| First Author | Lévesque L | Year | 2001 |
| Journal | J Biol Chem | Volume | 276 |
| Issue | 48 | Pages | 44953-62 |
| PubMed ID | 11579093 | Mgi Jnum | J:72967 |
| Mgi Id | MGI:2154056 | Doi | 10.1074/jbc.M106558200 |
| Citation | Levesque L, et al. (2001) RNA export mediated by tap involves NXT1-dependent interactions with the nuclear pore complex. J Biol Chem 276(48):44953-62 |
| abstractText | Nuclear export of ribonucleoprotein complexes requires cis-acting signals and recognition by receptors that mediate translocation through the nuclear pore complex. Translocation is likely to involve a series of physical interactions between the ribonucleoprotein complex and nucleoporins within the nuclear pore complex. Here, we have characterized the function of NXT1 in the context of the Tap-dependent RNA export pathway. Tap has been implicated in the nuclear export of RNA transcripts derived from Mason-Pfizer monkey virus that contain the constitutive transport element. We demonstrate that NXT1 stimulates binding of a Tap-RNA complex to nucleoporins in vitro, and we provide mutational analysis that shows these interactions are necessary for nuclear export of an intron-containing viral mRNA in vivo. Tap contains separate domains for binding to nucleoporins and NXT1, both of which are critical for its export function. RNA export is mediated by a heterodimer of Tap and NXT1, and the function of NXT1 on this pathway is to regulate the affinity of the Tap-RNA complex for nucleoporins within the nuclear pore complex. We propose that NXT1-dependent binding of the Tap-RNA complex to the nucleoporin p62, which we have reconstituted in vitro using recombinant proteins, represents a single step of the translocation reaction. |
