Location of the initial cleavage sites in mouse pre-rRNA.
AUTOR(ES)
Bowman, L H
RESUMO
The locations of three cleavages that can occur in mouse 45S pre-rRNA were determined by Northern blot hybridization and S1 nuclease mapping techniques. These experiments indicate that an initial cleavage of 45S pre-rRNA can directly generate the mature 5' terminus of 18S rRNA. Initial cleavage of 45S pre-rRNA can also generate the mature 5' terminus of 5.8S rRNA, but in this case cleavage can occur at two different locations, one at the known 5' terminus of 5.8S rRNA and another 6 or 7 nucleotides upstream. This pattern of cleavage results in the formation of cytoplasmic 5.8S rRNA with heterogeneous 5' termini. Further, our results indicate that one pathway for the formation of the mature 5' terminus of 28S rRNA involves initial cleavages within spacer sequences followed by cleavages which generate the mature 5' terminus of 28S rRNA. Comparison of these different patterns of cleavage for mouse pre-rRNA with that for Escherichia coli pre-rRNA implies that there are fundamental differences in the two processing mechanisms. Further, several possible cleavage signals have been identified by comparing the cleavage sites with the primary and secondary structure of mouse rRNA (see W. E. Goldman, G. Goldberg, L. H. Bowman, D. Steinmetz, and D. Schlessinger, Mol. Cell. Biol. 3:1488-1500, 1983).
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=369996Documentos Relacionados
- Determination of the transcription initiation site of Tetrahymena pyriformis rDNA using in vitro capping of 35S pre-rRNA.
- Three new small nucleolar RNAs that are psoralen cross-linked in vivo to unique regions of pre-rRNA.
- Mutational analysis of an essential binding site for the U3 snoRNA in the 5' external transcribed spacer of yeast pre-rRNA.
- Mutational analysis of an essential binding site for the U3 snoRNA in the 5' external transcribed spacer of yeast pre-rRNA.
- Structural analysis of the human U3 ribonucleoprotein particle reveal a conserved sequence available for base pairing with pre-rRNA.