Genes for E1, E2, and E3 Small Nucleolar RNAs

• Published in: Proceedings of the National Academy of Sciences - PNAS 1993-10, Vol.90 (19), p.9001-9005
• Main Authors: NAG, M. K, THAI, T. T, RUFF, E. A, SELVAMURUGAN, N, KUNNIMALAIYAAN, M, ELICEIRI, G. L
• Format: Article
• Language: English
• Subjects: Analytical, structural and metabolic biochemistry; Animals; Base Sequence; Biochemistry; Biological and medical sciences; Cloning, Molecular; DNA; DNA - analysis; DNA - genetics; expression; Female; Frogs; Fundamental and applied biological sciences. Psychology; Genes; Genomic Library; Genomics; HeLa Cells; Humans; Introns; isolation; man; Mice; Molecular Sequence Data; Nucleic acids; nucleotide sequence; Oocytes; Oocytes - metabolism; Plasmids; Restriction Mapping; Ribonucleic acid; RNA; Rna, ribonucleoproteins; RNA, Small Nuclear - genetics; Sequence Homology, Nucleic Acid; Small nucleolar RNA; snoRNA E1; snoRNA E2; snoRNA E3; Xenopus laevis
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.90.19.9001

We have found earlier three small nucleolar RNA (snoRNA) species, named E1, E2, and E3, that have unique nucleotide sequences and may participate in ribosome formation. The present report shows that there is a monophosphate at the 5' end of each of these three snoRNAs, suggesting that their 5' termini are formed by RNA processing. E1, E2, and E3 human genomic sequences were isolated. Apparently, the E2 and E3 loci are genes for the main E2 and E3 RNA species, based on their full homology, while the E1 locus is a gene for an E1 RNA sequence variant in HeLa cells. These loci do not have any of the intragenic or flanking sequences known to be functional in other genes. The E1 gene is located within the first intron of the gene for RCC1, a protein that regulates onset of mitosis. There is substantial sequence homology between the human E3 gene and flanking regions, and intron 8 and neighboring exons of the gene for mouse translation initiation factor 4AII. Injection of the human E1, E2, and E3 genes into Xenopus oocytes generated sequence-specific transcripts of the approximate sizes of the respective snoRNAs. We discuss why the available results are compatible with specific transcription and processing occurring in frog oocytes.