Alternative Splicing (AS) Provides an Alternative Mechanism for Regulating GLIS3 Expression and Activity

Area of Science:

• Molecular Biology
• Genetics
• Developmental Biology

Background:

• Krüppel-like transcription factor GLIS3 is crucial for tissue development in mice and humans.
• GLIS3 mutations are linked to polycystic kidney disease, diabetes, and hypothyroidism.

Purpose of the Study:

• To identify and characterize novel GLIS3 mRNA isoforms and their encoded proteins.
• To investigate the functional differences between GLIS3 isoforms.
• To explore the post-translational regulation of GLIS3.

Main Methods:

• RNA sequencing to identify novel transcripts.
• Mass spectrometry to identify protein modifications and interactions.
• Transactivation assays to assess protein function.

Main Results:

• A novel, shorter mouse GLIS3 mRNA isoform lacking exon 3 was identified.
• This shorter isoform is more abundant, stable, and transcriptionally active than the previously known longer isoform.
• Mass spectrometry revealed GLIS3 phosphorylation sites and interactions with co-activator/co-repressor complexes.

Conclusions:

• The shorter GLIS3 isoform may be the predominant functional form.
• Post-translational modifications and interactions regulate GLIS3 activity.
• These findings provide insights into GLIS3's role in development and disease.