Nuclear and cytoplasmic poly(A) binding proteins (PABPs) favor distinct transcripts and isoforms

Area of Science:

• Molecular Biology
• Genomics
• Biochemistry

Background:

• Polyadenylation is crucial for eukaryotic RNA stability, transport, and translation.
• Poly(A)-binding proteins (PABPs) mediate these functions by interacting with poly(A)-tails.
• Nuclear PABP (PABPN) binds nascent poly(A)-tails, while cytoplasmic PABP (PABPC) binds exported transcripts.

Purpose of the Study:

• To investigate the genome-wide distribution of transcripts bound by PABPN and PABPC.
• To analyze the characteristics of RNA populations associated with each PABP isoform.
• To elucidate the roles of PABPN and PABPC in poly(A)-tail dynamics and RNA regulation.

Main Methods:

• Co-immunoprecipitation of endogenous PABPN and PABPC from human cells.
• Analysis of RNA identity, splicing status, poly(A)-tail length, and translation status.
• Genome-wide profiling of PABP-bound RNA populations.

Main Results:

• Many protein-coding and non-coding RNAs show biased association with either PABPN or PABPC.
• PABPN-enriched transcripts were often incompletely spliced with longer poly(A)-tails.
• PABPC-enriched RNAs exhibited longer half-lives and higher translation efficiency.

Conclusions:

• This study provides a comprehensive landscape of RNAs bound by PABPN and PABPC.
• Findings offer new insights into the distinct roles of PABPs in poly(A)-tail metabolism and RNA regulation.
• The data advance the understanding of PABP functions in gene expression control.