This is the twice-per-month electronic newsletter for basic, preclinical and translational research news related to the Johns Hopkins School of Medicine. Please forward freely. Direct comments or questions to Joanna Downer, PhD, in the Office of Corporate Communications (4-5105, jdowner1@jhmi.edu).
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IN THIS ISSUE:
** Young Investigators' Day is Thursday, April 14 **
RESEARCH HIGHLIGHTS:
+ Proteins Found that Help Brain Cells Swap Ion Channels
+ Yeast Sterol Pathway is Oxygen Sensor
+ Urine Helps Infectious Yeast Stick
NEWS BRIEFS:
Young Investigators' Day Celebration April 14
Epigenetics Symposium To Be Held May 31
AWARDS AND HONORS:
Persaud Named Glaser Foundation Scientist
IN THE NEWS:
Nicholas Katsanis in The Boston Globe
Jennifer Elisseeff in the Grand Blanc (Michigan) News
Akhilesh Pandey in The Telegraph
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Do you have an interesting research finding about one month from publication or presentation? Send manuscripts to Joanna Downer at jdowner1@jhmi.edu or fax to 410-614-8951. Information about awards and honors received by laboratory personnel and others is welcomed also.
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RESEARCH HIGHLIGHTS:
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3/23/05
Proteins Found that Help Brain Cells Swap Ion Channels
Johns Hopkins researchers have identified the proteins that allow specific brain cells to swap one set of ion channels for another, a rare ability that tweaks what can come into the cell. The findings are described in the March 24 issue of Neuron.
Although the cells' channel-changing ability has been recognized for a few years, the key players controlling it hadn't been identified. Now, by studying genetically engineered mice, the Hopkins team has identified two proteins, called PICK1 and NSF for short, that help replace channels that let charged calcium ions in with another kind of channel that keeps calcium out.
Swapping their channels lets these cells, called stellate cells, fine-tune their messages and adjust connections within the cerebellum, the brain region that controls fine motor skills. If muscle-controlling nerve cells can do the same thing, forcing the swap might help protect them from a calcium overdose that can kill them in Lou Gehrig's disease, notes Richard Huganir, PhD, professor of neuroscience and a Howard Hughes Medical Institute investigator in Johns Hopkins' Institute for Basic Biomedical Sciences.
The swap, stimulated by an electric shock, replaces channels made of AMPA receptors built from subunits called GluR3 and GluR4 with ones made of subunits GluR2 and GluR3. After the swap, sodium can still get in, but calcium is kept out.
http://www.hopkinsmedicine.org/Press_releases/2005/03_23_05.html
Neuron 24 March 2005;45(6):903-915.
http://dx.doi.org/10.1016/j.neuron.2005.02.026
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3/24/05
Yeast Sterol Pathway is Oxygen Sensor
In experiments with yeast, Johns Hopkins researchers have discovered that a gene that helps the organism make a relative of cholesterol also helps it survive when oxygen is scarce. The finding, described in the March 25 issue of Cell, offers a new strategy for killing infectious yeast, but it also suggests that cells' efforts to make cholesterol and detect oxygen levels might be connected in people, too.
"We were simply trying to establish that S. pombe could be a model for studying cholesterol-related activities in human cells," says the study's leader, Peter Espenshade, PhD, assistant professor of cell biology in Johns Hopkins' Institute for Basic Biomedical Sciences. "We certainly didn't expect to find a completely new role for this gene."
In people, the gene in question, known as SREBP, controls other genes whose products help make or import cholesterol. By reviewing databases of the entire genetic sequences of various yeast, Espenshade found genes similar to SREBP and its binding partner SCAP in S. pombe, but not in S. cerevisiae.
Graduate student Adam Hughes then examined the role of the yeast genes, called sre1 and scp1, and showed that they do, in fact, duplicate the human process. But unexpectedly, he also discovered that yeast missing sre1 couldn't survive in low-oxygen conditions.
http://www.hopkinsmedicine.org/Press_releases/2005/03_24_05.html
Cell 25 March 2005;120(6):831-842.
http://dx.doi.org/10.1016/j.cell.2005.01.012
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3/29/05
Urine Helps Infectious Yeast Stick
Researchers from Johns Hopkins and the University of Maryland have discovered that urine actually helps a particular yeast stick to cells along the urinary tract. The finding might offer a new way to prevent or treat certain yeast and fungal infections, and the researchers' work also provides an unexpected new role for some proteins already known to help hungry yeast live longer.
Writing in the March 17 online express section of Science, the researchers report that the yeast Candida glabrata use a family of proteins called sirtuins to block access to genes that would otherwise help the yeast stick. The sirtuins, which also help regulate the organism's lifespan, require niacin, or vitamin B3, to work.
