A novel fluorescent transcriptional reporter for cell-based microarray assays

Area of Science:

• Biochemistry
• Molecular Biology
• Cell Biology

Background:

• Cell-based microarrays are utilized for various biological assays, often employing fluorescent proteins as reporters.
• Fluorescent reporters offer real-time monitoring in living cells but exhibit lower sensitivity compared to enzymatic reporters.

Purpose of the Study:

• To develop a novel transcriptional reporter assay with enhanced sensitivity for screening gain-of-function mutations.
• To identify gain-of-function mutations in the type-I cGMP-dependent protein kinase (PRKG1).

Main Methods:

• Development of a reporter assay utilizing the alkaline phosphatase enzyme and a fluorescent substrate (ELF-97).
• Application of the assay to screen for gain-of-function mutations in PRKG1 using cell-based microarrays.

Main Results:

• The novel assay demonstrated increased sensitivity compared to traditional fluorescent reporters.
• A constitutively active mutant of PRKG1 was successfully identified.
• The identified mutant involved a specific amino acid substitution (Glutamic acid to Lysine at position 81).

Conclusions:

• The developed alkaline phosphatase-based reporter assay provides a sensitive method for screening protein kinase gain-of-function mutations.
• This assay facilitates the discovery of novel enzyme variants, such as the constitutively active PRKG1 mutant identified.