Interaction of nucleolin with an evolutionary conserved sequence is required for pre-rRNA primary processing in vitro

• Published in: The Journal of biological chemistry Vol. 275; no. 25; pp. 18845 - 18850
• Main Authors: Ginistry, H., Serin, G., Ghisolfi-Nieto, L., Roger, B., Libante, V., Amalric, F., Bouvet, Philippe
• Format: Journal Article
• Language: English
• Published: American Society for Biochemistry and Molecular Biology 2000
• Subjects: Life Sciences
• ISSN: 0021-9258

The first processing event of the precursor ribosomal RNA (pre-rRNA) takes place within the 5' external transcribed spacer. This primary processing requires conserved cia-acting RNA sequence downstream from the cleavage site and several nucleic acids (small nucleolar RNAs) and proteins trans-acting factors including nucleolin, a major nucleolar protein, The specific interaction of nucleolin with the pre-rRNA is required for processing in vitro. Xenopus laevis and hamster nucleolin interact with the same pre-rRNA site and stimulate the processing activity of a mouse cell extract. A highly conserved 11-nucleotide sequence located 5-6 nucleotides after the processing site is required for the interaction of nucleolin and processing. In vitro selection experiments with nucleolin have identified an RNA sequence that contains the UCGA motif present in the 11-nucleotide conserved sequence, The interaction of nucleolin with pre-rRNA is required for the formation of an active processing complex. Our findings demonstrate that nucleolin is a key factor for the assembly and maturation of pre-ribosomal ribonucleoparticles.