Dcp1a and GW182 Induce Distinct Cellular Aggregates and Have Different Effects on microRNA Pathway

Area of Science:

• Cell Biology
• Molecular Biology
• RNA Biology

Background:

• Processing bodies (P-bodies) are cellular sites for mRNA decay, linked to RNA interference and microRNA (miRNA)-mediated translational repression.
• Understanding the roles of specific protein aggregates in these processes is crucial for deciphering gene regulation.

Purpose of the Study:

• To investigate the distinct effects of overexpressed Dcp1a and GW182 on cytoplasmic aggregate formation.
• To determine their influence on the miRNA pathway and protein translation.

Main Methods:

• Overexpression of Dcp1a, GW182, and G3BP1 to induce cytoplasmic aggregates.
• Recruitment analysis of small RNAs and protein localization (DDX6, Ago2) within these aggregates.
• Assessment of protein translation suppression and miRNA-mediated target regulation.

Main Results:

• Small RNAs were recruited into P-bodies and Dcp1a/GW182 aggregates.
• Overexpressed Dcp1a, but not GW182, colocalized with DDX6 and suppressed translation.
• Stress granules induced by G3BP1 overexpression also recruited small RNAs and repressed translation.
• Endogenous Ago2 did not colocalize with Dcp1a, GW182, or G3BP1 aggregates.
• miRNA-mediated target regulation was enhanced by Dcp1a and G3BP1-induced granules.

Conclusions:

• Overexpressed Dcp1a and GW182 form distinct cytoplasmic aggregates with unique roles in the miRNA pathway.
• These aggregates differentially impact small RNA recruitment, protein translation, and miRNA efficacy.