The signal-recognition particle is not the only factor that evaluates the authenticity of endoplasmic reticulum (ER) signal sequences in proteins. The Sec61 complex is also able to recognize the signal sequences and "opens" after binding to them.
Secretory proteins are normally. synthesized by ribosomes bound to a special type of this compartment.". B. involved in the transport of proteins with the first signal sequence but not the second one. A geneticist has devised a strategy to study protein translocation into the endoplasmic reticulum (ER) in yeast cells.