Direct interaction between Utp8p and Utp9p contributes to rRNA processing in budding yeast.
The small subunit (SSU) processome is an evolutionarily conserved ribonucleoprotein (RNP) complex that consists of U3 snoRNA and at least 40 protein components. The SSU processome is required for the generation of 18S rRNA in the budding yeast Saccharomyces cerevisiae. In this study we demonstrate that two essential components of the SSU processome, Utp8p and Utp9p, must interact directly for the SSU processome to function properly. Disruption of the Utp8p-Utp9p interaction by mutation of the respective interacting domain led to a compromised ability of yeast cells to process 35S pre-rRNA into 18S pre-rRNA. Loss of the Utp8p-Utp9p interaction also led to a decrease in the amount of Utp8p that interacted with U3 small nucleolar RNAs (snoRNAs) but did not affect the amount of Utp9p bound to U3 snoRNA, suggesting that Utp8p associates with the SSU processome by virtue of its interaction with Utp9p. Together, our data support a model where Utp8p and Utp9p must interact directly and functionally in the U3-containing SSU processome for optimal rRNA biosynthesis to occur in budding yeast.
Department of Microbiology, National Taiwan University, Taipei, Taiwan.
Yu-Ching
YC
Huang
Shun-Fu
SF
Tseng
Hung-Ji
HJ
Tsai
Brian A
BA
Lenzmeier
Shu-Chun
SC
Teng
D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D012322:RNA Precursors / Q000096:biosynthesis; D012335:RNA, Ribosomal / Q000096:biosynthesis*; D012337:RNA, Ribosomal, 18S / Q000096:biosynthesis; D020537:RNA, Small Nucleolar / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
D009687:Nuclear Proteins; D012322:RNA Precursors; D012335:RNA, Ribosomal; D012337:RNA, Ribosomal, 18S; D020537:RNA, Small Nucleolar; C117378:RNA, U3 small nucleolar; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; C524393:Utp8 protein, S cerevisiae; C547588:Utp9 protein, S cerevisiae