Project Description
Intrinsic membrane proteins recognize and respond to a remarkable variety of stimuli that range from light to molecular ligands such as odorants, hormones, and neurotransmitters. The growing realization that membrane receptors exist and function as oligomers (i.e., supramolecular assemblies) has profound implications for our understanding of receptor-mediated signaling under normal physiological conditions and in disease. Probing the size of the various oligomers of a membrane receptor provides a promising avenue for designing new drugs targeting the oligomers. My lab has developed advanced laser-scanning fluorescence microscopy technology (published in Nature Photonics in 2009), which recently has facilitated the development of a new method, termed fluorescence intensity fluctuation (FIF) spectrometry, which exploits spatial fluctuations of in fluorescence intensity of protein molecules to derive information on the size and abundance of protein oligomers in living cells (Nature Methods, 2019; Nature Methods, 2020). In practice, fluorescence intensity images are acquired of cells expressing proteins of interest tagged with green fluorescent proteins, and a computer program is used to extract intensity distributions, which are then compared to those of fluorescent standards of known oligomeric size. The analysis is performed in the presence and absence of potential drugs, to test their effect on oligomer size.
Tasks and Responsibilites
The student has will perform computer analysis of FIF data obtained from oligomeric standards that we have measured in solution, which are used in our research as references for receptor oligomer size. We have identified this as a critical step in refining and improving our method of analysis. Depending on student's interests, there are also opportunities for biological sciences or biochemistry students to also gain experience in imaging of cells expressing receptors of interest, in the absence and presence of compounds targeting the receptor. The immediate goal is to assess if a compound binds to the receptor and therefore either leads to splitting of existing receptor oligomers or association of monomeric receptors into oligomers. The long-term goal of the experimental work is to help identify and test new drugs. Finally, the project also has an instrumentation-development aspect to it, which would be appropriate for an engineering or physics student.
Desired Qualifications
None