ATF3 Activating transcription factor 3 (
Atf3) is a known RAG with numerous promoters. Atf3 expression increases after nerve injury and overexpression of a constitutively active form of Atf3 increases the rate of peripheral nerve regeneration. Four Atf3 isoforms were identified in
dorsal root ganglia (DRG) so far. These four isoforms differ in TSS, and one differs in the CDS. However it is unclear which promoters are in use in regenerating DRG neurons.
PTEN Phosphatase and tensin homolog (
Pten) is originally identified as a tumor suppressor gene. Recent studies found that Pten also suppressed axon regeneration in
retinal ganglion cells,
corticospinal tract, and DRG neurons. So far 3 Pten isoforms (Pten, PtenJ1, and Pten J2) have been identified and analyzed. Pten J1 is identical in sequence to the conventional Pten isoform except for a difference in TSS and a small shift in the CDS. Pten J2 has a truncated CDS, an alternative transcription start site and a longer
3' UTR compared to the conventional Pten isoform expressed within neurons. The truncated CDS encodes a protein that lacks a phosphate domain. Also, overexpression of Pten J2 and Pten in primary cortical neurons does not influence axon regeneration. So it's hypothesized that Pten J2 works as regulatory RNA to inhibit the activity of Pten. ==See also==