Study of the exosome recruitment mechanism in the initial stages of ribosomal biogenesis

Abstract

The Exosome is a protein complex involved in the processes of RNA degradation and processing in eukaryotes. In the cell nucleus, the exosome acts in the processing of rRNAs, with catalytic activity of 3'-5 'exonuclease. This complex interacts with different cofactors in each region of the cell, whose main function is to recruit it for substrate degradation / processing and also to activate the complex. During ribosomal biogenesis, two pre-ribosomal particles are formed, pre-40S and pre-60S, for which the exosome is recruited to process the rRNAs. Our laboratory has already demonstrated that the Nop53 protein recruits the exosome for the pre-60S for the maturation of the 5.8S rRNA. It is not clear, however, what factor is responsible for recruiting the exosome for the pre-40S, which in its early stages, forms the 90S particle. The purpose of this project is to identify the factors responsible for recruiting the exosome for the 90S particle, by controlling the expression of genes for possible recruitment factors and analyzing the location of the exosome subunits in these strains.