The 1.1 - kb 3 ' - UTR of human ET - 1 accounts for over 50 % of the transcript length .
The 1.1 - kb 3 ' - features long tracts of highly conserved sequences including an AU - rich region .
The 1.1 - kb 3 ' - UTR of human ET - 1 accounts for over 50 % of the transcript length and features long tracts of highly conserved sequences including an AU - rich region .