Identification of a rod domain-truncated isoform of nestin, Nes-SΔ<sub>107–254</sub>, in rat dorsal root ganglia

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.

巢蛋白是一种VI型中间丝（IF）蛋白，主要在神经源性和肌源性干细胞中表达。我们之前在大鼠背根神经节神经元中鉴定出了巢蛋白的第一种异构体Nes - S。在这项研究中，我们报道了一种之前未被鉴定的巢蛋白异构体Nes - SΔ107 - 254，它在成年大鼠背根神经节神经元中低水平表达。29 - kD的Nes - SΔ107 - 254与Nes - S相同，只是在其杆状结构域中缺失了一个额外的区域。Nes - SΔ107 - 254的组装受到影响并形成聚集体。与巢蛋白和Nes - S不同，Nes - SΔ107 - 254不具有细胞保护作用。此外，在表达EGFP - Nes - SΔ107 - 254蛋白的HEK293T细胞中观察到半胱天冬酶 - 3激活增加。综上所述，Nes - SΔ107 - 254是一种巢蛋白的杆状结构域截短异构体，容易形成具有细胞毒性的聚集体。