RACK1 on and off the ribosome

Area of Science:

• Molecular Biology
• Biochemistry

Background:

• Receptor for activated C kinase 1 (RACK1) is a eukaryote-specific ribosomal protein (RP).
• RACK1's roles on and off the ribosome suggest potential instability as a fluorescent tag.
• The kinetics of ribosomal protein exchange remain unclear.

Purpose of the Study:

• To engineer fluorescently labeled human ribosomes using RACK1.
• To investigate the stability and dynamics of RACK1 on human ribosomes in vitro.
• To provide tools for single-molecule analysis of human translation.

Main Methods:

• Engineering fluorescently labeled human ribosomes via RACK1.
• Applying bulk and single-molecule biochemical analyses.
• Tracking RACK1 association and dissociation from ribosomes.

Main Results:

• Engineered human ribosomes with fluorescently labeled RACK1.
• Demonstrated RACK1 readily reassociates with the ribosome.
• Showed RACK1 remains stably bound to the ribosome for hours in vitro with limited conformational dynamics.

Conclusions:

• RACK1 is a stable ribosomal protein tag for engineering fluorescent ribosomes.
• Provides insights into the biochemical basis of ribosomal protein exchange.
• Offers novel tools for single-molecule studies of human translation.