Related Experiment Video
Updated: Feb 7, 2026
11:22
Quantitative Analysis of Alternative Pre-mRNA Splicing in Mouse Brain Sections Using RNA In Situ Hybridization Assay
Published on: August 26, 2018
9.3K
SF3B1 Phosphorylation Prompts U2AF2 Dissociation for Widespread Control of pre-mRNA Splicing
Christopher L Kirchhoff1, Hannah R Powell1, Justin W Galardi1,2
1Center for RNA Biology and Department of Biochemistry and Biophysics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
Biorxiv : the Preprint Server for Biology
|February 6, 2026
Summary
Phosphorylation of splicing factor SF3B1 reduces its binding to U2AF2, a key step for pre-mRNA splicing progression. This phosphorylation acts as a switch, enabling spliceosome disassembly and ensuring proper gene expression.
Area of Science:
- Molecular Biology
- RNA Biology
- Biochemistry
Background:
- Pre-mRNA splicing is crucial for gene expression, involving dynamic protein modifications.
- Phosphorylation of spliceosome components regulates spliceosome assembly, activation, and disassembly.
- The functional roles of SF3B1 phosphorylation remain incompletely understood.
Purpose of the Study:
- To investigate the functional and mechanistic roles of SF3B1 phosphorylation.
- To elucidate the impact of SF3B1 phosphorylation on its interaction with U2AF2.
- To understand how SF3B1 phosphorylation influences pre-mRNA splicing.
Main Methods:
- Determined crystal structures of SF3B1 and U2AF2.
- Utilized site-directed mutagenesis to create SF3B1 phosphorylation variants.
- Analyzed splice site usage changes in response to SF3B1 phosphorylation status.
Main Results:
- SF3B1 phosphorylation significantly decreases its association with U2AF2.
- Crystal structures reveal electrostatic repulsion between phosphorylated SF3B1 and U2AF2.
- SF3B1 phosphorylation variants altered thousands of splice sites, particularly those recognized by U2AF2.
Conclusions:
- SF3B1 phosphorylation acts as a regulatory mechanism controlling U2AF2 dissociation.
- This phosphorylation event is essential for the progression of pre-mRNA splicing.
- SF3B1 phosphorylation plays a widespread role in regulating splice site selection.
Related Concept Videos
01:36Pre-mRNA Processing: RNA Splicing
7.0K
7.0K
02:01pre-mRNA Processing
57.6K
In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl...
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl...
57.6K
02:41Chromatin Structure Regulates pre-mRNA Processing
8.2K
In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell.
The chromatin structure, especially...
The chromatin structure, especially...
8.2K
01:35Pre-mRNA Processing: Modification of pre-mRNA Ends
15.3K
In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps...
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps...
15.3K
02:18Alternative RNA Splicing
25.2K
Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity.
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...
25.2K
02:27Nonsense-mediated mRNA Decay
11.9K
The Upf proteins that carry out nonsense-mediated decay (NMD) are found in all eukaryotic organisms, including humans. Each protein has an individual role, but they need to work in collaboration. Upf1 is an ATP-dependent RNA helicase that unwinds the RNA helix. Because Upf1 can unwind any RNA, Upf2 and Upf3 are required to help Upf1 discriminate between nonsense and normal mRNAs.
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
11.9K