Abstract

ZAMUDIO-ARROYO, José Manuel; PENA-RANGEL, María Teresa  and  RIESGO-ESCOVAR, Juan Rafael. Ubiquitination: An organismal dynamic regulatory system. TIP [online]. 2012, vol.15, n.2, pp.133-141. ISSN 1405-888X.

Regulation of genetic expression occurs at different levels, from transcriptional control to post-translational modification of proteins. ubiquitination is one such late process, where target proteins are labeled covalently on a lysine residue with one or more ubiquitin moieties. Ubiquitin itself is a small protein. This mechanism is evolutionarily conserved, present to some degree in bacteria. in eukaryotes, it is organized around three conserved enzymes: E1, an activation enzyme, E2 a conjugation enzyme, and E3, a ligation enzyme. This last class is by far the most diverse, being the main one conferring specificity by guiding E2-ubiquitin complexes to appropriate targets. Depending on the activation domain they possess, there are three classes of E3 enzymes: RiNG-finger, HEcT, and u-box. ubiquitination can signal different outcomes, yet the most studied one is protein degradation via the 26S proteasome. Studying ubiquitination in whole organisms, especially genetic model organisms, confers many advantages, chief among them being the possibility of recording responses of neighboring groups of cells, whether directly affected or not, by the process.

Keywords : Drosophila melanogaster; E3 ligases; proteasome; ubiquitination.

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