Endoplasmic Reticulum is not a flat out prerequisite in protein amalgamation, as in a reconstituted develop containing mRNA, amino acids, tRNA, ribosome subunits, translation elements, co-elements, and the chemical can create proteins in-vitro (without cell protein union). The way that prokaryotes can incorporate proteins is a proof-of-idea that ER is not a flat out necessity for protein biogenesis.
Having said that, ER unquestionably assumes a noteworthy part in keeping up protein homeostasis. At the point when ER neglects to do that, we experience Unfolded Protein Response (UPR).
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