P-bodies act as dynamic control hubs for RNA processing and storage

Area of Science:

• Cell Biology
• Molecular Biology
• Yeast Genetics

Background:

• Processing bodies (PBs) are cytoplasmic granules involved in mRNA metabolism.
• Their precise role in cellular stress response, particularly mRNA storage versus decay, remains incompletely understood.

Purpose of the Study:

• To investigate the dynamic localization and fate of mRNAs within PBs during glucose depletion in yeast.
• To differentiate the roles of PBs in mRNA decay and storage under stress conditions.

Main Methods:

• Utilized SH-linked alkylation for metabolic sequencing of RNA (SLAM-seq) to track newly synthesized and pre-existing RNAs.
• Analyzed global mRNA fate and PB localization kinetics during induced glucose starvation in yeast.

Main Results:

• Pre-existing mRNAs exhibit diverse localization kinetics within PBs during glucose starvation.
• A subset of transcripts transiently localizes to PBs, aligning with a decay role, but most are not destabilized.
• Many transcripts, both pre-existing and newly synthesized, accumulate in PBs, suggesting a storage function for adaptation.

Conclusions:

• PBs function as dynamic triage sites, directing mRNA fate based on cellular stress.
• The study proposes a model where PBs partition mRNAs into distinct classes with differential fates during nutrient stress.
• PBs play a crucial role in cellular adaptation by managing mRNA populations under stress.