Structural component of lipid droplets, which is required for the formation and maintenance of lipid storage droplets. Acylated; primarily with C14, C16 and C18 fatty acids. Phosphorylation at Tyr-232 by isoform 1 of CHKA (CHKalpha2) promotes dissociation from lipid droplets: dissociation is followed by recruitment of autophagosome machinery to lipid droplets and subsequent lipid droplet lipolysis. Belongs to the perilipin family.