Enp1, a yeast protein associated with U3 and U14 snoRNAs, is required for pre-rRNA processing and 40S subunit synthesis.
Chen, Weidong; Bucaria, Jean; Band, David A.; Sutton, Ann; Sternglanz, Rolf *
[Miscellaneous Article] Nucleic Acids Research. 31(2):690-699, January 15, 2003.

(Format: HTML, PDF)

ENP1 is an essential Saccharomyces cerevisiae gene encoding a 483 amino acid polypeptide. Enp1 protein is localized in the nucleus and concentrated in the nucleolus. An enp1-1 temperature-sensitive mutant inhibited 35S pre-rRNA early processing at sites A0, A1 and A2 as shown by northern analysis of steady state levels of rRNA precursors. Pulse-chase analysis further revealed that the enp1-1 strain was defective in the synthesis of 20S pre-rRNA and hence 18S rRNA, which led to reduced formation of 40S ribosomal subunits. Co-precipitation analysis revealed that Enp1 was associated with Nop1 protein, as well as with U3 and U14 RNAs, two snoRNAs implicated in early pre-rRNA processing steps. These results suggest a direct role for Enp1 in the early steps of rRNA processing.

(C) Copyright Oxford University Press 2003.