Abstract Body: Atherosclerosis results from the buildup of cholesterol-filled plaques in artery walls. Accumulation of cholesterol from oxidized low-density lipoprotein (oxLDL) leads to the formation of macrophage foam cells, a process that is mediated by CD36, a scavenger receptor that serves as the primary receptor for oxLDL. The structure of full-length CD36 has not been resolved, nor have the details or role of quaternary structure been fully elucidated. Studies have shown that CD36 can form homodimers and multimers in some cell types. We hypothesize that the CD36 oligomerization is mediated by a putative glycine dimerization motif, G¹²XXXG¹⁶XXXA²⁰XXG²³ (GXXXG), in the N-terminal transmembrane domain. This motif was identified by computational modeling and a role in oligomerization was suggested by studies using CD36 peptides. However, no studies have investigated CD36 homo-oligomerization using full-length protein. To address this knowledge gap, we created a full-length human CD36 construct with key glycine residues in the motif mutated to either alanine (A3) or isoleucine (I4). CD36 wild-type (WT), CD36-A3, or CD36-I4 were transfected into HEK293 cells. Cell surface expression was assessed by biotinylation assays. While CD36-A3 demonstrated similar total and cell surface expression compared to CD36-WT, CD36-I4 had significantly reduced total and cell surface expression. To assess oligomerization, we separated lysates using perfluorooctanoic acid (PFO) gel electrophoresis, which contains a mild detergent and no reducing agents to maintain oligomeric species. Both CD36-WT and CD36-A3 separated into dimers and higher-order oligomers, indicating that CD36 oligomerization was not disrupted by the A3 mutation in the GXXXG motif. However, CD36-I4 showed loss of higher-order oligomers. Binding and uptake of oxLDL was assessed by incubating CD36-expressing cells with DiI-oxLDL at 4 and 37°C. While CD36-A3 cells had similar binding and uptake to CD36-WT, CD36-I4 had 67.1% reduced oxLDL binding and 80.6% reduced uptake of oxLDL, likely reflective of the lower expression levels. Since CD36-A3 did not disrupt CD36 homo-oligomerization, we will next investigate the role of this motif in hetero-oligomerization of CD36 to other potential binding partners. Understanding the higher-order structure of CD36 and how it impacts function will allow us to target CD36 to prevent foam cell formation and atherosclerosis.