Question

please answer both

Which of the following is NOT TRUE regarding both M6P and KDEL receptors? Select one: a. They help transport cargo to their proper destinations b. They bind to cargo proteins in the Golgi apparatus. c. They are transported by vesicle budding and fusion, d. They move back-and-forth between different organelles. O e. They release soluble cargo proteins at lower pH. Which of these is NOT a function of the Signal Recognition Particle (SRP) involved in transport of proteins to the ER? of 1.0 . Select one: a. binds to the SPP receptor b. recognizes the ER signal sequence on the nascent polypeptide c.inserts transmembrane domains into the ER membrane d. docks the ribosome to a translocon e. binds to the ribosome and pauses translation

Answer 1

1. They release soluble cargo at lower pH.

KDEL receptors transports proteins from Golgi to ER. As the vesicle that contains these receptors reach ER, due to high pH in the ER, the targeted proteins are released as the vesicle become inactive due to high pH.

M6P receptors transports cargo from Golgi to late endosome. M6P receptor protein binds to its oligosaccharides at pH 6.5 to 7 in the trans Golgi network and releases it at pH 6, which is the pH in the late endosome.

2. Binds to the ribosome and pause translation.

As SRP binds to the SRP receptor it brings the ribosome to the ER membrane. Ribosome resumes translation, and directs the polypeptide chain to the interior of the ER lumen through a pore.