Cloning and functional analysis of the mouse c-kit promoter

Area of Science:

• Molecular Biology
• Developmental Biology
• Genetics

Background:

• The c-kit protooncogene encodes a tyrosine kinase receptor vital for the development of multiple cell lineages.
• Germ line mutations in c-kit lead to developmental deficiencies, highlighting its essential role.
• Understanding c-kit's tissue-specific expression is critical for deciphering its developmental functions.

Purpose of the Study:

• To identify cis-acting elements that regulate tissue-specific expression of the c-kit gene.
• To clone and characterize a functional mouse c-kit promoter for different cell types.
• To pinpoint regulatory regions within the promoter crucial for c-kit gene transcription.

Main Methods:

• Cloning and characterization of the mouse c-kit promoter.
• Reporter gene assays with 5' deletion constructs.
• Analysis of transcription initiation sites (TIS) in various cell types.
• Bioinformatic analysis of promoter sequences for transcription factor binding sites.

Main Results:

• A major c-kit transcription initiation site (TIS) was identified 58 bp upstream of the translation start codon.
• This TIS is active in mouse mast cells and cerebellum c-kit-positive cells.
• Deletion analysis revealed three short regulatory regions in the 5' flanking region that function in both mouse and human c-kit-positive cell lines.
• The promoter sequence lacks TATA and CCAAT boxes but contains binding sites for Sp1, Ap-2, and ETS-domain proteins.

Conclusions:

• The identified regulatory regions are essential for c-kit's tissue-specific expression.
• These elements likely play a significant role in controlling c-kit gene transcription during development.
• The findings provide insights into the molecular mechanisms governing c-kit gene regulation.