The results of their study are reported in the journal Nature Communications.
Cholesterol's role in heart disease has given it a bad reputation. But inside the thin membrane of a cell, the tight regulation of cholesterol at high levels (30 to 40 percent) suggests that it plays an important role in cellular processes, says Wonhwa Cho, professor of chemistry at the University of Illinois at Chicago and principal investigator on the study.
Cho and colleagues had previously found evidence that cholesterol was directly interacting with many proteins found in the interior of the cell. The interaction seemed necessary for the proper functioning of these proteins.
"This was quite a surprising finding," said Cho, because cholesterol resides within the membrane, sandwiched between its inner and outer face. Cell biologists had thought it could only interact with other biomolecules within the membrane.
In the new study, Cho and his colleagues showed how cholesterol interacts with a scaffolding protein, one of a class of proteins that plays an important role in cell signaling. The researchers showed that cholesterol binds to a region on the protein molecule where one of its signaling partners also binds -- and that disrupting cholesterol binding to the protein makes it unable to activate its partner.
The researchers describe in detail how the protein hooks onto and reaches inside the membrane to find and bind cholesterol.
Cho believes that this strategy for interacting with cholesterol may be used by many interior cellular proteins and offers an insight into what is known about the importance of cholesterol to well-functioning cells.
Much of the existing data on the cholesterol-related regulation of cellular processes had been difficult to interpret, he said.
"This is a major finding that will help people understand how cholesterol may regulate other cellular processes," Cho said.
Ren Sheng, graduate student in chemistry at UIC, was first author of the paper. Other authors are Yong Chen, Ewa Stec, Heather Melowic, Nichole Blatner and Moe Tun, all of the UIC chemistry department; Morten Kallberg and Hui Lu of the UIC bioengineering department; Heon Yung Gee, Yonjung Kim and Min Goo Lee of the Yonse University College of Medicine in Seoul; Takahiro Fujiwara and Akhiro Kusumi of Kyoto University in Japan; and Ji Hye Hong and Kwang Pyo Kim of Konkuk University in Seoul.
This study was supported by the Chicago Biomedical Consortium with the support of the Searle Funds at the Chicago Community Trust; National Institutes of Health grant GM68849; the World Class University program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology; and a grant from the National Project for Personalized Medicine, part of the Korea Health 21 R&D Project of the Korean Ministry of Health and Welfare.
UIC ranks among the nation's leading research universities and is Chicago's largest university with 27,000 students, 12,000 faculty and staff, 15 colleges and the state's major public medical center. A hallmark of the campus is the Great Cities Commitment, through which UIC faculty, students and staff engage with community, corporate, foundation and government partners in hundreds of programs to improve the quality of life in metropolitan areas around the world. For more information about UIC, please visit www.uic.edu.
NOTE: Please refer to the institution as the University of Illinois at Chicago on first reference and UIC on second reference. "University of Illinois" and "U. of I." are often assumed to refer to our sister campus in Urbana-Champaign.
Jeanne Galatzer-Levy | EurekAlert!
NIH scientists describe potential antibody treatment for multidrug-resistant K. pneumoniae
14.03.2018 | NIH/National Institute of Allergy and Infectious Diseases
Researchers identify key step in viral replication
13.03.2018 | University of Pittsburgh Schools of the Health Sciences
A new scenario seeking to explain how Mars' putative oceans came and went over the last 4 billion years implies that the oceans formed several hundred million...
For the first time, an interdisciplinary team from the University of Basel has succeeded in integrating artificial organelles into the cells of live zebrafish embryos. This innovative approach using artificial organelles as cellular implants offers new potential in treating a range of diseases, as the authors report in an article published in Nature Communications.
In the cells of higher organisms, organelles such as the nucleus or mitochondria perform a range of complex functions necessary for life. In the networks of...
Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...
On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...
The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...
19.03.2018 | Event News
16.03.2018 | Event News
13.03.2018 | Event News
20.03.2018 | Physics and Astronomy
20.03.2018 | Physics and Astronomy
20.03.2018 | Earth Sciences