Related Experiment Video
Updated: Jun 8, 2026
Novel RNA-Binding Proteins Isolation by the RaPID Methodology
Published on: September 30, 2016
The human Pat1b protein: a novel mRNA deadenylation factor identified by a new immunoprecipitation technique
Antonio Totaro1, Fabrizio Renzi, Giorgio La Fata
1Department of Experimental Neurosciences, Fondazione Santa Lucia, Rome, Italy.
Abstract:
The complex of the yeast Lsm1p-7p proteins with Pat1p is an important mRNA decay factor that is involved in translational shutdown of deadenylated mRNAs and thus prepares these mRNAs for degradation. While the Lsm proteins are highly conserved, there is no unique mammalian homolog of Pat1p. To identify proteins that interact with human LSm1, we developed a novel immunoprecipitation technique that yields virtually pure immunocomplexes. Mass-spec analysis therefore identifies mostly true positives, avoiding tedious functional screening. The method unambiguously identified the Pat1p homolog in HeLa cells, Pat1b. When targeted to a reporter mRNA, Pat1b represses gene expression by inducing deadenylation of the mRNAs. This demonstrates that Pat1b, unlike yPat1p, acts as an mRNA-specific deadenylation factor, highlighting the emerging importance of deadenylation in the mRNA regulation of higher eukaryotes.
Insights
Researchers identified Pat1b as a human homolog of yeast Pat1p, crucial for mRNA decay. Pat1b acts as an mRNA-specific deadenylation factor, regulating gene expression in higher eukaryotes.
Area of Science:
- Molecular Biology
- Gene Regulation
Background:
- The Lsm1p-7p-Pat1p complex is vital for mRNA decay and translational shutdown.
- Mammalian Pat1p homologs were previously unidentified, hindering research into mRNA regulation.
Purpose of the Study:
- To identify proteins interacting with human LSm1.
- To characterize the function of the human Pat1p homolog in mRNA regulation.
Main Methods:
- Developed a novel immunoprecipitation technique for highly pure immunocomplexes.
- Utilized mass spectrometry for protein identification.
- Targeted Pat1b to reporter mRNA to assess its function.
Main Results:
- Unambiguously identified Pat1b as the Pat1p homolog in HeLa cells.
- Demonstrated that Pat1b represses gene expression by inducing mRNA deadenylation.
- Pat1b functions as an mRNA-specific deadenylation factor.
Conclusions:
- Pat1b plays a critical role in mRNA decay and gene regulation in humans.
- Highlights the significance of deadenylation in mRNA regulation in higher eukaryotes.
- Pat1b represents a novel target for understanding post-transcriptional gene control.
