Role of signal recognition particle in membrane protein targeting

Abstract:

Signal recognition particle (SRP)-dependent co-translational protein targeting is a conserved pathway across all kingdoms of life. It couples the translation and translocation of nascent peptides. Over 30% of newly synthesized peptides are delivered to the correct localization by SRP. Recent studies have demonstrated that SRP suppressors can circumvent the SRP requirement in Escherichia coli. The translational control plays a critical role in mediating membrane protein targeting when SRP is absent. This review summarizes how the substrates of SRP translocate to the proper localization with or without SRP, and how the decreased translation rate compensates for the loss of SRP. Furthermore, we discuss the dependence of different proteins on SRP. This review will provide new ideas for further studies about the function of SRP and membrane protein targeting.