Use of CRISPR to Develop a Follicle Stimulating Hormone Receptor Knockout in Human Granulosa Cells to Study Lipid Raft Residency

Human follicle stimulating hormone (hFSH) is a protein hormone responsible for stimulating the gonads and is necessary for regulating reproductive systems in both females and males. The actions of hFSh are carried out by the hFSH receptor (hFSHR), a seven transmembrane receptor that belongs to the G protein-coupled receptor family. Once FSH activates its receptor, the G protein inside the cell that is associated with the receptor is activated and starts a cascade of signaling that results in activation of protein kinase A (PKA) and the p44/42 MAP kinase (MAPK). The activation of these secondary proteins is responsible for follicular stimulation in females and gametogenesis in males and females. Previous work in the Cohen Lab has shown that hFSHR is located in cholesterol and sphingolipid enriched microdomains referred to as lipid rafts. These microdomains are detergent resistant membranes that “float” in sucrose gradients. Current research is focused on the relevance of hFSHR lipid raft residency in the human granulosa cell line hGrC1; focusing in particular on the activation of signal transduction pathways by hFSHR. To study this in more detail, we are creating a human granulosa cell line where the hFSHR gene has been deleted, known as a knockout mutant. CRISPR (Clustered Regularly Interspaced Short Palindromic Repeats) is a revolutionary gene editing technique that can create knockouts by precisely targeting a 20 nucleotide sequence of the genome using the Cas9 protein. This knockout line will enable us to study lipid raft residency and signaling of mutant hFSHR proteins in the native cell background. By studying the regulation of hFSHR signaling we hope to learn more about the receptor’s function and identify new ways to modulate the receptor for novel approaches to contraception or treatment of infertility.