Genetic and proteomic analysis of ribosome assembly.
John Woolford, Piyanun Harnpicharnchai, Tiffany Miles, Edward Horsey, Jelena Jakovljevic, Lan Tang
Biological Sciences, Carnegie Mellon University, 4400 Fifth Avenue, Pittsburgh,PA, PA, 15213, USA
During biogenesis of ribosomes, rRNA transcripts and processing intermediates associate with ribosomal proteins as well as assembly factors. These interactions mediate modification and processing of pre-rRNA and proper assembly of ribosomal proteins,both of which require structural rearrangements of the nascent rRNPs. Genetic screens for mutants defective in ribosome biogenesis and more recently, affinity purification of pre-ribosomes, have generated a large catalogue of these assembly factors which are necessary for ribosome assembly and present in pre-ribosomes, but are not present in mature ribosomes. Using these genetic and biochemical tools,we have begun to investigate the following questions: (1) When do assembly factors associate with nascent ribosomes and when are they released? (2) What guides the sequential association and dissociation of assembly factors and ribosomal proteins with pre-ribosomes? Are they recruited via binding to other proteins or RNA or to sites created by the action of other factors? (3) Where is each factor located in assembling ribosomes and with which other factors does it function?.
Return to YGM 2004 Home at SGD