Monday, January 31, 2011

New method takes snapshots of proteins as they fold

Scientists have invented a way to ‘watch’ proteins fold — in less than thousandths of a second — into the elaborate twisted shapes that determine their function.



By Diana Lutz


An unfolded protein is a string made up of amino acids. When the protein folds it forms structures like the alpha helix (the corkscrew) and the beta sheet (the flat ribbon) in the image to the right. These secondary structures then double back on themselves to form the final structure.

People have only 20,000 to 30,000 genes (the number is hotly contested), but they use those genes to make more than 2 million proteins. It’s the protein molecules that do most of the work in the human cell. After all, the word protein comes from the Greek prota, meaning “of primary importance.”

Proteins are created as chains of amino acids, and these chains of usually fold spontaneously into what is called their “native form” in milliseconds or a few seconds.

A protein’s function depends sensitively on its shape. For example, enzymes and the molecules they alter are often described as fitting together like a lock and key. By the same token, misfolded proteins are behind some of the most dreaded neurodegenerative diseases, such as Alzheimer’s, Parkinson’s and mad cow disease.

Scientists can’t match the speed with which proteins fold. Predicting how chains of amino acids will fold from scratch requires either powerful supercomputers or cloud sourcing (harnessing the pattern recognition power of thousands of people by means of games such as Folding@home).

Either way, prediction is time-consuming and often inaccurate, so much so that the protein-structure bottleneck is slowing the exploitation of DNA sequence data in medicine and biotechnology.

A clever way of watching proteins fold and unfold may finally provide the kind of detail needed to improve protein structure predictions.


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Thursday, January 27, 2011

Biologists’ favorite worm gets viruses

Marie-Anne Felix, the Monod Institute

Scientists have discovered that C. elegans, a microscopic worm biologists have used in the lab to identify important biological phenomena, suffers from natural viral infections. This may mean that C. elegans can help scientists learn more about how hosts and viruses interact.

A workhorse of modern biology is sick, and scientists couldn’t be happier.

Researchers at Washington University School of Medicine in St. Louis, the Jacques Monod Institute in France and Cambridge University have found that the nematode C. elegans, a millimeter-long worm used extensively for decades to study many aspects of biology, gets naturally occurring viral infections.

The discovery means C. elegans is likely to help scientists study the way viruses and their hosts interact.

“We can easily disable any of C. elegans’ genes, confront the worm with a virus and watch to see if this makes the infection worse, better or has no effect,” says David Wang, PhD. “If it changes the worm’s response to infection, we will look to see if similar genes are present in humans and other mammals.”

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Wednesday, January 26, 2011

Cancer information tool for journalists wins Health 2.0 developer challenge

Health 2.0 and the National Cancer Institute (NCI) recently named Ozioma, an online cancer information tool from the Health Communication Research Laboratory (HCRL) at Washington University in St. Louis, one of two winners of a national contest.


The Ozioma News Service was chosen a winner of the Enabling Community Use of Data for Cancer Prevention and Control Challenge, a part of the 2010 Health 2.0 Developer Challenge.

The Ozioma tool helps reporters and media relations professionals create localized cancer stories for specific populations in specific communities.

View a brief video about Ozioma.

“For those who write about and report on health, providing a central location to access community-level health data can increase the likelihood that they’ll include these data in their stories,” says Charlene A. Caburnay, PhD, research assistant professor at the Brown School at Washington University.

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Tuesday, January 25, 2011

Three DBBS faculty receive Children’s Discovery Institute grants

Three Washington University School of Medicine researchers have received grants from the Children’s Discovery Institute to advance their work into childhood diseases.


The Children’s Discovery Institute is a partnership between Washington University School of Medicine and St. Louis Children’s Hospital to accelerate better treatments, cures and preventions for childhood diseases.

Todd Druley, MD, PhD, received a CDI Faculty Scholar Award for his research into the genetic basis of a fast-growing cancer of the white blood cells called high-risk acute lymphoblastic leukemia (ALL) that primarily affects teenagers .


