A conserved Bcd1 interaction essential for box C/D snoRNP biogenesis

• Authors: Sohail Khoshnevis, Emory University; R. Elizabeth Dreggors, Emory University; Tobias F. R. Hoffmann, Emory University; Homa Ghalei, Emory University
• Journal Title: JOURNAL OF BIOLOGICAL CHEMISTRY
• Volume: Volume 294, Number 48
• Publisher: AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC | 2019-11-29, Pages 18360-18371
• Type of Work: Article | Final Publisher PDF
• Publisher DOI: http://doi.org/10.1074/jbc.RA119.010222
• Subjects: Chemistry, Biochemistry; Biology, Molecular; Biology, Genetics
• Keywords: Science & Technology; Life Sciences & Biomedicine; Biochemistry & Molecular Biology; ribosome assembly; RNA; RNA binding protein; RNA modification; RNA methylation; small nucleolar RNA (snoRNA); ribonuclear protein (RNP); assembly factor; box C; D snoRNA; snoRNP assembly; Bcd1; Snu13; small nucleolar ribonucleoprotein (snoRNP) assembly; zinc finger HIT-type containing 6 (ZNHIT6); ribosome biogenesis; posttranscriptional regulation; rRNA processing; PRE-18S RIBOSOMAL-RNA; SSU PROCESSOME; PROTEIN; HSP90; METHYLATION; PREDICTION; RVB1/RVB2; REGIONS; 15.5K; MOTIF

Abstract

Precise modification and processing of rRNAs are required for the production of ribosomes and accurate translation of proteins. Small nucleolar ribonucleoproteins (snoRNPs) guide the folding, modification, and processing of rRNAs and are thus critical for all eukaryotic cells. Bcd1, an essential zinc finger HIT protein functionally conserved in eukaryotes, has been implicated as an early regulator for biogenesis of box C/D snoRNPs and controls steady-state levels of box C/D snoRNAs through an unknown mechanism. Using a combination of genetic and biochemical approaches, here we found a conserved N-terminal motif in Bcd1 from Saccharomyces cerevisiae that is required for interactions with box C/D snoRNAs and the core snoRNP protein, Snu13. We show that both the Bcd1-snoRNA and Bcd1- Snu13 interactions are critical for snoRNP assembly and ribosome biogenesis. Our results provide mechanistic insight into Bcd1 interactions that likely control the early steps of snoRNP maturation and contribute to the essential role of this protein in maintaining the steady-state levels of snoRNAs in the cell.