Human RioK3 is a novel component of cytoplasmic pre-40S pre-ribosomal particles

• DOI: 10.4161/rna.18810
• Publication Date: 2012-05-03T17:18:21Z
• Authors: Kamila Baumas; Julien Soudet; Michèle Caizergue...; Marlène Faubladier; Yves Henry; Annie Mougin
• Keywords: Ribosomal protein; ribosome biogenesis; Eukaryotic Ribosome; 5S ribosomal RNA

Maturation of the 40S ribosomal subunit precursors in mammals mobilizes several non-ribosomal proteins, including atypical protein kinase RioK2. Here, we have investigated involvement another member RIO family, RioK3, human ribosome biogenesis. RioK3 is a cytoplasmic that does not seem to shuttle between nucleus and cytoplasm via Crm1-dependent mechanism as RioK2 which sediments with particles sucrose gradient. When small biogenesis impaired by depletion either rpS15, rpS19 or RioK2, concomitant decrease amount observed. Surprisingly, observed dramatic specific increase levels when large impaired. A fraction associated non pre-40S particle components hLtv1 hEnp1 well 18S-E pre-rRNA indicating it belongs bona fide particle. Finally, leads an 21S rRNA precursor 18S production pathway. Altogether, our results strongly suggest novel component pre-ribosomal particle(s) cells, required for normal processing pre-rRNA.