Poster abstracts

Poster number 62 submitted by Arlie Rinaldi

Uncovering the function of the Nob1: a putative endonuclease involved in ribosome biogenesis

Arlie Rinaldi (Department of Chemistry, University of Michigan), Katrin Karbstein (Department of Chemistry, University of Michigan)

Abstract:
Eukaryotic ribosome assembly is a highly intricate and complex process that includes modification and folding of the 4 ribosomal RNAs (rRNA) as well as binding of the 78 ribosomal proteins. Ribosome assembly requires the action of more than 170 protein factors. [1] Despite the fact that these proteins are highly conserved within eukaryotes and essential for life, their function remains poorly understood. In the yeast Saccharomyces cerevisiae, a protein called Nob1 is required for cell viability. Depletion of this protein leads to a defect in 40S, or small subunit processing. [2] Specifically, it results in accumulation of 20S rRNA, the precursor to 18S rRNA, which is the primary rRNA component of the small subunit in yeast. Because Nob1 contains a PIN domain, it is believed to be the endonuclease responsible for the D-site cleavage to produce the mature 18S rRNA. [3] In addition to the PIN domain, Nob1 also contains a zinc-finger domain, which is a well-known RNA binding domain. Our lab has successfully produced multiple point mutations in these two domains to test the in vivo and in vitro effects of deleting these specific residues. These results, in conjunction with the wild-type data, will provide a clear insight into the function of this putative ribosomal protein factor.

References:
[1] Fromont-Racine, M.; Senger, B.; Saveanu, C.; Fasiolo, F. Gene 2003, 313, 17-42.
[2] Fatica, A.; Oeffinger, M.; Dlakic, M.; Tollervey, D. Mol. Cell. Biol. 2003, 23, 1798-1807.
[3] Fatica, A.; Tollervey, D.; Dlakic, M. RNA 2004, 10, 1698-1701.

Keywords: ribosome, small subunit