# Assembly of the eukaryotic large ribosomal subunit

> **NIH NIH R01** · ROCKEFELLER UNIVERSITY · 2022 · $339,000

## Abstract

Project Summary
Ribosomes are molecular machines composed of ribosomal RNAs and up to 80 ribosomal proteins.
These large assemblies catalyze protein synthesis in all cells. The long-term goal of this project is to
understand how eukaryotic ribosomes are assembled with the help of more than 200 non-ribosomal
factors as a series of molecular snapshots of assembly intermediates. Combining genetic, biochemical
and mass spectrometry approaches with cryo-EM is an essential step to engineer, trap, isolate and
determine atomic-resolution molecular snapshots of transient assembly intermediates of ribosomal
subunits.
Eukaryotic ribosome assembly can be subdivided into four stages, co-transcriptional assembly events
and initial maturation of small and large ribosomal subunit precursors in the nucleolus, nuclear
maturation of pre-40S and pre-60S particles, nuclear export, and cytoplasmic maturation. While late
events in eukaryotic ribosome assembly are relatively well characterized, the early co-transcriptional
assembly of ribosomal subunits in the nucleolus is still poorly understood. Intermediates at these very
early stages are extremely short-lived and transient and structures of key protein complexes that
catalyze these early events have so far remained elusive.
My laboratory has developed new genetic and biochemical approaches that now enable us to efficiently
tag, trap and isolate early nucleolar assembly intermediates of the large ribosomal subunit. The
synergistic use of these approaches has allowed us to overcome previously intractable biochemical
hurdles, thereby enabling the detailed study of essential early assembly intermediates of the large
ribosomal subunit and the stepwise formation of the polypeptide exit tunnel, one of its functional
centers. Insights from these studies will shed light onto both the mechanisms that are employed during
eukaryotic ribosome assembly to form functional centers as well as how defects in eukaryotic ribosome
assembly can result in human blood disorders, which are collectively termed ribosomopathies.

## Key facts

- **NIH application ID:** 10444518
- **Project number:** 1R01GM143181-01A1
- **Recipient organization:** ROCKEFELLER UNIVERSITY
- **Principal Investigator:** Sebastian Klinge
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $339,000
- **Award type:** 1
- **Project period:** 2022-09-15 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10444518

## Citation

> US National Institutes of Health, RePORTER application 10444518, Assembly of the eukaryotic large ribosomal subunit (1R01GM143181-01A1). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10444518. Licensed CC0.

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