Answer:
The endomembrane system is defined as the system made up of several different membranes within a eukaryotic cell. the membranes are resposnible and helps to perform the cell other functions.
Endomembrane system provides a mechanism for transporting proteins from the rough endoplasmic reticulum to the Golgi apparatus through COPII-coated transport vesicles. COPII-coated transport vesicles rise from ER exit sites which are free from ribosomes boundation.
Hence, COPII-coated transport vesicles are responsible for transposrting protein endomembrane system between Rough er and golgi apparatus.