Locating the FSH Receptor using Fluorescent Imaging and Atomic Force Microscopy

The Follicle Stimulating Hormone (FSH) and its receptor are critical in regulating fertility in humans. FSH is a gonadotropin that is produced in the anterior pituitary gland, and the FSHR is a G protein-coupled receptor (GPCR) found primarily on granulosa cells of the ovaries and Sertoli cells of the testes. When FSH binds to this receptor, it sets off intracellular signaling cascades that regulate gonadal functions and the maturation of gametes. Abnormalities in FSH levels and problems with the FSHR can lead to reproductive issues like delayed puberty, oligospermia, azoospermia, and other such problems. Because FSH and its receptor are so important in reproductive functions, scientists have looked to regulate this receptor in order to address issues of birth control and infertility. Controlling this receptor would essentially allow scientists to turn "on" and "off" reproductive functions in humans. According to prior research in our lab, the human FSH receptor has a high affinity to regions in the membrane called lipid rafts. Lipid rafts are specialized locations in the cell membrane that are critical in cell signaling. These regions are believed to be more rigid than the rest of the surrounding membrane, and this rigidity is critically important for signal transduction. Certain complexes can be kept together by a raft, which allows them to assemble and causes signals to be transmitted more quickly. My research focuses on confirming that the FSHR is located in the lipid rafts on the cell membrane using fluorescent imaging and Atomic Force Microscopy (AFM). I have been working to tag proteins in the lipid raft and the receptor itself with different fluorescent colors so that I can see if the locations of the fluorescences align. From there, I will be able to use the AFM to image the cell surface and determine if the region containing the receptor is stiffer than the surrounding membrane. If it is stiffer, this would confirm that it is a lipid raft. This information will be crucial in understanding how this receptor functions and subsequently being able to control it.