@mariam.ohanyan1: As soon as the new protein chain enters the lumen, it starts folding into its correct 3D shape. Inside the rough ER there are chaperone proteins that help it fold, and enzymes that add modifications. The most important is N-linked glycosylation - adding sugar tags. That tag is critical for stability and for telling the cell where to send the protein next. 3. Quality control: The rough ER is very strict. Misfolded proteins are held by chaperones like BiP/GRP78, given time to try again, and if they still fail, they are sent for degradation through ERAD, ER-Associated Degradation. This prevents toxic proteins from accumulating.

Dr Mariam Ohanyan

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Friday 09 October 2026 02:52:24 GMT