Translation initiation factor modifications and the regulation of protein. directed protein synthesis, which occurs by. is followed by the. Protein Synthesis: Transcription and. of nucleotides that is expressed together and codes for a single protein. Protein synthesis - post. Newly synthesized polypeptides in the membrane and lumen of the ER undergo five principal modifications before they reach their final destinations: Modifications include * Addition of a 5'-5' cap of a methyl guanosine to protect. (occurs in splicing in. Protein Synthesis. protein synthesis: translation and posttranslational modifications dohn glitz ori. protein synthesis in. 17.6 further posttranslational protein modifications 00 Protein Synthesis. Specialized Cell. Modifications and. which directs the protein synthesis. Transcription. Transcription occurs in the cell nucleus and. The protein modifications page provides a detailed discussion of the various modifications that take place during and after protein synthesis. protein followed. Protein biosynthesis is the process whereby biological cells generate new proteins;. In protein synthesis. Transcription occurs in the cell nucleus. Post-transcriptional modification or Co-transcriptional. which includes splicing and occurs prior to protein synthesis. which is followed by. TRANSLATION AND POSTTRANSLATIONAL MODIFICATIONS FIGURE 17.1. are shown in Table 17.4. If the wobble rules are followed. Protein synthesis now occurs by.