Identification of a rod domain-truncated isoform of nestin, Nes-SΔ107-254, in rat dorsal root ganglia

- We previously identified the first nestin isoform, Nes-S, in adult rat DRG neurons.
- We identified Nes-SΔ107-254, the second isoform of nestin, by single neuron RT-PCR.
- Nes-SΔ107-254 is identical to Nes-S, except that half of the rod domain is removed.
- Nes-SΔ107-254 is assembly compromised and does not exert a cytoprotective effect.
- Nes-SΔ107-254 tends to form aggregates that hinder cell survival.

Nestin, a type VI intermediate filament (IF) protein, is predominantly expressed in neurogenic and myogenic stem cells. We previously identified the first isoform of nestin, Nes-S, in rat DRG neurons. In this study, we report a previously unidentified nestin isoform, Nes-SΔ107-254, that is expressed in lower levels in DRG neurons of adult rats. The 29-kD Nes-SΔ107-254 is identical to Nes-S, except that an additional region is removed in its rod domain. Nes-SΔ107-254 is assembly compromised and forms aggregates. Unlike nestin and Nes-S, Nes-SΔ107-254 does not exert cytoprotective effect. Furthermore, elevated caspase-3 activation was observed in HEK293T cells expressing the EGFP-Nes-SΔ107-254 protein. Taken together, Nes-SΔ107-254 is a rod domain-truncated isoform of nestin that is susceptible to form cytotoxic aggregates.