RRP9 Recombinant Rabbit mAb (S-4838-24)

RRP9, also known as U3-55K, is an evolutionarily highly conserved RNA-binding protein belonging to the WD-repeat protein family, playing an indispensable core role in eukaryotic ribosome biogenesis. Structurally, RRP9 contains an N-terminal region and a typical seven-bladed β-propeller WD domain folded from 7 WD repeats, with a bipartite nuclear localization signal at its N-terminus directing it into the nucleolus. The most important function of RRP9 is serving as a specific component of the U3 snoRNP (small nucleolar ribonucleoprotein) complex, where it recognizes and binds to the unique B/C motifs on U3 snoRNA through its WD domain, with this binding being dependent on the prior action of Snu13 protein. As a key member of the small subunit processome (SSU processome), RRP9 works in concert with U3 snoRNA and is essential for 18S ribosomal RNA processing and the maturation of the small ribosomal subunit. Beyond its core role in fundamental life activities, recent studies have revealed that aberrant RRP9 expression is closely associated with diseases. It is significantly upregulated in various tumors such as esophageal cancer, and positively correlates with tumor size, lymph node metastasis, and poorer overall survival in patients, suggesting its potential as a promising diagnostic biomarker or therapeutic target in oncology.