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

Abstract

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.

Keywords: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; ALS; Alternative spliced isoform; Cdk5; DRG; Dorsal root ganglia neuron; GFP; IF; Intermediate filament; MTT; NFH; Nes-S; Nestin; RT-PCR; amyotrophic lateral sclerosis; cyclin-dependent kinase 5; dorsal root ganglia; green fluorescent protein; intermediate filament; neurofilament heavy polypeptide; reverse transcription polymerase chain reaction.