Druley
Through his work in the Center for Genome Sciences and Systems Biology, Druley developed a method in 2009 for surveying many genes in a pool of DNA from more than 1,000 people using next-generation sequencing. This work was published in Nature Methods. Now, he is applying that method to children with high-risk ALL looking for genetic mutations that may be behind the cancer.

“It is unlikely that there will be one or two mutations in DNA that cause children to get ALL,” he says. “We predict that there will be a lot of different mutations in a lot of different genes that have little consequence individually, but can have a synergistic effect that results in a serious problem.”

By targeting genes already identified from genome-wide arrays done on children with high-risk ALL, Druley will study several hundred genes in about 450 DNA samples from children enrolled in nationwide high-risk ALL trials.

High-risk leukemia affects about one in 100,000 children, but unlike standard-risk ALL, is curable only about 65 percent to 75 percent of the time. Unfortunately, physicians haven’t made much progress in treating the disease with chemotherapy, so many patients require bone marrow transplants, which can be difficult physically and emotionally for these teens.

“We hope to understand how high-risk ALL is coming about in the first place so we can design more effective treatments,” says Druley, an assistant professor of pediatrics and of genetics at the School of Medicine who also treats patients at St. Louis Children’s Hospital.

Druley began the work as a postdoctoral researcher in the Washington University lab of Robi Mitra, PhD, assistant professor of genetics, in the Center for Genome Sciences and will continue the work with the CDI grant through at least 2013.

Kelle Moley, MD, has received a grant from the Children’s Discovery Institute to facilitate research among Washington University researchers on pregnancy, maternal-fetal interaction and pediatric diseases.

The project, the Women and Infants Health Specimen Consortium (WIHSC), will collect tissue samples such as cord blood and amniotic fluid from mothers and their infants and link them with a clinical database. Participants will be recruited from the Washington University Reproductive Endocrinology and Infertility Clinic and the Center for Advanced Medicine. This project is unique, Moley says, because individual mother-infant pairs will be followed before, during and after pregnancy.

“Washington University has many researchers who study women and infants’ health, disease, fertility, pregnancy and the neonatal period,” says Moley, the James P. Crane Professor of Obstetrics and Gynecology. “The pooling of resources could lead to increased access to a collection of specimens from pregnant and nonpregnant women, which would undoubtedly help facilitate research.”

Samples collected through the WIHSC will be available to School of Medicine investigators to study areas such as fetal and developmental origins of childhood diseases; the interaction and communication between the fetus and mother in utero; and to possibly identify biomarkers that predict poor pregnancy and poor infant outcomes, such as miscarriage and pre-term births.

“This consortium has the potential to become a vital source of tissue and patient data, from both mother and child, needed to accelerate new pathways to discovery in childhood disease,” Moley says.

Ann Gronowski, PhD, associate professor of pathology and immunology, and Marwan Shinawi, MD, assistant professor of pediatrics, are co-principal investigators of the WIHSC.


Sheila Stewart, PhD, received a grant to expand a library of molecular tools that can selectively turn off every gene in the mouse genome.

Called an shRNA library, it is a resource that allows researchers to “knock down” or deplete a gene of interest. By turning off a gene and observing the consequences, scientists can gain insight into that gene’s role in the biological process. This library will provide the Washington University research community with the tools to study human disease in a mouse model at a much lower cost.

Deleting or inserting a gene and observing the consequences is not a new research technique. While this technology has changed the way researchers ask important questions, standard methods can be cumbersome, time-consuming and expensive. An shRNA library, however, takes advantage of RNA interference (RNAi), a more recently discovered mechanism for turning off the expression of genes. Normally, a gene codes a strand of messenger RNA, which then codes for a protein. Traditionally, scientists would remove the gene, eliminating its messenger RNA and the resulting protein. With RNA interference, instead of going through the difficult process of removing the gene, scientists use shRNA strands that interfere with the messenger RNA and prevent it from creating the protein.

“Because of the way we created this system, we can introduce our RNAi construct to any kind of cell,” Stewart says. “This approach uses the RNAi machinery that is naturally in cells to take out the gene we tell it to. Once there is none of that gene’s protein left, we can look at the function of the protein in the context of the disease we’re studying. Did removing the protein make the disease better or worse or change anything?”

