RNA Whole-Mount In situ Hybridisation Proximity Ligation Assay (rISH-PLA), an Assay for Detecting RNA-Protein...

Area of Science:

• Molecular Biology
• Cell Biology
• Biochemistry

Background:

• Studying RNA-protein interactions is challenging due to RNA's complexity.
• Existing methods for detecting RNA-protein complexes often lack spatial resolution and sensitivity.
• There is a need for advanced techniques to analyze RNA regulation in complex cellular environments.

Purpose of the Study:

• To adapt the In Situ Hybridisation-Proximity Ligation Assay (ISH-PLA) for studying RNA regulation.
• To develop a novel method, termed RNA-ISH-PLA (rISH-PLA), for high-resolution detection of RNA-protein complexes.
• To demonstrate the utility of rISH-PLA using a well-characterized RNA-protein interaction in Xenopus oocytes.

Main Methods:

• Modification of the existing ISH-PLA protocol to create the rISH-PLA assay.
• Validation of antibodies against Staufen RNA binding protein (Stau1) using whole-mount immunohistochemistry.
• Validation of Locked Nucleic Acid (LNA) probes for Vg1 mRNA using whole-mount in situ hybridization.
• Application of the combined rISH-PLA assay to detect specific RNA-protein complexes in situ.

Main Results:

• The rISH-PLA assay successfully identified the targeted RNA-protein complex with subcellular and single-cell resolution.
• The method overcomes limitations of conventional techniques, such as lack of spatial resolution and sensitivity in heterogeneous cell populations.
• Independent validation confirmed the specificity of the antibody and LNA probe used in the assay.

Conclusions:

• The developed rISH-PLA technique enables precise identification of RNA-protein complexes at high resolution.
• This method is particularly valuable for studying RNA binding protein (RBP) activity in complex biological samples like tissue sections and whole embryos.
• rISH-PLA offers a significant advancement for research in RNA regulation and molecular interactions within cells.