Mutational Analysis of the Nsa2 N-Terminus Reveals Its Essential Role in Ribosomal 60S Subunit Assembly
The ribosome assembly factor Nsa2 is part of the Rea1-Rsa4-Nsa2 interconnected relay on nuclear pre-60S particles that is essential for 60S ribosome biogenesis. Cryo-EM structures depict Nsa2 docked via its C-terminal β-barrel domain to nuclear pre-60S particles, whereas the extended N-term...
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| Main Authors: | , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
30 November 2020
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| In: |
International journal of molecular sciences
Year: 2020, Volume: 21, Issue: 23, Pages: 1-15 |
| ISSN: | 1422-0067 |
| DOI: | 10.3390/ijms21239108 |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.3390/ijms21239108 Verlag, lizenzpflichtig, Volltext: https://www.mdpi.com/1422-0067/21/23/9108 |
| Author Notes: | Helge Paternoga, Alexander Früh, Ruth Kunze, Bettina Bradatsch, Jochen Baßler and Ed Hurt |
| Summary: | The ribosome assembly factor Nsa2 is part of the Rea1-Rsa4-Nsa2 interconnected relay on nuclear pre-60S particles that is essential for 60S ribosome biogenesis. Cryo-EM structures depict Nsa2 docked via its C-terminal β-barrel domain to nuclear pre-60S particles, whereas the extended N-terminus, consisting of three α-helical segments, meanders between various 25S rRNA helices with the extreme N-terminus in close vicinity to the Nog1 GTPase center. Here, we tested whether this unappreciated proximity between Nsa2 and Nog1 is of functional importance. Our findings demonstrate that a conservative mutation, Nsa2 Q3N, abolished cell growth and impaired 60S biogenesis. Subsequent genetic and biochemical analyses verified that the Nsa2 N-terminus is required to target Nsa2 to early pre-60S particles. However, overexpression of the Nsa2 N-terminus abolished cytoplasmic recycling of the Nog1 GTPase, and both Nog1 and the Nsa2-N (1-58) construct, but not the respective Nsa2-N (1-58) Q3N mutant, were found arrested on late cytoplasmic pre-60S particles. These findings point to specific roles of the different Nsa2 domains for 60S ribosome biogenesis. |
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| Item Description: | Gesehen am 18.01.2021 |
| Physical Description: | Online Resource |
| ISSN: | 1422-0067 |
| DOI: | 10.3390/ijms21239108 |