Ubiquitin proteolytic system: focus on SUMO

SUMO and ubiquitin paths converge.

One of the more rapidly expanding fields in cell signalling nowadays is the characterization of proteins conjugated to Ub (ubiquitin) or Ub-like peptides, such as SUMO (small Ub-related modifier). The reversible covalent attachment of these small peptides remodels the target protein, providing new protein-protein interaction interfaces, which can be dynamically regulated given a set of enzymes ...

The small ubiquitin-like modifier (SUMO) and SUMO-conjugating system of Chlamydomonas reinhardtii.

The availability of the complete DNA sequence of the Chlamydomonas reinhardtii genome and advanced computational biology tools has allowed elucidation and study of the small ubiquitin-like modifier (SUMO) system in this unicellular photosynthetic alga and model eukaryotic cell system. SUMO is a member of a ubiquitin-like protein superfamily that is covalently attached to target proteins as a po...

The ubiquitin-proteasome system: focus on the heart.

Proteasomes are the main non-lysosomal multicatalytic protease complexes that are involved in the degradation of most intracellular proteins. The substrate proteins are marked by ubiquitin, which serves as a tag for their regulated proteasomal destruction. One major function of the ubiquitin-proteasome system (UPS) is to prevent accumulation of non-functional, potentially toxic proteins. Moreov...

Expanding SUMO and ubiquitin-mediated signaling through hybrid SUMO-ubiquitin chains and their receptors

Monomeric and polymeric forms of SUMO and ubiquitin are covalently attached to substrates and recognized by effector proteins containing SUMOinteracting motifs (SIMs) or ubiquitininteracting motifs (UIMs), thereby triggering a wide range of biological responses. SUMO and ubiquitin were thought to represent distinct homotypic signals, until recent studies revealed the presence of hybrid SUMO-Ub ...

Editorial: Ubiquitin and Ubiquitin-Relative SUMO in DNA Damage Response