<prompt> Proteins targeted for destruction in eukaryotes are covalently linked to :ClathrinPepsinLamininUbiquitin  <response>: D i.e. UbiquitinUbiquitine is a small, highly conserved protein 76 amino acid polypeptide, that plays a key role in marking targeting escoing many intracellular protein mainly abnormal newly produced protein and aged normal protein for degradationQ ticket of degradation in multisubunit proteolytic paicles the 26 S proteasome. It is also involved in activation of NFkB, cell cycle regulation degradation of cycles, DNA repair, viral infections etc.Clathrin is a peripheral membrane protein, that helps in endocytosis. Pepsin is proteolytic enzyme secreted by chief cells of stomach and is used for digestion. Laminin is found in extracellular matrix a most abundant glycoprotein present in basement membrane 