NF-YC complexity is generated by dual promoters and alternative splicing

Area of Science:

• Molecular Biology
• Gene Regulation
• Epigenetics

Background:

• The NF-Y transcription factor, a trimer of NF-YA, NF-YB, and NF-YC subunits, binds the CCAAT box in human promoters.
• NF-YC is a histone-like subunit involved in transcriptional regulation.

Purpose of the Study:

• To characterize novel isoforms of the NF-YC subunit.
• To investigate the cell-dependent regulation and functional impact of NF-YC isoforms on gene transcription and DNA damage response.

Main Methods:

• Analysis of splicing products and isoform abundance.
• Transient transfections and chromatin immunoprecipitations.
• Reverse transcription-PCR to study promoter activity and gene expression.

Main Results:

• Identified at least four NF-YC splicing products, with cell-dependent isoform distribution.
• Demonstrated that specific NF-YA/NF-YC isoform combinations exhibit distinct transcriptional activities.
• Showed differential promoter usage (P1 and P2) affecting NF-YC splicing and response to DNA damage via p53.
• Found that the 37-kDa NF-YC isoform specifically impacts G1/S and apoptosis genes, not G2/M genes.

Conclusions:

• The NF-YC gene exhibits complex transcriptional regulation and alternative splicing, generating diverse NF-Y trimer subtypes.
• Functional diversification of NF-YC subunits contributes to specific roles in gene regulation.
• The 37-kDa NF-YC isoform plays a role in suppressing the DNA damage response under normal growth conditions.