Jorge E. Galan talks with
ScienceWatch.com and answers a few questions about
this month's Fast Moving Front in the field of
Article: Protein delivery into eukaryotic cells by
type III secretion machines
Journal: NATURE, 444 (7119): 567-573 NOV 30 2006
Addresses: Yale Univ, Sch Med, Boyer Ctr Mol Med, Sect
Microbial Pathogenesis, New Haven, CT 06536 USA.
Yale Univ, Sch Med, Boyer Ctr Mol Med, Sect Microbial
Pathogenesis, New Haven, CT 06536 USA.
Umea Univ, Dept Mol Biol, SE-90187 Umea, Sweden.
Why do you think your paper is highly
One of the most exciting discoveries in the field of bacterial pathogenesis
during the past few years has been the finding that many pathogenic or
symbiotic bacteria use complex, supramolecular machines to transfer
bacterial proteins into eukaryotic cells to modulate their function. There
are at least three different types of these machines, which are known as
type III, type IV, and type VI protein secretion machines.
Type III secretion systems, the subject of this article, were the first to
be discovered and therefore are probably better understood. Since these
machines are essential for the pathogenesis or symbiosis of many bacteria,
this is a topic of great interest to many scientists.
Does it describe a new discovery, methodology, or
synthesis of knowledge?
Type III secretion
This article attempted to synthesize the knowledge in the field from the
standpoint of the article's authors, myself and my friend and colleague
Hans Wolf-Watz of Umeå University. We have been working on these
systems since their discovery and consequently have had an opportunity to
see the field evolve into what it is today, an extremely exciting area of
Would you summarize the significance of your paper
in layman's terms?
This paper describes a remarkable protein-delivery device that many
pathogenic or symbiotic bacteria utilize to "inject" bacterial proteins
into the cells of animals, plants, and even insects. Pathogens need this
machine in order to cause disease, therefore its understanding could lead
to novel therapeutic avenues.
How did you become involved in this research and
were any particular problems encountered along the way?
Both Hans Wolf-Watz and I have been working in this field essentially since
its very beginning. Of course, as in any research endeavor, we have
encountered many obstacles along the way, which has made it even more
challenging and exciting.
Where do you see your research leading in the
We are just beginning to gain a mechanistic understanding of these protein
delivery machines. We do know all the "spare parts" of these systems and
the challenge now is to understand how they function together to do what
they do so well: inject bacterial proteins into eukaryotic host cells.
Do you foresee any social or political implications
for your research?
Since these machines are central for the pathogenicity of numerous and
quite important bacterial pathogens, the understanding of their
functionality offers a unique opportunity for the development of novel
therapeutic strategies to combat key infectious diseases, among which are
typhoid fever, food poisoning, plague, and cholera.
Jorge E. Galán, Ph.D.
Lucille P Markey Professor of Microbial Pathogenesis and Cell Biology
Chair, Microbial Pathogenesis
Section of Microbial Pathogenesis
Yale University School of Medicine
New Haven, CT, USA