Dr. Nancy Nader, Research Associate in physiology & biophysics at WCM-Q, during a research.
DOHA: WCM-Q researchers have discovered that a protein known to play a key role in cholesterol uptake and brain development is also crucial to the process of reproduction.
Discovered in 1922, the Very Low-Density Lipoprotein Receptor (VLDLR) protein, has long been known to facilitate the migration of neurons in the developing brain and to play a role in cholesterol uptake. Up until now its role as a chaperone protein for membrane receptor trafficking was unknown.
Lead author of the research, Dr. Nancy Nader, Research Associate in Physiology & Biophysics at WCM-Q, explained: “The role of the hormone progesterone in turning immature oocytes (ovarian cells) into mature eggs, in a process known as ‘oocyte maturation’ that prepares the cell for fertilisation, is well known. Progesterone mediates its action by binding to a specific protein, known as the membrane progesterone receptor (mPR), located at the plasma membrane, which is the outer membrane of the cell.”
“However, the early steps that trigger oocyte maturation at cellular level are still unknown. By studying frog oocytes in the laboratory we were able to discover that the VLDLR protein acts as a ‘delivery truck’ or chaperone that helps deliver mPR to the plasma membrane and hence mediates its action after progesterone treatment.” The research team also made use of advanced biochemistry and microscopy techniques to confirm the findings. Interestingly, by knocking down VLDLR protein levels within oocytes, they observed an inhibition of oocyte maturation and significantly much less mPR at the plasma membrane.
The study was supported by the Qatar National Research Fund (QNRF) grant NPRP 7-709-3-195 and the Biomedical Research Program (BMRP) of Weill Cornell Medicine-Qatar, a programme supported by Qatar Foundation.
