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Updated: Jun 17, 2026
07:02
Evaluation of Exon Inclusion Induced by Splice Switching Antisense Oligonucleotides in SMA Patient Fibroblasts
Published on: May 11, 2018
Coilin phosphorylation mediates interaction with SMN and SmB'
Cory G Toyota1, Misty D Davis, Angela M Cosman
1Department of Biochemistry, University of Mississippi Medical Center, Jackson, MS 39216, USA.
Chromosoma
|December 10, 2009
Summary
Cajal bodies (CBs) are crucial for spliceosome assembly. Coilin phosphorylation regulates interactions with SMN and Sm proteins, impacting snRNP flow within the CB.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Cajal bodies (CBs) are key nuclear structures involved in spliceosomal small nuclear ribonucleoprotein (snRNP) biogenesis and spliceosome assembly.
- The CB marker protein, coilin, interacts with survival of motor neuron (SMN) and Sm proteins, essential components of snRNPs.
- Coilin phosphorylation sites have been identified, and phosphorylation is known to affect coilin's self-interaction and nuclear localization.
Purpose of the Study:
- To investigate the impact of coilin phosphorylation on its interaction with SMN and Sm proteins.
- To determine if phosphorylation status influences the binding affinity of coilin to SMN and SmB'.
Main Methods:
- In vitro binding assays using C-terminal coilin fragments and phosphomimetic constructs.
- Bacterial expression and purification of full-length coilin.
- Co-immunoprecipitation and phosphatase treatment experiments in vivo.
Main Results:
- SMN protein preferentially binds to dephosphorylated coilin analogs in vitro.
- SmB' protein shows preferential binding to phosphomimetic coilin constructs.
- Full-length coilin binds more SMN and SmB' than its C-terminal fragment, and SMN binds dephosphorylated coilin in vivo.
Conclusions:
- Coilin phosphorylation status significantly modulates its interactions with SMN and Sm proteins.
- These phosphorylation-dependent interactions may play a critical role in regulating the trafficking of snRNPs through Cajal bodies.
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