Elaine Mardis, PhD, co-director of The Genome Center and director of technology development, and David Piwnica-Worms, MD, PhD, professor of developmental biology and of radiology, are collaborating with Stewart on the CDI grant.

Researchers at The Genome Center, led by Mardis, also associate professor of genetics and of molecular microbiology, are making DNA that is usable for researchers studying disease, and Stewart's group is turning it into an infectious virus that can be used to screen for genes that impact a wide variety of human diseases.

It’s very expensive to make usable DNA and introduce it into a cell, Stewart says, but by turning it into an infectious virus, researchers can get it into almost all cells. These libraries represent an opportunity for WUSTL researchers to study any type of cell, especially those most relevant to the disease a researcher is interested in, Stewart says.

Stewart’s lab is also training other researchers on how to use the library. Earlier, Stewart received a CDI grant to expand the human genome library.

Monday, January 24, 2011

Deep genomics: Scientists probe the epigenome

The Washington University in St. Louis team participating in the modENCODE project, a massive ongoing effort to map all the elements in living cells that affect whether genes are expressed or silenced, discuss a fruit fly strain with an enzyme that affects gene expression. Team members are (from left): Sarah C.R. Elgin, PhD, the Viktor Hamburger Distinguished Professor in Arts & Sciences who led the team; Sarah Gadel, lab technician; Nicole C. Riddle, PhD, research assistant professor of biology in Arts & Sciences; and Tingting Gu, PhD, a postdoctoral research associate in biology. Missing is Sarah Marchetti, a technician. A major paper that includes their part of the modENCODE project has just been published in Nature.


In 2003, the year a complete draft of the human genome was released, the U.S. National Human Genome Research Institute launched the ENCODE project (ENCyclopedia of DNA Elements), to develop an encyclopedia of the epigenome, that is, of all of the many factors that can change the expression of the genes without changing the genes.


Four years later, the National Institutes of Health funded modENCODE (the Model Organism ENCylopedia of DNA Elements) to work out the epigenomes of two model organisms: the fruit fly Drosophila melanogaster, lurker among rotten bananas, and the round worm, Caenorhabditis elegans, slitherer between crumbs of soil.

This was big science with a vengeance. The work had been divided among 21 teams, themselves each made up of multiple labs, all toiling away at universities and companies across the country. And that’s not counting the research groups tasked with coming up with new ways of handling the floods of data pouring out of the labs.

What was going on?

Sarah C.R. Elgin, PhD, the Viktor Hamburger Distinguished Professor in Arts & Sciences, who led the Washington University in St. Louis lab that is part of one of the modENCODE teams, offers an explanation.

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Friday, January 21, 2011

Interviews Have Begun!

Today marked the start of the 2011 Interview Season. After receiving well over 1000 applications, DBBS will be interviewing hundreds of students for positions in our 12 programs.
For a list of interview weekends, you can go HERE
For information on the Division, click HERE
Dr. John Russell speaking to applicants.

Wednesday, January 19, 2011

Kidney gene implicated in increased heart failure risk

Scientists have identified the first DNA sequence variant common in the population that is not only associated with an increased risk of heart failure, but appears to play a role in causing it.

The variant, a change in a single letter of the DNA sequence, impairs channels that control kidney function.

“It’s not a heart gene,” says Gerald W. Dorn II, MD, the Philip and Sima K. Needleman Professor of Medicine at Washington University School of Medicine in St. Louis and a lead investigator on the study. “It’s a kidney gene. This protein is not even expressed in the heart. Nobody has previously considered that kidney-specific gene defects might predispose you to heart failure.”

Heart failure is diagnosed when the heart can no longer provide sufficient blood to the body. It can have a number of causes, including high blood pressure, cancer therapy, viral infections of the heart or heart attack.

“It’s a syndrome,” Dorn says. “You’ve had sufficient damage to your heart that it doesn’t work very well. You collect fluid in your lungs, you swell up, and you have trouble breathing.”

The unexpected results highlight the advantage of performing genome-wide studies to find DNA sequence variants associated with disease.

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