biostudies-literatureLau BEuropean Research CouncilDeutsche ForschungsgemeinschaftUniversidad de SalamancaUniversité de FribourgCanton de Fribourg111684https://www.ebi.ac.uk/biostudies/studies/S-EPMC9715914biostudies-literatureUnknown41(8)Ribosome synthesis begins in the nucleolus with 90S pre-ribosome construction, but little is known about how the many different snoRNAs that modify the pre-rRNA are timely guided to their target sites. Here, we report a role for Cms1 in such a process. Initially, we discovered CMS1 as a null suppressor of a nop14 mutant impaired in Rrp12-Enp1 factor recruitment to the 90S. Further investigations detected Cms1 at the 18S rRNA 3' major domain of an early 90S that carried H/ACA snR83, which is known to guide pseudouridylation at two target sites within the same subdomain. Cms1 co-precipitates with many 90S factors, but Rrp12-Enp1 encircling the 3' major domain in the mature 90S is decreased. We suggest that Cms1 associates with the 3' major domain during early 90S biogenesis to restrict premaCell reportsCms1 coordinates stepwise local 90S pre-ribosome assembly with timely snR83 release.PMC9715914741781ADG 741781BE 1814/15-1ADG 885711885711Kressler DBeine-Golovchuk OJady BHurt EBeckmann RKiss TKornprobst MLau BCheng JfalseCms1 coordinates stepwise local 90S pre-ribosome assembly with timely snR83 release.Ribosome synthesis begins in the nucleolus with 90S pre-ribosome construction, but little is known about how the many different snoRNAs that modify the pre-rRNA are timely guided to their target sites. Here, we report a role for Cms1 in such a process. Initially, we discovered CMS1 as a null suppressor of a nop14 mutant impaired in Rrp12-Enp1 factor recruitment to the 90S. Further investigations detected Cms1 at the 18S rRNA 3' major domain of an early 90S that carried H/ACA snR83, which is known to guide pseudouridylation at two target sites within the same subdomain. Cms1 co-precipitates with many 90S factors, but Rrp12-Enp1 encircling the 3' major domain in the mature 90S is decreased. We suggest that Cms1 associates with the 3' major domain during early 90S biogenesis to restrict prema2022-01-01T00:00:00Z2022 Nov2026-05-27T18:52:04.344Z2025-04-06T14:07:36.886ZS-EPMC97159143641786410.1016/j.celrep.2022.111684