Functional Characterization of Single-Nucleotide Polymorphisms in the Human Undifferentiated Embryonic-Cell Transcription Factor 1 Gene

Abstract

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.

Mitochondrial Aminoacyl-tRNA Synthetase Single-Nucleotide Polymorphisms That Lead to Defects in Refolding but Not Aminoacylation

“…While clinical association with these nsSNPs is still unknown, the software SIFT 38 and Polyphen 39 both predict that S57C might be deleterious to function, while N280S substitution is expected to be tolerated. Several recent reports indicated that multiple mutations, particularly double nsSNP mutants in a single gene, can cause severe disease phenotypes, [40][41][42][43] prompting us to investigate the S57C/N280S double mutant in parallel with the corresponding single mutants. Ser57 and Asn280 map to positions away from the catalytic center and the anticodon binding domain of hmtPheRS, and neither variant showed significant loss in secondary structure or aminoacylation activity in vitro compared to wild type (Fig.…”

Mammalian CDC14 phosphatases control exit from stemness in pluripotent cells

“…UTF1 deficiency is able to promote neuronal differentiation in the P19 embryonal carcinoma cell line (Lin et al , 2012). However, both overexpression (Thummer et al , 2010, 2012) and downregulation (van den Boom et al , 2007; Kooistra et al , 2010) of UTF1 interfere with both proliferation and proper differentiation of ESCs. This represents an important technical limitation to assess the exact contribution of UTF1 in Cdc14 DKO ESCs with rescue experiments, since UTF1 silencing hampers cell differentiation already in control pluripotent cells.…”