Molecular identification and characterization of Tcmago and TcY14 in Taiwania (Taiwania cryptomerioides).

Mago nashi (Mago) and Y14 proteins are highly conserved among eukaryotes, and not only play important roles in oogenesis, embryogenesis and germ-line determination during animal development, but also participate in mRNA localization and splicing in cell growth. We identified mago (Tcmago) and Y14 (TcY14) homologues derived from expressed sequence tags of Taiwania cryptomerioides Hayata seedlings. Tcmago and TcY14 contain coding regions encoding 149 and 216 amino acids, respectively. Multiple amino acid sequence alignments as well as secondary and tertiary structure all predicted that TcMago and TcY14 possessed similar protein structures to the crystal structures of Drosophila melanogaster and human Mago and Y14 proteins. We demonstrated by yeast two-hybrid analysis and a GST pull-down assay that TcMago and TcY14 interacted in vivo and in vitro, confirming structural predictions of their interaction. TcMago and TcY14 were predominately localized in the nucleus. Whole mount in situ hybridization and immunolocalization showed that Tcmago and TcY14 were both detected in root hairs at the levels of transcription and protein expression. Overexpression of Tcmago in transgenic tobacco plants resulted in longer roots and a more complex root system. TcMago and TcY14 may have cellular functions similar to the Mago and Y14 proteins in animals and may be involved in root development in plants.