CD36 FORMS COVALENTLY ASSOCIATED DIMERS AND MULTIMERS IN PLATELETS AND TRANSFECTED COS-7 CELLS

CD36 is a transmembrane glycoprotein expressed on the surface of a num ber of cell types. The analysis of CD36 from platelets using immunoblo tting, gel filtration, and native PAGE indicated the presence of high molecular complexes exceeding the Mr of monomeric CD36. Experiments us ing transfected COS-7 cells revealed these complexes were homodimers a nd -multimers of CD36. The multimers could be dissociated by treatment with a reducing agent, indicating they were formed by intermolecular cysteine-bridging. Mutagenesis of the cDNA for CD36 implicated the cys teines in the extracellular domain of the molecule. The potential phys iological roles of CD36 multimerisation are discussed. (C) 1997 Academ ic Press.