title: [Recombinant proteasomal alpha-type subunits exhibit endoribonuclease activity].
abstract: 26S proteasome is a multi-subunit protein complex that consists of the regulatory 19S and the catalytic 20S subcomplexes. The major cellular function of the proteasome is protein degradation. It has been found recently that the 20S particle, besides its proteolytic activity, also possesses endoribonuclease activity. The latter is mediated by two alpha-type subunits (alpha1 and alpha5). In this report we have analyzed the remaining alpha-type subunits for their ability to hydrolyze RNA. We found that all of the recombinant subunits tested exhibited endoribonuclease activity which depended on the origin of RNA and the presence of bivalent ions in the reaction. These results indicate that the endoribonuclease activity of proteasomes may play an important role in cellular metabolism of RNA.
authors.forename: O A
authors.initials: OA
authors.lastname: Fedorova
authors.forename: T N
authors.initials: TN
authors.lastname: Moiseeva
authors.forename: A G
authors.initials: AG
authors.lastname: Mittenberg
authors.forename: N A
authors.initials: NA
authors.lastname: Barlev
mesh_terms: D004722:Endoribonucleases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D006801:Humans; D020014:K562 Cells; D046988:Proteasome Endopeptidase Complex / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D012313:RNA / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D011994:Recombinant Proteins; D012313:RNA; D004722:Endoribonucleases; D046988:Proteasome Endopeptidase Complex; C119011:26S proteasome non-ATPase regulatory subunit 13