Ribosomes interact with a variety of different protein biogenesis factors that guide newly synthesized proteins to their native 3D shapes and cellular localization. Depending on the type of translated substrate, a distinct set of cotranslational factors must interact with the ribosome in a timely and coordinated manner to ensure proper protein biogenesis. While cytonuclear proteins require cotranslational maturation and folding factors, secretory proteins must be maintained in an unfolded state and processed cotranslationally by transport and membrane translocation factors. Here we explore the specific cotranslational processing steps for cytonuclear, secretory, and membrane proteins in eukaryotes and then discuss how the nascent polypeptide-associated complex (NAC) cotranslationally sorts these proteins into the correct protein biogenesis pathway.

核糖体与多种不同的蛋白质生物合成因子相互作用，引导新合成的蛋白质形成其天然 3D 形状和细胞定位。根据翻译底物的类型，一组不同的共翻译因子必须及时且协调地与核糖体相互作用，以确保适当的蛋白质生物合成。虽然细胞核蛋白需要共翻译成熟和折叠因子，但分泌蛋白必须保持在未折叠状态，并通过运输和膜易位因子进行共翻译加工。在这里，我们探索真核生物中细胞核蛋白、分泌蛋白和膜蛋白的特定共翻译加工步骤，然后讨论新生多肽相关复合物（NAC）如何共翻译将这些蛋白质分类到正确的蛋白质生物发生途径中。