The National Institute of General Medical Sciences (NIGMS),
one of the National Institutes of Health, supports all research
featured in this digest. Although only the lead scientists
are named, coworkers and other collaborators also contributed
to the findings. To read additional news items, visit NIGMS
Cool Image: Mapping Brain Differences
This image of the human brain uses colors and shapes
to show neurological differences between two people. The
blurred front portion of the brain, associated with complex
thought, varies most between the individuals. The blue ovals
mark areas of basic function that vary relatively little.
Visualizations like this one are part of a project to map
complex and dynamic information about the human brain, including
genes, enzymes, disease states, and anatomy. The brain maps
represent collaborations between neuroscientists and experts
in math, statistics, computer science, bioinformatics, imaging,
and nanotechnology. Courtesy of Arthur Toga, a neuroscientist
at the University of California, Los Angeles, and head of
the Center for Computational Biology, which is supported
by the bioinformatics and computational biology component
of the NIH Roadmap for Medical Research.
CCB home page (no longer available)
Roadmap home page
Researchers Find Fountain of Youth in Yeast
Ever heard that drastically cutting calories can help you live longer? While
this claim has not yet been proven in humans, basic researchers
working with simple organisms have observed a link between
eating very little and living longer. Some have shown that
growing yeast cells in a low-calorie broth can keep these
cells youthful by blocking the deadly build-up of toxic amounts
of extra DNA. Geneticist David Sinclair of Harvard Medical
School and microbiologist Su-Ju Lin of the University of California,
Davis, have now identified a trio of genes in a family of
proteins called sirtuins that account for the life-extending
effects of caloric restriction in yeast. The study also suggests
that sirtuins may contribute to health and lifespan in other
organisms, including humans.
Hope for Children with Fatal Aging Syndrome
Caption: Cells containing the mutant form of lamin
A that causes the aging syndrome. The aberrant, irregularly
shaped nuclei are in green. Courtesy of Michaelis.
Thanks to an earlier discovery and some scientific detective
work, a compound being tested for treating cancer may help
children with Hutchinson-Gilford progeria syndrome—a
rare, fatal, premature aging condition. Susan Michaelis, a
cell biologist at Johns Hopkins University, had been studying
enzymes that modify the lamin A protein when geneticists pinpointed
a mutation in the lamin A gene as the source of the syndrome.
Michaelis followed her hunch and now has shown that the genetic
flaw shackles the lamin A protein to a fatty chemical group,
causing the cellular abnormalities seen in children with the
condition. The compound being tested frees lamin A from its
fatty appendage and may prove beneficial in children with
abstract (from the October 4, 2005 issue of PNAS)
Approach Offers Proof of Principle for Studying
Caption: Repeated structure of a voltage-dependent
potassium ion channel. Courtesy of Science.
With the help of a special group of proteins embedded in
the outer membrane of cells, our nerves send signals, our
muscles flex, and our hormones get secreted. Yet these medically
important molecules remain relatively mysterious, partly
because they aren’t abundant in their purest form.
A team of scientists led by Roderick MacKinnon, a structural
biologist and Nobel laureate at Rockefeller University,
has now successfully produced enough of a mammalian membrane
protein in a simple organism and determined its structure.
The protein is called a voltage-dependent potassium ion
channel, and it helps transmit electrical signals into and
out of heart and nerve cells. The combination of techniques
the researchers used to express, purify, crystallize, and
visualize the protein could open the door to studying other
membrane proteins involved in health and disease.
abstracts (from the August 5, 2005 issues of Science)
Beta-Blockers Could Be Risky for Some Heart
Many heart patients take medications called beta-blockers,
which lower blood pressure and slow heart rate, to reduce
the risk of heart attacks and prolong survival. But beta-blockers
also increase deaths in heart patients with certain genetic
profiles, according to new research by pharmacologist Howard
McLeod of the Washington University in St. Louis School
of Medicine. Working as part of the NIH Pharmacogenetics
Research Network, McLeod and his collaborators focused on
two genes, ADRB1 and ADRB2, that interact with beta-blockers.
They looked at the composition of these genes in more than
700 patients hospitalized for heart attacks or unstable
angina, many of whom were sent home on beta-blockers. Patients
who took beta-blockers and who had certain common versions
of ADRB2 were about three times more likely to die within
three years as those with other versions of the gene or
those not taking beta-blockers. This discovery will help
doctors predict whether the benefits of beta-blockers outweigh
the risks for some patients.
abstract (from the September 28, 2005 issue of JAMA)
NIGMS-Supported Chemists Win Nobel
Robert Grubbs of the California Institute of Technology
and Richard Schrock of the Massachusetts Institute of
Technology won the 2005 Nobel Prize in chemistry. The
two scientists, who received the prize along with French
chemist Yves Chauvin, worked independently to develop
molecules called catalysts that promote powerful bond-forming
reactions. The catalysts have a wealth of applications
in basic research, drug development, and materials preparation.
NIGMS has provided nearly $12 million in funding to the
U.S. chemists over two decades. Since 1962, the Institute
has supported the work of 59 Nobel laureates.