MEMBRANE FLUIDITY HOMEOSTASIS: THE PAQR-2/ADIPOR PATHWAY IN C. ELEGANS AND MAMMALIAN CELLS

Using C. elegans, we have discovered the first sensor/regulator of membrane homeostasis in animals: it is composed of two proteins, PAQR-2 and IGLR-2, which are homologs of the mammalian ADIPOR1/2 proteins and of LRIG-type proteins, respectively.

This protein complex is essential for C. elegans to regulate membrane composition when challenged by low temperature or by diets rich in saturated fatty acids (SFAs).

This is a fundamental discovery in cell biology and explains our ability to eat saturated fats.AIMThe aim is to better understand how PAQR-2/IGLR-2 function in C. elegans, and to extend our findings to the mammalian ADIPORs.PROJECT OVERVIEW We will leverage forward genetics in C. elegans, our own CRISPR/Cas9-generated HEK293 AdipoR2 KO cell line, and ADIPOR1/2 and TLCD1/2 KO mice to better define the molecular basis of PAQR-2/ADIPOR functions and their in vivo roles.

The experimental approaches include: structure-function studies in transgenic worms, immunoprecipitation/mass-spec identification of PAQR-2 and ADIPOR interaction partners, measurements of membrane fluidity using FRAP and Laurdan methods, lipidomics, localization of proteins in vivo using fluorescence microscopy and genome wide screens using CRISPR/Cas9 gRNA libraries.

SIGNIFICANCE This project sheds will reveal fundamental mechanisms responsible for membrane homeostasis and shed new light how animals, including us, can thrive on diets that vary greatly in their fatty acid composition.