title: The lysine48-based polyubiquitin chain proteasomal signal: not a single child anymore.
abstract: The conjugation of ubiquitin (Ub) to proteins is involved in the regulation of many processes. The modification serves as a recognition element in trans, in which downstream effectors bind to the modified protein and determine its fate and/or function. A polyUb chain that is linked through internal lysine (Lys)-48 of Ub and anchored to an internal Lys residue of the substrate has become the accepted "canonical" signal for proteasomal targeting and degradation. However, recent studies show that the signal is far more diverse and that chains based on other internal linkages, as well as linear or heterologous chains made of Ub and Ub-like proteins and even monoUb, are recognized by the proteasome. In addition, chains linked to residues other than internal Lys were described, all challenging the current paradigm.
authors.affiliation: Cancer and Vascular Biology Research Center, Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel. yelenaiv@tx.technion.ac.il
authors.forename: Yelena
authors.initials: Y
authors.lastname: Kravtsova-Ivantsiv
authors.forename: Thomas
authors.initials: T
authors.lastname: Sommer
authors.forename: Aaron
authors.initials: A
authors.lastname: Ciechanover
mesh_terms: D008239:Lysine / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D025801:Ubiquitin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D025801:Ubiquitin; D046988:Proteasome Endopeptidase Complex; D008239:Lysine