was elected for distinguished contributions to the field of surface chemistry and nanoscience. His research interests include surface and molecular engineering and semiconductor quantum dots.

Searson directs the interdivisional Institute for NanoBioTechnology, which was launched in May 2006 to bring together Johns Hopkins researchers in the fields of medicine, engineering, the sciences, and public health to create knowledge and develop technologies to revolutionize health care and medicine. INBT has more than 190 affiliated faculty members.

Searson has secondary appointments in the Krieger School’s Department of Physics and Astronomy and the School of Medicine’s Department of Oncology.

As part of the section on engineering, Denis Wirtz, the Theophilus H. Smoot Professor of Chemical and Biomolecular Engineering in the Whiting School, was elected for contributions to cell micromechanics and cell adhesion and for the development and application of particle-tracking methods to probe the micromechanical properties of living cells in normal conditions and disease states.

Wirtz studies the biophysical properties of healthy and diseased cells, including interactions between adjacent cells and the role of cellular architecture on nuclear shape and gene expression. Wirtz directs the newly formed Johns Hopkins Engineering in Oncology Center, a Physical Sciences in Oncology Program center of the National Cancer Institute. EOC brings together Johns Hopkins experts in cancer biology, molecular and cellular biophysics, applied mathematics, materials science and physics to study and model cellular mobility and the assorted biophysical forces involved in the spread of cancer.

Wirtz also serves as co-director of the Institute for NanoBioTechnology and has a joint appointment in the School of Medicine’s Department of Oncology.

As part of the section on biological sciences, Cynthia Wolberger, an investigator with the Howard Hughes Medical Institute and a professor in the School of Medicine’s Department of Biophysics and Biophysical Chemistry, was elected for distinguished contributions to the field of structural biology, particularly for studies of transcriptional regulatory proteins.

Wolberger studies how proteins do their job in the body. AAAS has specifically noted her excellent work characterizing transcription regulator proteins, those molecules that control gene expression. Although scientists know which molecular players are involved in certain processes, how they work together is a mystery. Wolberger’s research starts at the beginning of the story: discovering how a protein is structured. To learn what a protein looks like, her lab uses X-ray crystallography, a process in which a protein is exposed to focused X-rays. By mapping the patterns the X-rays make, Wolberger can create a three-dimensional model of the complex twists and turns of a protein to help her understand how a protein will bind to DNA, thus turning gene production on or off. Wolberger’s research has led to a better understanding of the molecular mechanisms behind medical problems such as cancer, aging and diabetes.

Contributing this story were Lisa De Nike, Homewood; Tim Parsons, Bloomberg School of Public Health; and Mary Spiro, Whiting School of Engineering/Institute for NanoBioTechnology.