The Expression Pattern of PLIN2 in Differentiated Adipocytes from Qinchuan Cattle Analysis of Its Protein Structure and Interaction with CGI-58.

PLIN2 (Perilipin-2) is a protein that can anchor on the membrane of lipid droplets (LDs), playing a vital role in the early formation of LDs and in the regulation of LD metabolism in many types of cells. However, little research has been conducted in cattle adipocytes. In the present study, we found that the expression of PLIN2 mRNA peaks at Day 2 during cattle adipocyte differentiation (p < 0.01), but PLIN2 protein levels maintain high abundance until Day 4 and then decrease sharply. We first built an interaction model using PyMOL. The results of a pull-down assay indicated that bovine PLIN2 and CGI-58 (ABHD5, α/β hydrolase domain-containing protein 5) had an interaction relationship. Furthermore, Bimolecular Fluorescence Complementation-Flow Cytometry (BiFC-FC) was used to explore the function of the PLIN2-CGI-58 interaction. Interestingly, we found that different combined models had different levels of fluorescence intensity; specifically, PLIN2-VN173+CGI-58-VC155 expressed in bovine adipocytes exhibited the highest level of fluorescence intensity. Our findings elucidate the PLIN2 expression pattern in cattle adipocytes, the protein structure and the function of protein⁻protein interactions (PPI) as well as highlight the characteristics of bovine PLIN2 during the early formation and accumulation of lipid droplets.