Chaudhuri Anusha, Paul Soumita, Banerjea Mayukh, Das Biswadip
Present Position: Zentrum fǜr Molekulare, Medizin, Institut fǜr Kardiovaskuläre Regeneration, Haus 25B, Goethe-Universität, Theodor-Stern-Kai 7, Universitätsklinikum, 60590 Frankfurt am Main, Germany.
Department of Life Science and Biotechnology, Jadavpur University, 188 Raja S.C. Mullick Road, Kolkata - 700 032, West Bengal, India.
Microb Cell. 2024 May 22;11:155-186. doi: 10.15698/mic2024.05.823. eCollection 2024.
In , polyadenylated forms of mature (and not precursor) small non-coding RNAs (sncRNAs) those fail to undergo proper 3'-end maturation are subject to an active degradation by Rrp6p and Rrp47p, which does not require the involvement of core exosome and TRAMP components. In agreement with this finding, Rrp6p/Rrp47p is demonstrated to exist as an exosome-independent complex, which preferentially associates with mature polyadenylated forms of these sncRNAs. Consistent with this observation, a C-terminally truncated version of Rrp6p (Rrp6p-ΔC2) lacking physical association with the core nuclear exosome supports their decay just like its full-length version. Polyadenylation is catalyzed by both the canonical and non-canonical poly(A) polymerases, Pap1p and Trf4p. Analysis of the polyadenylation profiles in WT and -Δ strains revealed that the majority of the polyadenylation sites correspond to either one to three nucleotides upstream or downstream of their mature ends and their poly(A) tails ranges from 10-15 adenylate residues. Most interestingly, the accumulated polyadenylated snRNAs are functional in the -Δ strain and are assembled into spliceosomes. Thus, Rrp6p-Rrp47p defines a core nuclear exosome-independent novel RNA turnover system in baker's yeast targeting imperfectly processed polyadenylated sncRNAs that accumulate in the absence of Rrp6p.
在[具体情况未提及]中,那些未能经历适当3'端成熟的成熟(而非前体)小非编码RNA(sncRNAs)的聚腺苷酸化形式会被Rrp6p和Rrp47p进行主动降解,这一过程不需要核心外切体和TRAMP组分的参与。与这一发现一致,Rrp6p/Rrp47p被证明以一种独立于外切体的复合物形式存在,它优先与这些sncRNAs的成熟聚腺苷酸化形式结合。与此观察结果相符,一个与核心核外切体缺乏物理关联的Rrp6p的C端截短版本(Rrp6p-ΔC2)与其全长版本一样支持它们的降解。聚腺苷酸化由经典和非经典的聚(A)聚合酶Pap1p和Trf4p催化。对野生型和[缺失菌株未明确]菌株中聚腺苷酸化图谱的分析表明,大多数聚腺苷酸化位点对应于其成熟末端上游或下游的一到三个核苷酸,并且它们的聚(A)尾巴长度在10 - 15个腺苷酸残基之间。最有趣的是,积累的聚腺苷酸化小核RNA在[缺失菌株未明确]菌株中具有功能,并被组装进剪接体。因此,Rrp6p - Rrp47p在酿酒酵母中定义了一个独立于核心核外切体的新型RNA周转系统,该系统靶向在缺乏Rrp6p时积累的加工不完善的聚腺苷酸化sncRNAs。