Final answer:
COPI and COPII proteins aid in the budding of transition vesicles from the RER and their fusion with the cis-Golgi, while the protein dynamin is not involved in this process. After fusion, COPI proteins are recycled back to the RER, and proteins within the vesicles undergo further processing in the Golgi.
Step-by-step explanation:
The proteins required for the formation of vesicles from the Rough Endoplasmic Reticulum (RER), such as COPI and COPII, are distinct from the protein dynamin which is often associated with clathrin-mediated endocytosis. The process of vesicular trafficking in cells involves the budding of transition vesicles from the RER with the aid of COPI and COPII coat proteins. These vesicles then fuse with cis-Golgi vesicles, with this fusion event similarly mediated by COP proteins, and finally, COPI proteins detach to be recycled back to the RER. The packaged proteins and membrane proteins continue their processing as they move through the Golgi vesicle stack, including undergoing changes such as terminal glycosylation.