title: Proteins directly interacting with mammalian 20S proteasomal subunits and ubiquitin-independent proteasomal degradation.
abstract: The mammalian 20S proteasome is a heterodimeric cylindrical complex (α7β7β7α7), composed of four rings each composed of seven different α or β subunits with broad proteolytic activity. We review the mammalian proteins shown to directly interact with specific 20S proteasomal subunits and those subjected to ubiquitin-independent proteasomal degradation (UIPD). The published reports of proteins that interact with specific proteasomal subunits, and others found on interactome databases and those that are degraded by a UIPD mechanism, overlap by only a few protein members. Therefore, systematic studies of the specificity of the interactions, the elucidation of the protein regions implicated in the interactions (that may or may not be followed by degradation) and competition experiments between proteins known to interact with the same proteasomal subunit, are needed. Those studies should provide a coherent picture of the molecular mechanisms governing the interactions of cellular proteins with proteasomal subunits, and their relevance to cell proteostasis and cell functioning.
authors.affiliation: Departamento de Bioquímica, Instituto de Investigaciones Biomédicas 'Alberto Sols', UAM-CSIC, Facultad de Medicina de la Universidad Autónoma de Madrid, Madrid 28029, Spain. rslanzas@iib.uam.es.
authors.forename: Raúl
authors.initials: R
authors.lastname: Sánchez-Lanzas
authors.affiliation: Departamento de Bioquímica, Instituto de Investigaciones Biomédicas 'Alberto Sols', UAM-CSIC, Facultad de Medicina de la Universidad Autónoma de Madrid, Madrid 28029, Spain. joseg.castano@uam.es.
authors.forename: José G
authors.initials: JG
authors.lastname: Castaño
mesh_terms: D000818:Animals; D006801:Humans; D008322:Mammals / Q000378:metabolism; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism*; D021122:Protein Subunits; D011506:Proteins / Q000378:metabolism*; D025801:Ubiquitin / Q000378:metabolism
chemical_list: D021122:Protein Subunits; D011506:Proteins; D025801:Ubiquitin; D046988:Proteasome Endopeptidase Complex