Isolation of U3 snoRNP from CHO cells: a novel 55 kDa protein binds to the central part of U3 snoRNA.
AUTOR(ES)
Lübben, B
RESUMO
U3 snoRNP, the most abundant of the small nucleolar ribonucleoprotein particles (snoRNPs), has previously been demonstrated to participate in pre-rRNA maturation. Here we report the purification of U3 snoRNP from CHO cells using anti-m3G-immunoaffinity and mono Q anion-exchange chromatography. Isolated U3 snoRNPs contain three novel proteins, of 15, 50 and 55 kDa respectively. These proteins may represent core U3 snoRNP proteins whose binding mediates the association of other proteins, such as fibrillarin, that are lost during purification. Using a rabbit antiserum raised against the 55 kDa protein, and an in vitro reconstitution assay, we have localised the 55 kDa protein binding site on the U3 snoRNA. Stable binding of the 55 kDa protein requires sequences located between nucleotides 97 and 204 of the human U3 snoRNA, including the evolutionarily conserved B and C sequence motifs.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=310574Documentos Relacionados
- Interaction of the U3-55k protein with U3 snoRNA is mediated by the Box B/C motif of U3 and the WD repeats of U3-55k
- Coupling between snoRNP assembly and 3′ processing controls box C/D snoRNA biosynthesis in yeast
- A U3 snoRNP protein with homology to splicing factor PRP4 and G beta domains is required for ribosomal RNA processing.
- A complex pathway for 3′ processing of the yeast U3 snoRNA
- Rcl1p, the yeast protein similar to the RNA 3′-phosphate cyclase, associates with U3 snoRNP and is required for 18S rRNA biogenesis
