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Spatial and Temporal Control of Murine Melanoma Initiation from Mutant Melanocyte Stem Cells
Published on: June 7, 2019
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An aggregation-prone mutant of eIF3a forms reversible assemblies escaping spatial control in exponentially growing
Lenka Senohrabkova1,2, Ivana Malcova3, Jiri Hasek4
1Laboratory of Cell Reproduction, Institute of Microbiology of the CAS, Videnska 1083, 14220, Prague 4, Czech Republic.
Current Genetics
|February 5, 2019
Summary
A mutated translation factor, Rpg1-3, forms reversible assemblies that are transmitted to daughter cells. This process depends on the actin cytoskeleton and molecular motor Myo2, offering insights into cellular protein quality control.
Area of Science:
- Cell Biology
- Molecular Biology
- Protein Homeostasis
Background:
- Cells maintain protein homeostasis for vital functions and reproduction.
- Translation is crucial, and its impairment can lead to human brain disorders.
- Protein aggregation is linked to cellular dysfunction.
Purpose of the Study:
- To investigate a mutated translation initiation factor, Rpg1-3, and its aggregation behavior.
- To understand the cellular mechanisms for managing protein complex malfunction.
- To explore the transmission of protein assemblies in yeast cells.
Main Methods:
- Characterization of a mutated eIF3a variant (Rpg1-3) with altered translation efficiency.
- Microscopy to observe the formation and transmission of Rpg1-3-GFP assemblies.
- Investigating the role of the actin cytoskeleton and Myo2 in assembly movement.
- Assessing the impact of chaperone availability (Hsp70, Hsp40) on aggregation.
Main Results:
- Rpg1-3 exhibits attenuated translation efficiency and forms reversible, non-amyloid assemblies.
- These assemblies are transmitted from mother to bud cells, independent of typical aggregate sequestration.
- Bud-directed movement relies on the actin cytoskeleton and the motor protein Myo2.
- Mutations in Rpg1-3 promote aggregation of the eIF3 core complex, exacerbated by limited chaperones.
Conclusions:
- Yeast cells possess mechanisms to handle aggregation of essential protein complexes like eIF3.
- The study reveals novel aspects of protein aggregate transmission and cellular response to protein malfunction.
- Findings provide insights into the interplay between translation factors, protein aggregation, and cellular transport.
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