Tuesday, Dec. 12, 2017
A Virginia Commonwealth University researcher has discovered a new conformation of a common protein group with links to cancer metastasis and neurodegenerative diseases.
Qinglian Liu, Ph.D., an associate professor in the Department of Physiology and Biophysics at VCU School of Medicine and research member at Massey Cancer Center, recently found a third variation in the structure of the protein type Hsp70, which is responsible for the growth and repair of other proteins. The findings were published in the journal Nature Communications on Oct. 31. The discovery could eventually lead to the development of small molecules that could either improve or curtail the function of Hsp70.
Hsp70, or 70 kilodalton heat shock protein, accounts for about 2 percent of the more than 100,000 protein types in the human body. The protein is a chaperone, which means it helps other proteins develop a shape. A protein’s shape helps determine its function. When proteins lose their shape from deterioration due to illnesses such as fevers, or from environmental stressors such as overexposure to sunlight, Hsp70 helps them reform.
“Everything we do, we can do because proteins function,” said. “Our cells are made of proteins and they all must fulfill their roles, similar to how everyone has a specific job in our society. She added that the role of Hsp70 is maintaining the health of proteins.
Finding the third shape of Hsp70 helps researchers uncover the biochemical function of this protein group.
“Understanding how the three shapes fit together reveals the process that Hsp70 goes through to fold proteins,” Liu said. “When you see all the shapes together, you can picture a video of them working in sequence to fold a protein.”
The first Hsp70 shape was discovered in 1996. Liu found the second shape in 2012 and more shapes await discovery after Liu’s most recent finding.
Hsp70’s ability to fold proteins and rebuild them once they lose their shape may hold part of the key to cures for cancer and certain neurological diseases, Liu said.
An overabundance of Hsp70 has been linked to cancer metastasis. Hsp70 can cause the proteins in cancer cells to continually fold, which exacerbates cell growth.
The opposite problem occurs in patients with neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease. In the case of Alzheimer’s, patients experience dangerous protein aggregates in the brain called amyloid plaques. Instead of being repaired after losing their shape, the proteins form these harmful buildups because there are not enough Hsp70s available to refold the proteins.
“We cannot survive without Hsp70, but it must be balanced,” Liu said. “We can’t have too much or too little. Once we understand more about Hsp70’s activity, we can design small molecules to modulate the activity of the protein, which could prevent or slow the growth of certain diseases.”
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About the VCU Massey Cancer Center
VCU Massey Cancer Center is among the top 4 percent of cancer centers in the country to be designated by the National Cancer Institute to lead and shape America’s cancer research efforts. Working with all kinds of cancers, Massey conducts every form of cancer research, including basic science, translational, clinical and population sciences research; provides state-of-the-art cancer treatments and cutting-edge clinical trials; serves as a vital resource for oncology education, teaching and training; and promotes cancer prevention. Since 1974, Massey has been an internationally recognized center of excellence. Massey provides award-winning cancer care at multiple sites throughout Virginia by leading cancer sub-specialists and offers one of the largest selections of cancer clinical trials as well as a statewide network that brings trials to communities across the commonwealth. Its 1,000-plus researchers, clinicians and staff members are dedicated to improving the quality of human life by discovering, developing, delivering and teaching effective means to prevent, detect, treat and ultimately cure cancer. Visit Massey online atmasseycancercenter.org masseycancercenter.org or call 877-4-MASSEY for more information.