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SDSU Marketing & Communications
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FOR IMMEDIATE RELEASE

SDSU Research Team Discovers New Protein
That May Regulate Heart Contractions
Characterization of 'SCaMPER' Protein Opens New Dimension in Heart Research
Results presented at American Heart Association meetings in Chicago

CHICAGO, Monday, November 18, 2002 - A research team at San Diego State University (SDSU) today announced they have found a new protein that plays a key role in regulating the strength of heart muscle contractions, a discovery that may open a new path in heart research toward developing future life-saving drugs.

Scientists already know that calcium causes cardiac muscle cells to contract, and that two previously identified proteins serve as "calcium channels" that regulate calcium flow into heart muscle cells. The SDSU-led team characterized the expression and function of a previously undescribed protein that serves as a calcium channel for the heart, which they termed the Sphingolipid Calcium Mediated Protein of the Endoplasmic Reticulum (SCaMPER). Just as importantly, the team also discovered that sphingolipids - potentially important signaling molecules - regulate SCaMPER's ability to control cardiac cell calcium. This raises the possibility that this protein could be an accessible target for new cardiac drugs.

Amy Cavalli, a student in the SDSU-University of California, San Diego joint Ph.D. program in biology, presented these findings this morning at the American Heart Association Scientific Sessions 2002, the world's largest convention for scientists and healthcare professionals devoted to the science of cardiovascular disease and stroke. Cavalli's presentation will also be one of about 25 included in the content of the "Best of Sessions 2002" satellite broadcast and webcast to cardiologists and hospitals across the United States on Friday, Nov. 21.

"This is a significant leap forward in understanding the cellular physiology of the heart," Cavalli said. "By characterizing SCaMPER and its relationship with sphingolipids, we've found a new control point that may help regulate the activity of a person's heart. It's the first step down a new avenue that scientists can explore in their quest to develop new therapeutics for cardiac patients."

Cavalli and the SDSU-based team spent four years researching and working in the labs at SDSU for this project under the support of a local biotech firm, Medlyte, Inc. They used various forms of analysis of human and rat cardiac tissue to first ascertain that SCaMPER exists in abundance on the surface of human heart cells. Through immunofluorescence and other techniques, fellow graduate student Nicole O'Brien determined SCaMPER molecules are concentrated in the transverse tubules of heart cells. They also found that sphingolipids signaled SCaMPER molecules to allow calcium levels to rise in the heart cells. Also, a sophisticated molecular biological tool was used to remove the protein from the heart cells, showing that the flow of contraction-causing calcium decreased 73 percent in SCaMPER's absence.

The team's work has been accepted for publication in an upcoming issue of American Journal of Physiology. Cavalli is the lead author.
SDSU Biology Professor Roger Sabbadini, the leader of the research team in SDSU's Heart Institute, said it may take some time for researchers to determine how to control this "on/off switch" and know its potential for clinical treatment, but it's a new approach that's worth pursuing.

"A steady, rhythmic heartbeat depends on a steady flow of calcium into the cardiomyocytes. If that flow is interrupted or becomes excessive from disease or trauma, cell death can result," he said. "By finding a way to alter SCaMPER's calcium-channeling properties, scientists potentially could find a new way to address this problem."

Other members of the SCaMPER research team include SDSU biology professors Christopher Glembotski and Steven Barlow, Dr. Philip T. Palade of the University of Texas Medical Branch's Department of Physiology and Biophysics, and Dr. Romeo Betto of the C.N.R. Institute of Neuroscience in the Department of Biomedical Sciences at the University of Padova, Italy.

San Diego State University is the oldest and largest higher education institution in the San Diego region. Since it was founded in 1897, the university has grown to offer bachelor's degrees in 79 areas, master's degrees in 62 areas and doctorates in 14 areas. Students participate in academic curriculum distinguished by direct contact with faculty and an increasing international emphasis that prepares them for a global future. For more information, visit www.sdsu.edu.

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Editor's Note: For a copy of today's presentation, contact Jason Foster at (619) 594-2585 or foster@mail.sdsu.edu.