Telomeric repeat-containing RNA (TERRA)is a long non-coding RNA that forms integral part of telomeric heterochromatin along with the telomeric binding proteins. It plays a key role in maintaining the telomeric structure and plays an important role during the processes like cell differentiation and development. TERRAs are transcribed from the telomeric end of the DNA and almost all the DNA ends have been shown to transcribe the molecule.
Biogenesis of TERRA
TERRA consists of both telomeric and subtelomeric regions. The transcription is initiated in subtelomeric regions and proceeds in the centromere to telomere direction. TERRA is ubiquitously expressed in most all of the tissues by almost all of the mammals studied. TERRA is also expressed in yeasts.
Several studies have shown that TERRA is primarily transcribed by RNA polymerase II, though RNA polymerase I and RNA polymerase III could also play some part in biogenesis.