Figure 3

CEBPA activates miR-29b at the pri-miR-29a/b1 locus on chromosome 7q32.3. (A) miR-29b belongs to a family of three members (a, b, c), encoded on two loci on chromosome 1q32.2 and chromosome 7q32.3. Although miR-29b is encoded on both chromosomes, the mature miR-29b sequence encoded from the two loci is identical. (B) In addition to miR-29b, only mature miR-29a is induced after CEBPA restoration, but not mature miR-29c. (C) miR-29 family members are generated from two polymerase II primary transcripts: pri-miR-29a/b1 (GenBank accession number EU154353) and pri-miR-29b2/c (EU154351 and EU154352). These primary transcripts are processed to double stranded precursors (pre-miR-29) and ultimately to the mature single stranded miR-29. Both pri-miR-29s are highly conserved in their putative promoter region and in the pre-miR-29 stem sequences, encoded in the last intron (pre-miR-29a, -b1) on chr.7q32.3 and the last exon (pre-miR-29b2, -c) on chr.1q32.2 respectively. (D) Primer pairs dispersed over the pri-miR-29a/b1 and pri-miR-29b2/c confirmed induction of the pri-miR-29a/b1 locus on chr.7q32.3 (D, left), whereas the pri-miR-29b2/c on chromosome 1.q32.2 is not affected by CEBPA expression (D, right). Results are given as fold expression compared with untreated cells (day 0, ^*P<0.05) and represent three independant experiments.