U3 snoRNP and Rrp5p associate independently with Saccharomyces cerevisiae 35S prerRNA, but Rrp5p is essential for association of Rok1p. Nucleic Acids Res (2004)

Content Provider	CiteSeerX
Author	Vos, Harmjan R. Bax, Ralph Faber, Alex W. Vos, Jan C. Raué, Hendrik A.
Abstract	Biogenesis of eukaryotic ribosomal subunits pro-ceeds via a series of precursor ribonucleoprotein particles that correspond to different stages in the maturation pathway. The different pre-ribosomal particles each contain a distinct complement of non-ribosomal, trans-acting factors that are crucial for correct and efficient progress of the maturation process. Although in recent years we have gained considerable insight into the composition of the pre-ribosomal particles, our knowledge how the ordered association with and their dissociation from the pre-ribosome of these trans-acting factors is controlled is still quite limited. Here, we have stu-died the mutual dependence between three of these factors,Rrp5p, U3 snoRNPand Rok1p, all essential for the early stages of pre-rRNA processing/assembly, for association with the 35S pre-rRNA in Saccharomyces cerevisiae. Using co-immunopreci-pitation assays, we show that Rrp5p and U3 snoRNP associate independently of each other and that the two factors do not detectably interact prior to incorporation into the pre-ribosome. In contrast, association of the putative RNA helicase Rok1p, which is known to genetically interact with Rrp5p, is absolutely dependent on the presence of the latter protein but does not require U3.
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Publisher Date	2004-01-01
Access Restriction	Open
Content Type	Text