Systematic characterization of the composition and dynamics of processing body-associated mRNAs [dataset 1]

Processing bodies (PBs) are dynamic, membraneless organelles consisting of RNAs and proteins. While PB proteins have been extensively characterized, the methods for systematically profiling PB-associated RNAs are limited. To address this, we developed PB-TRIBE-STAMP, a new tool based on two orthogonal RNA editing enzymes. Simultaneously applying APOBEC1-DDX6 and LSM14A-ADAR2dd, PB-TRIBE-STAMP identified 1,639 and 2,577 PB-associated mRNAs in HCT116 and HEK293T cells, respectively. Further genetic perturbation demonstrated that these transcripts were translationally repressed by PBs. Next, integration of PB-TRIBE-STAMP with long-read sequencing revealed that the PB-associated transcripts possessed shorter poly(A)-tails. Moreover, we established a TRIBE-ID-based tool to characterize the mRNA-PB association at high temporal resolution and unveiled a higher splicing efficiency of PB-associated XBP1 transcripts during unfolded protein response (UPR). Finally, based on sc-LSM14A-TRIBE-ID, we demonstrated the dynamic pattern of mRNA-PB interaction during cell cycle progression. Overall design: LSM14A-TRIBE-ID cells with or without rapamycin treatment were processed for the single-cell RNA sequencing based on the Smart-seq3xpress protocol.