NOPCHAP1 is a PAQosome cofactor that helps loading NOP58 on RUVBL1/2 during box C/D snoRNP biogenesis.
Fiche publication
Date publication
décembre 2020
Journal
Nucleic acids research
Auteurs
Membres identifiés du Cancéropôle Est :
Pr CHARPENTIER Bruno, Dr MANIVAL Xavier
Tous les auteurs :
Abel Y, Paiva ACF, Bizarro J, Chagot ME, Santo PE, Robert MC, Quinternet M, Vandermoere F, Sousa PMF, Fort P, Charpentier B, Manival X, Bandeiras TM, Bertrand E, Verheggen C
Lien Pubmed
Résumé
The PAQosome is a large complex composed of the HSP90/R2TP chaperone and a prefoldin-like module. It promotes the biogenesis of cellular machineries but it is unclear how it discriminates closely related client proteins. Among the main PAQosome clients are C/D snoRNPs and in particular their core protein NOP58. Using NOP58 mutants and proteomic experiments, we identify different assembly intermediates and show that C12ORF45, which we rename NOPCHAP1, acts as a bridge between NOP58 and PAQosome. NOPCHAP1 makes direct physical interactions with the CC-NOP domain of NOP58 and domain II of RUVBL1/2 AAA+ ATPases. Interestingly, NOPCHAP1 interaction with RUVBL1/2 is disrupted upon ATP binding. Moreover, while it robustly binds both yeast and human NOP58, it makes little interactions with NOP56 and PRPF31, two other closely related CC-NOP proteins. Expression of NOP58, but not NOP56 or PRPF31, is decreased in NOPCHAP1 KO cells. We propose that NOPCHAP1 is a client-loading PAQosome cofactor that selects NOP58 to promote box C/D snoRNP assembly.
Référence
Nucleic Acids Res. 2020 Dec 24;: