Related Experiment Video
Updated: Jan 8, 2026

Using the E1A Minigene Tool to Study mRNA Splicing Changes
Published on: April 22, 2021
Mechanism of alternative splicing of yeast HEH1 through competing 5' splice sites
Ankita Katoch Banyal1, Poulami Choudhuri1, Balashankar R Pillai1,2
1Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Mohali, Mohali, India.
Abstract:
Alternative splicing of precursor-messenger RNAs (pre-mRNA) bearing introns with competing 5' splice sites (5'SS) produces two mRNAs. We investigated the mechanism of alternative splicing of the yeast HEH1/SRC1 gene, which contains four nucleotide-apart competing 5'SS, by monitoring its RNA and protein products. HEH1 alternative splicing requires a sixteen-nucleotide pre-mRNA segment spanning its two 5'SS. The nucleotides are decoded by U5 and U6 small nuclear RNAs (snRNAs), supported by specific proteins of the spliceosomal B and Bact complexes, including Prp8. HEH1 alternative splicing became independent of the supporting proteins following recalibration of the pre-mRNA-snRNA base pairings through changes in the 5'SS or U5 and U6 snRNAs. Assisted by proteins that stabilize low-fidelity, high-efficiency spliceosome conformations, the competing HEH1 5'SS are marked for alternative splicing by U5 and U6 snRNAs during the B to Bact transition of the spliceosome.
Related Concept Videos
Alternative RNA Splicing
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...
Alternative RNA Splicing
RNA Splicing
Pre-mRNA Processing: RNA Splicing
Chromatin Structure Regulates pre-mRNA Processing
The chromatin structure, especially...
pre-mRNA Processing
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...

