Nuclear Transport Factor 2 Like Export Factor 2 (NXT2)

Export of mRNAs from the nucleus involves a number of proteins, including nucleoporins, RNA-binding proteins, an RNA helicase (DDX19), and nuclear pore complex-associated proteins, such as NXF1 and RAE1 . By searching EST databases for homologs of p15 (NXT1), Herold et al. (2000) identified cDNAs encoding 2 variants of NXT2, the products of which they termed p15-2a and p15-2b. The variants differ in their 5-prime exons. The deduced 15-2a and 15-2b proteins contain 142 and 114 amino acids, respectively, and are highly homologous to Drosophila and worm proteins, as well as to NXT1. Fluorescence microscopy demonstrated NXT2 expression predominantly in the nucleoplasm and nuclear envelope, with a fraction found in the cytoplasm. Like NXT1, NXT2 was excluded from the nucleolus.