Arabidopsis thaliana RHAMNOSE 1 condensate formation drives UDP-rhamnose synthesis

Area of Science:

• Plant biology
• Biochemistry
• Cell biology

Background:

• Rhamnose is vital for plant cell walls.
• The RHAMNOSE1 (RHM1) enzyme synthesizes rhamnose from uridine diphosphate (UDP)-glucose.
• The function and formation of RHM1-containing biomolecular condensates in plants are unknown.

Approach:

• Utilized live imaging, genetics, and biochemical methods.
• Conducted experiments in both Arabidopsis and heterologous systems.
• Investigated the role of RHM1 in condensate formation and enzymatic activity.

Key Points:

• RHAMNOSE1 (RHM1) alone can form enzymatically active biomolecular condensates, termed "rhamnosomes."
• Rhamnosome formation is crucial for the synthesis of UDP-rhamnose.
• These condensates are necessary for proper organ development in plants.

Conclusions:

• Biomolecular condensation plays a novel role in plant metabolism and development.
• Organisms utilize biomolecular condensation to regulate small molecule metabolism.
• Rhamnosomes represent a newly identified class of functional metabolic condensates.