However, when the yeast are grown in urine, which has only tiny amounts of niacin, the sirtuins don't work, the genes are exposed, and the yeast can make the proteins that help it stick to cells in the urinary tract, the researchers discovered.
"It turns out that there's enough niacin in blood to keep the yeast's adhesion-promoting genes turned off," says Brendan Cormack, PhD, professor of molecular biology and genetics in Johns Hopkins' Institute for Basic Biomedical Sciences. "But in urine and perhaps other host environments, there is such a limited amount of niacin that these genes are turned on, allowing the organism to stick to host cells."
The researchers' latest work demonstrates that environmental influences -- not just the engineered loss of a gene -- can dictate whether the yeast can use their adhesion-promoting genes, previously dubbed EPA genes by Cormack's team.
http://www.hopkinsmedicine.org/Press_releases/2005/03_29_05.html
Science Express (Published online 17 March 2005)
http://dx.doi.org/10.1126/science.1108640
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NEWS BRIEFS:
Young Investigators' Day Is April 14 -- The 28th annual Young Investigators' Day celebration at the School of Medicine will be held April 14, starting at 4 p.m. in Mountcastle Auditorium in the Preclinical Teaching Building. Student awardees Jeffrey Han, Christopher Brett, David Maag, Jr., and Kara Lassen and postdoctoral awardees Chenghua Gu, PhD, and Sunil Karhadkar, MD, will give lectures on their work. All award recipients will host posters on their research at a reception to begin at 5:30 p.m. Young Investigators' Day was established in 1978 to recognize trainees at the School of Medicine and to provide them with a forum for presentation of their work. For a detailed schedule and list of award recipients, visit:
http://www.hopkinsmedicine.org/Press_releases/2005/YIDschedule
Epigenetics Symposium To Be Held May 31 -- An all-day symposium, "Completing the Book of Life: Epigenetics in Science and Medicine," is scheduled to begin at 8:15 a.m., Tuesday, May 31, in Wood Basic Science Auditorium. Invited experts will discuss the latest findings and applications of epigenetics in development, health and disease. Speakers will be symposium organizer Andrew Feinberg, Cynthia Wolberger, Stephen Baylin and Victor Corces of Johns Hopkins; Rolf Ohlsson of Uppsala University, Sweden; Vicki Chandler of the University of Arizona; Steven Henikoff of Fred Hutchinson Cancer Research Center and the Howard Hughes Medical Institute; Gary Felsenfeld of the National Institutes of Health; Shiv Grewal and Carl Wu of the National Cancer Institute; Ali Shilatifard of the Saint Louis University Cancer Center and Saint Louis University School of Medicine; and Shelley Berger of the University of Pennsylvania School of Medicine. Additional details will be available soon.
AWARDS AND HONORS:
Persaud Named Glaser Foundation Scientist -- Deborah Persaud, MD, a pediatric infectious disease specialist at the Johns Hopkins Children's Center, is the 2005 recipient of the Elizabeth Glaser Pediatric AIDS Foundation's 2005 Scientist Award. The award includes a $700,000 research grant. Calling the award an "incredible honor," Persaud added that the funds will advance her work on extent, effect and persistence of HIV drug resistance in children exposed as infants to antiretroviral drugs.
http://www.hopkinsmedicine.org/Press_releases/2005/03_16_05.html
IN THE NEWS:
Nicholas Katsanis on inheritance of complex traits like eye color in The Boston Globe: "How is Eye Color Inherited?" by Judy Foreman, The Boston Globe, April 12, 2005.
http://www.jhu.edu/clips/2005_04/12/howis.html (must be at a Johns Hopkins computer for access)
Jennifer Elisseeff on her cell engineering research in the Grand Blanc (Michigan) News: "Engineering Success," the Grand Blanc News, April 3, 2005.
http://www.jhu.edu/clips/2005_04/07/success.html (must be at a Johns Hopkins computer for access)
Akhilesh Pandey on annotation of the X chromosome in The Telegraph (Calcutta): "Indians Track Rogue Genes," by B. K. Srikanth, The Telegraph, April 2, 2005.
http://www.telegraphindia.com/1050403/asp/frontpage/story_4568419.asp#
http://www.jhu.edu/clips/2005_04/04/genes.html (must be at a Johns Hopkins computer for access through this link)
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Find "Change" and "Basics" online from a Hopkins computer:
http://www.insidehopkinsmedicine.org/change
Visit the "Research WebNotes" newsletter online:
http://www.hopkinsmedicine.org/webnotes/
For more news from Hopkins, see:
http://www.hopkinsmedicine.org/Press_releases/index.html
Upcoming lectures and seminars:
http://www.hopkinsmedicine.org/faculty_staff/scicalendar.html
Find more news stories about Hopkins at:
http://www.insidehopkinsmedicine.org and click on "News Clips"
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--JHMI--
