In order for newly - produced secretory or membrane proteins to find their final destination, the proteins have signal - sequences connected to themselves as a form of address tag. (sciencedaily.com)
The signal hypothesis held that proteins carry address tags that are somehow decoded by cells to ensure their safe passage to their final destinations. (vilcek.org)
Walter isolated the six building blocks of the apparatus and dubbed it the signal recognition particle; by the early 1980s, he had demonstrated that the apparatus recruits ribosomes to the ER, latches onto address tags on proteins minted on ribosomes, and transfers proteins to the interior of the ER. (vilcek.org)