We are focused on learning what makes up the export machinery of a cell and deciphering how this machinery accomplishes the task of export. Having established that Nup153 plays a critical role in specific types of RNA and protein export (Ullman et al, 1999), we are now defining the functional domains within Nup153 and how each of these contributes to the transport of different cargo. This approach led us to the identification of a novel RNA binding domain within Nup153 (Dimaano et al., 2001, Ball et al., 2004, Ball et al., 2007) and to work aimed at deciphering how this interaction fits into the coordinated events that lead to mRNA transport to the cytoplasm (Ullman, 2002, Dimaano and Ullman, 2004).