The 60S associated ribosome biogenesis factor LSG 1‐2 is required for 40S maturation in Arabidopsis thaliana
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 ribos...
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Published in | The Plant journal : for cell and molecular biology Vol. 80; no. 6; pp. 1043 - 1056 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
01.12.2014
|
Online Access | Get full text |
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Summary: | 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. |
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ISSN: | 0960-7412 1365-313X |
DOI: | 10.1111/tpj.12703 |