| First Author | Sun YJ | Year | 2006 |
| Journal | Mol Cell Biol | Volume | 26 |
| Issue | 18 | Pages | 6923-35 |
| PubMed ID | 16943433 | Mgi Jnum | J:112304 |
| Mgi Id | MGI:3656093 | Doi | 10.1128/MCB.02474-05 |
| Citation | Sun YJ, et al. (2006) Solo/Trio8, a membrane-associated short isoform of Trio, modulates endosome dynamics and neurite elongation. Mol Cell Biol 26(18):6923-35 |
| abstractText | With DNA microarrays, we identified a gene, termed Solo, that is downregulated in the cerebellum of Purkinje cell degeneration mutant mice. Solo is a mouse homologue of rat Trio8-one of multiple Trio isoforms recently identified in rat brain. Solo/Trio8 contains N-terminal sec14-like and spectrin-like repeat domains followed by a single guanine nucleotide exchange factor 1 (GEF1) domain, but it lacks the C-terminal GEF2, immunoglobulin-like, and kinase domains that are typical of Trio. Solo/Trio8 is predominantly expressed in Purkinje neurons of the mouse brain, and expression begins following birth and increases during Purkinje neuron maturation. We identified a novel C-terminal membrane-anchoring domain in Solo/Trio8 that is required for enhanced green fluorescent protein-Solo/Trio8 localization to early endosomes (positive for both early-endosome antigen 1 [EEA1] and Rab5) in COS-7 cells and primary cultured neurons. Solo/Trio8 overexpression in COS-7 cells augmented the EEA1-positive early-endosome pool, and this effect was abolished via mutation and inactivation of the GEF domain or deletion of the C-terminal membrane-anchoring domain. Moreover, primary cultured neurons transfected with Solo/Trio8 showed increased neurite elongation that was dependent on these domains. These results suggest that Solo/Trio8 acts as an early-endosome-specific upstream activator of Rho family GTPases for neurite elongation of developing Purkinje neurons. |
