The sex determination pathway in C. elegans must be tightly controlled in order for proper sexual development to occur.
tra-2 encodes a transmembrane protein that is involved in promoting female sexual fate. Therefore,
tra-2 needs to be down-regulated in order for spermatogenesis to occur and up-regulated for oogenesis to occur. This switch in
tra-2 regulation is in part, governed by a link between nuclear export and translational control. The control over nuclear export of
tra-2 is regulated by various factors, including NXF-2. Most mRNAs are exported by the NXF-1/TAP pathway. However,
tra-2 displays an unusual export mechanism because it appears to be CRM-1 dependent. Specific factors such as REF-1/REF-2 and NXF-2 are thought to associate with the
tra-2 3'UTR to influence the choice of export pathway. When these factors are present,
tra-2 exits the nucleus in a CRM-1 dependent fashion. However, if one of these factors is missing,
tra-2 exits via the more typical NXF-1 route. Here, we focus on NXF-2 and its involvement in
tra-2 export. NXF-2 belongs to the same family of proteins as NXF-1, and it binds specifically to the
tra-2 3'UTR consistent with NXF-2 controlling
tra-2 export. We have isolated a deletion of NXF-2 that displays pleiotropic phenotypes such as feminization, sterility and lethality, suggesting that NXF-2 has other mRNA targets. Currently, we are attempting to identify the precise NXF-2 binding site on
tra-2 so that these other mRNA targets may be identified.