Y-complex architecture revisited: Super resolution microscopy to investigate differences in membrane localization for...

Area of Science:

• Molecular Biology
• Microbiology
• Protein-RNA Interactions

Background:

• Organism survival depends on rapid protein-level adaptation to environmental changes.
• Ribonucleases regulate mRNA stability, influencing protein abundance.
• Bacillus subtilis RNase Y is a key membrane-anchored ribonuclease regulating mRNA.

Purpose of the Study:

• To investigate the localization and interaction dynamics of RNase Y and its associated Y-complex proteins.
• To elucidate the specific role of YaaT, YlbF, and YmcA in Y-complex recruitment and function.
• To understand how environmental factors influence these protein interactions.

Main Methods:

• 3D structured illumination microscopy (SIM) for super-resolution imaging of protein localization.
• Bimolecular fluorescence complementation (BiFC) to detect protein-protein interactions in vivo.
• Biochemical analysis and single-molecule tracking from previous studies.

Main Results:

• YaaT shows distinct, higher membrane-proximal localization compared to YmcA and YlbF.
• YaaT's membrane association strength is dependent on the culture medium.
• BiFC confirmed membrane-proximal interactions between the Y-complex and RNase Y, mediated exclusively by YaaT.

Conclusions:

• The Y-complex is tethered to RNase Y solely through the YaaT protein.
• The Y-complex exhibits dynamic composition, potentially varying with cellular functions.
• These findings reveal a specific mechanism for regulating mRNA stability and protein abundance in Bacillus subtilis.