Question

Retrieval signals, present on the C-terminus of ER resident proteins are captured by the receptors present on __________________

(a) Clathrin-coated vesicles

(b) Golgi complex

(c) COPI-coated vesicles

(d) COPII-coated vesicles

I got this question in an interview for job.

My question is from Cytoplasmic Membrane Systems topic in chapter Cytoplasmic Membrane Systems of Cell Biology

Answer 1

Correct option is (c) COPI-coated vesicles

For explanation I would say: The COPI-coated transport vesicles operate in the retrograde direction and are responsible for retention of proteins that reside in the ER membrane or lumen and are accidentally carried away by the Golgi complex. Such proteins possess retrieval signals at their C-terminus which is captured by receptors on the COPI-coated vesicles, which transport them back to the endoplasmic reticulum.