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TOR regulates late steps of ribosome maturation in the nucleoplasm via Nog1 in response to nutrients
Author(s) -
Honma Yoshimi,
Kitamura Aiko,
Shioda Ryo,
Maruyama Hironori,
Ozaki Kanako,
Oda Yoko,
Mini Thierry,
Jenö Paul,
Maki Yasushi,
Yonezawa Kazuyoshi,
Hurt Ed,
Ueno Masaru,
Uritani Masahiro,
Hall Michael N,
Ushimaru Takashi
Publication year - 2006
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/sj.emboj.7601262
Subject(s) - nucleoplasm , library science , biology , computer science , genetics , cytoplasm , nucleolus
The protein kinase TOR (target of rapamycin) controls several steps of ribosome biogenesis, including gene expression of rRNA and ribosomal proteins, and processing of the 35S rRNA precursor, in the budding yeast Saccharomyces cerevisiae . Here we show that TOR also regulates late stages of ribosome maturation in the nucleoplasm via the nuclear GTP‐binding protein Nog1. Nog1 formed a complex that included 60S ribosomal proteins and pre‐ribosomal proteins Nop7 and Rlp24. The Nog1 complex shuttled between the nucleolus and the nucleoplasm for ribosome biogenesis, but it was tethered to the nucleolus by both nutrient depletion and TOR inactivation, causing cessation of the late stages of ribosome biogenesis. Furthermore, after this, Nog1 and Nop7 proteins were lost, leading to complete cessation of ribosome maturation. Thus, the Nog1 complex is a critical regulator of ribosome biogenesis mediated by TOR. This is the first description of a physiological regulation of nucleolus‐to‐nucleoplasm translocation of pre‐ribosome complexes.