positive regulation of protein linear polyubiquitination

Definition

Target type: biologicalprocess

Any process that activates or increases the frequency, rate or extent of protein linear polyubiquitination. [GOC:TermGenie, PMID:21931591]

Positive regulation of protein linear polyubiquitination is a complex process that plays a critical role in various cellular functions, including signal transduction, DNA repair, and protein degradation. It involves the attachment of ubiquitin monomers to target proteins in a linear chain, where the ubiquitin molecules are linked through their methionine 1 (Met1) residue to the lysine 48 (Lys48) residue of the next ubiquitin. This specific linkage forms a linear polyubiquitin chain, distinct from other ubiquitin chain topologies.

The process starts with the activation of ubiquitin by the E1 ubiquitin-activating enzyme, which utilizes ATP hydrolysis to generate a high-energy thioester bond between ubiquitin and the E1 enzyme. The activated ubiquitin is then transferred to an E2 ubiquitin-conjugating enzyme, another key player in this pathway.

E3 ubiquitin ligases, the final players in this complex, are responsible for recognizing the target protein and facilitating the transfer of the ubiquitin from the E2 enzyme to the target protein. E3 ligases often exhibit substrate specificity, recognizing specific protein motifs or post-translational modifications on the target protein.

Linear polyubiquitination can be regulated at multiple levels. The expression and activity of E1, E2, and E3 enzymes can be modulated by various mechanisms, including post-translational modifications, protein-protein interactions, and transcriptional regulation.

The formation of linear polyubiquitin chains can be further regulated by deubiquitinases, enzymes that remove ubiquitin chains from proteins. These enzymes can specifically target linear ubiquitin chains, controlling the duration and extent of linear polyubiquitination.

The process of positive regulation of protein linear polyubiquitination involves the enhancement or stimulation of the formation of linear polyubiquitin chains. This can be achieved through increased activity of E1, E2, and E3 enzymes, decreased activity of deubiquitinases, or changes in the accessibility of the target protein to ubiquitination.

Overall, the positive regulation of protein linear polyubiquitination is a tightly regulated process that involves a complex interplay of multiple proteins and enzymes. This precise regulation ensures that linear polyubiquitination occurs only when and where it is needed, allowing for the proper functioning of cellular processes and the maintenance of cellular homeostasis.'
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Proteins (1)

Compounds (12)