Functional characterization of single-nucleotide polymorphisms in the human undifferentiated embryonic-cell...

Single-nucleotide polymorphisms (SNPs) are single-nucleotide sequence variations between individuals. Two missense SNPs are present in the human undifferentiated embryonic-cell transcription factor 1 (UTF1) gene and their consequences for UTF1 function are investigated in this study. Expression of the UTF1 gene is restricted to pluripotent cells and UTF1 is a chromatin-associated protein with core histone-like properties. UTF1 further acts as a transcriptional repressor and is required for proper differentiation of pluripotent cells. Two missense mutations in UTF1 are reported: rs11599284, which results in a glycine to an arginine change at amino acid 73, and rs4480453, resulting in a leucine to methionine change at amino acid 275. To study the effects of these two SNPs, P19CL6 mouse embryonic carcinoma cells stably expressing eGFP-hUTF1 constructs containing either one or both SNPs were generated. The single and double SNPs did not alter the localization or transcriptional repressor activity of the protein. Further, the single SNPs did not alter the chromatin association and mobility of hUTF1. However, the double mutant, G73R/L275M, demonstrated a decreased chromatin association, indicating a degree of protein malfunction.