Ubiquitin tagging marks proteins for destruction by the proteasome to control protein levels.
E1, E2 and E3 enzymes attach a chain of ubiquitin to a lysine of the target; a chain of four or more tags it for the 26S proteasome, which unfolds and cuts it into peptides. E3 ligases confer specificity, with hundreds in humans.
It controls cyclins, transcription factors and misfolded proteins.
Ubiquitin tagging marks proteins for destruction by the proteasome to control protein levels.
Ubiquitin-Proteasome System is one of the 52 topics in Molecular Biology. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Translational Control, Transcription Factors, Mediator Complex.
Bortezomib blocks the proteasome and treats multiple myeloma.
Work through the Beginner topics in Molecular Biology first, such as Central Dogma, DNA Replication, Base Pairing, then return to Ubiquitin-Proteasome System. Advanced topics assume the Intermediate vocabulary.
The closest topics to Ubiquitin-Proteasome System are Translational Control, Transcription Factors, Mediator Complex, microRNA. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Ubiquitin-Proteasome System. To practise the whole of Molecular Biology, use the Molecular Biology quiz.
Ubiquitin-Proteasome System: Ubiquitin tagging marks proteins for destruction by the proteasome to control protein levels. Translational Control: Regulation of protein synthesis rate through initiation factors, upstream open reading frames and mRNA stability. Read both side by side and note what each one explains.
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Translational Control and explain the difference aloud. Finally, take the Molecular Biology quiz and come back to this page for any question you miss.
Regulation of protein synthesis rate through initiation factors, upstream open reading frames and mRNA stability.
🧫 Molecular BiologyProteins that bind specific DNA sequences to turn genes on or off.
🧫 Molecular BiologyA large multi-protein assembly that links enhancer-bound transcription factors to RNA polymerase II.
🧫 Molecular BiologyAbout 22-nucleotide RNAs that fine-tune gene expression by blocking translation or promoting mRNA decay.
🧫 Molecular Biology