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The 60S associated ribosome biogenesis factor LSG 1‐2 is required for 40S maturation in Arabidopsis thaliana
Author(s) -
Weis Benjamin L.,
Missbach Sandra,
Marzi Julian,
Bohnsack Markus T.,
Schleiff Enrico
Publication year - 2014
Publication title -
the plant journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.058
H-Index - 269
eISSN - 1365-313X
pISSN - 0960-7412
DOI - 10.1111/tpj.12703
Subject(s) - ribosome biogenesis , eukaryotic small ribosomal subunit , eukaryotic large ribosomal subunit , eukaryotic ribosome , ribosome , ribosomal rna , biology , ribosomal protein , arabidopsis thaliana , microbiology and biotechnology , biogenesis , nucleolus , genetics , mutant , rna , gene , cytoplasm
Summary Ribosome biogenesis involves a large ensemble of trans ‐acting factors, which catalyse rRNA processing, ribosomal protein association and ribosomal subunit assembly. The circularly permuted GTPase Lsg1 is such a ribosome biogenesis factor, which is involved in maturation of the pre‐60S ribosomal subunit in yeast. We identified two orthologues of Lsg1 in Arabidopsis thaliana . Both proteins differ in their C‐terminus, which is highly charged in atLSG1‐2 but missing in atLSG1‐1. This C‐terminus of atLSG1‐2 contains a functional nuclear localization signal in a part of the protein that also targets atLSG1‐2 to the nucleolus. Furthermore, only atLSG1‐2 is physically associated with ribosomes suggesting its function in ribosome biogenesis. Homozygous T‐DNA insertion lines are viable for both LSG1 orthologues. In plants lacking atLSG1‐2 18S rRNA precursors accumulate and a 20S pre‐ rRNA is detected, while the amount of pre‐ rRNA s that lead to the 25S and 5.8S rRNA is not changed. Thus, our results suggest that pre‐60S subunit maturation is important for the final steps of pre‐40S maturation in plants. In addition, the lsg1‐2 mutants show severe developmental defects, including triple cotyledons and upward curled leaves, which link ribosome biogenesis to early plant and leaf development.