Ubiquitin and proteasomes: Protein regulation by monoubiquitin

  title={Ubiquitin and proteasomes: Protein regulation by monoubiquitin},
  author={Linda A Hicke},
  journal={Nature Reviews Molecular Cell Biology},
  • L. Hicke
  • Published 1 March 2001
  • Biology
  • Nature Reviews Molecular Cell Biology
Multi-ubiquitin chains at least four subunits long are required for efficient recognition and degradation of ubiquitylated proteins by the proteasome, but other functions of ubiquitin have been discovered that do not involve the proteasome. Some proteins are modified by a single ubiquitin or short ubiquitin chains. Instead of sending proteins to their death through the proteasome, monoubiquitylation regulates processes that range from membrane transport to transcriptional regulation. 

Non-traditional Functions of Ubiquitin and Ubiquitin-binding Proteins*

Proteasome-independent functions of ubiquitin are discussed with emphasis on how monoubiquitin and ubiquitIn-binding proteins signal changes in protein location, activity, and interactions with binding partners.

Ubiquitin Proteasome Pathway

The ubiquitin tagging system, the general architecture of the 26S proteasome, as well as some none canonical functions of the26S proteAsome are reviewed.

Ubiquitin: not just for proteasomes anymore.

Signaling through monoubiquitination.

This review highlights recent findings on monoubiquitination as a signaling-induced modification, controlled, among others, by pathways originating from active receptor tyrosine kinases, and reviews the major cellular processes controlled by ubiquitin modification.

Regulated protein turnover: snapshots of the proteasome in action

In a major breakthrough, several groups have determined high-resolution structures of the entire 26S proteasome particle in different nucleotide conditions and with and without substrate using cryo-electron microscopy combined with other techniques, which provide some surprising insights into the functional mechanism of the proteasomes.

Emerging Roles of Ubiquitin in Transcription Regulation

Ubiquitin controls messenger RNA synthesis not only by mechanisms involving ubiquitin-dependent destruction of transcription factors by the proteasome, but also by an intriguing collection of previously unknown and unanticipated mechanisms that appear to be independent of the prote asome.

Illuminating the ubiquitin/proteasome system.

Ubiquitin-mediated proteolysis: an ideal pathway for systems biology analysis.

  • M. Rechsteiner
  • Biology
    Advances in experimental medicine and biology
  • 2004
The ubiquitin pathway, a small, evolutionarily conserved eukaryotic protein that can be attached to a wide variety of intracellular proteins including itself, is ideal for a systems biology approach.



Ubiquitin-dependent protein degradation.

A growing number of cellular regulatory mechanisms are being linked to protein modification by the polypeptide ubiquitin. These include key transitions in the cell cycle, class I antigen processing,

Evolution and function of ubiquitin-like protein-conjugation systems

Newly discovered parallels between the activation of ubiquitin and the biosynthesis of certain enzyme cofactors now hint at the possible evolutionary origins of the Ubiquitin system.

The hPLIC proteins may provide a link between the ubiquitination machinery and the proteasome.

The tails of ubiquitin precursors are ribosomal proteins whose fusion to ubiquitin facilitates ribosome biogenesis

A novel 'chaperone' function for ubiquitin is suggested, in which its covalent association with other proteins promotes the formation of specific cellular structures.

Recognition of the polyubiquitin proteolytic signal

The properties of the substrates studied here implicate substrate unfolding as a kinetically dominant step in the proteolysis of properly folded proteins, and suggest that extraproteasomal chaperones are required for efficient degradation of certain proteasome substrates.

Gettin' down with ubiquitin: turning off cell-surface receptors, transporters and channels.

  • L. Hicke
  • Biology
    Trends in cell biology
  • 1999

A multiubiquitin chain is confined to specific lysine in a targeted short-lived protein.

The experiments with ubiquitin mutated at its Lys48 residue indicate that the multiubiquitin chain in a targeted protein is essential for the degradation of the protein.

The 26S proteasome: a molecular machine designed for controlled proteolysis.

In eukaryotic cells, most proteins in the cytosol and nucleus are degraded via the ubiquitin-proteasome pathway. The 26S proteasome is a 2.5-MDa molecular machine built from approximately 31