Telomere C-strand synthesis initiation

Telomere C-strand synthesis initiation DNA polymerases are not capable of de novo DNA synthesis and require synthesis of a primer, usually by a DNA-dependent RNA polymerase (primase) to begin DNA synthesis. In eukaryotic cells, the primer is synthesized by DNA polymerase alpha:primase. First, the DNA primase portion of this complex synthesizes approximately 6-10 nucleotides of RNA primer and then the DNA polymerase portion synthesizes an additional 20 nucleotides of DNA. There have been reports that TRF1 inhibits this activity at telomeres, though the mechanism and physiological relevance of this inhibition remain to be elucidated.