Telomeric Repeat Binding Factor 1 (TERF1)

Telomeric repeat-binding factor 1 is a telomere specific protein which is a component of the telomere nucleoprotein complex. This protein is present at telomeres throughout the cell cycle and functions as an inhibitor of telomerase, acting in cis to limit the elongation of individual chromosome ends. The protein structure contains a C-terminal Myb motif, a dimerization domain near its N-terminus and an acidic N-terminus. Two transcripts of this gene are alternatively spliced products. The mouse Trf1 mRNA was shown to be ubiquitously expressed as a single 1.9-kb polyadenylated transcript in mouse somatic tissues. High levels of a 2.1-kb transcript were found in testes. In vitro translation of the mouse cDNA resulted in a 56-kD protein that binds to TTAGGG repeat arrays.