RRM
2011 Rustbelt RNA Meeting
RRM
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Poster abstracts
Abstract:
Ribosomes are ubiquitous nanomachines that translate mRNA into proteins. Ribosome biogenesis occurs in a precisely controlled step-wise manner during which preribosomal RNAs (pre-rRNAs) undergo highly regulated structural changes, endonucleolytic cleavages and exonucleolytic processing coupled to hierarchical assembly of ribosomal proteins to generate the mature 60S and 40S ribosomal subunits. DEAD-box RNA helicases are a highly conserved group of energy consuming enzymes that utilize ATP to unwind short RNA duplexes and to remodel ribonucleoproteins. In this study, I am taking a comprehensive look at the function of the essential DEAD-box RNA helicase, Has1 in 60S ribosome biogenesis. Has1 copurifies with 66S preribosomes and is required for two consecutive pre-rRNA processing steps to generate the mature 60S ribosomal subunit. To more carefully dissect the function of Has1 in these steps, I am working to precisely map when Has1 enters preribosomes, what factors it depends on to enter preribosomes, what factors and ribosomal proteins depend on Has1 to stably associate with preribosomes or to leave preribosomes, and when Has1 exits preribosomes. We have also identified protein partners of Has1, which may function as Has1 cofactors, activators, or repressors or that may be protein targets that are either stabilized or released from preribosomes by Has1. Additionally, to understand the exact role of Has1 in pre-rRNA processing, cross-linking and analysis of cDNAs is being used to determine the specific RNA binding sites of Has1 on the preribosome. In the future, I plan to use RNA structure probing to understand how Has1 alters preribosomal architecture to generate the mature 60S subunit. Taken together, this systematic approach will allow us to understand the role of this assembly factor in 66S processing steps and will reveal new insights into the mechanisms of 60S ribosome biogenesis.
Keywords: helicase, preribosome, pre-rRNA processing
