Nxt1-flox Mouse

Nxt1, also known as p15 or p15-1, is an NTF2-like export protein crucial for RNA translocation across the nuclear envelope [1,2]. It shuttles between the nucleus and cytoplasm in metazoan cells and is involved in the nuclear export of diverse RNAs, playing a vital role in mRNA export pathways essential for protein production and normal cellular functions [1,5,6]. Genetic models, such as those in primates and murine rodents, are valuable for studying Nxt1 [1].

In Drosophila, a partial loss-of-function allele of Nxt1 leads to reduced viability, sterility, and muscle degeneration, along with abnormal mRNA and circRNA expression [5]. In mammalian cells, Nxt1 is a crucial cofactor in TAP-dependent export of intron-containing RNA, and its binding to Tap enhances the recruitment of the complex to nuclear pore complexes for mRNA export [7,8]. Also, Nxt1 promotes the nuclear export of influenza virus nucleoprotein via a CRM1-dependent pathway, and its knockdown decreases viral replication [3]. In SARS-CoV-2 infection, the virus's Nsp1 targets the NXF1-Nxt1 mRNA export receptor, and inhibition of this export promotes pathogenesis [4].

In conclusion, Nxt1 is essential for RNA nuclear export, affecting various biological processes. Studies using gene-knockout or similar models in different organisms have revealed its roles in muscle integrity, viral replication, and host-pathogen interactions. Understanding Nxt1's functions provides insights into normal biological mechanisms and potential therapeutic targets for viral diseases [1,3,4,5,7,8].