Which of the following is a ribonucleoprotein required for the delivery of membrane and secretory proteins to the endoplasmic reticulum?
A)protein-conducting channel (PCC)
B)small ubiquitin-related modifier (SUMO)
C)trigger factor
D)calnexin
E)signal recognition particles (SRP)

Question

Quizplus · Accepted Answer

Signal recognition particles (SRP) are ribonucleoproteins that recognize signal peptides on newly synthesized proteins and facilitate their delivery to the endoplasmic reticulum (ER). SRP binds to the signal peptide, halting protein synthesis and delivering the ribosome to the ER membrane, where it interacts with the protein-conducting channel (PCC) to facilitate translocation of the protein into the ER. Therefore, SRP is the correct answer for this question. Choice A, PCC, is also involved in protein translocation into the ER, but it is not a ribonucleoprotein. Choices B, C, and D are not directly involved in protein translocation into the ER.

Which of the Following Is a Ribonucleoprotein Required for the Delivery