The path from nucleolar 90S to cytoplasmic 40S pre-ribosomes.

ABSTRACT: Recent reports have increased our knowledge of the consecutive steps during 60S ribosome biogenesis substantially, but 40S subunit formation is less well understood. Here, we investigate the maturation of nucleolar 90S pre-ribosomes into cytoplasmic 40S pre-ribosomes. During the transition from 90S to 40S particles, the majority of non-ribosomal proteins (approximately 30 species) dissociate, and significantly fewer factors associate with 40S pre-ribosomes. Notably, some of these components are part of both early 90S and intermediate 40S pre-particles in the nucleolus (e.g. Enp1p, Dim1p and Rrp12p), whereas others (e.g. Rio2p and Nob1p) are found mainly on late cytoplasmic pre-40S subunits. Finally, temperature-sensitive mutants mapping either in earlier (enp1-1) or later (rio2-1) componen

SUBMITTER: Schafer T 

PROVIDER: S-EPMC151049 | biostudies-literature | 2003 Mar

REPOSITORIES: biostudies-literature