PHAX (phosphorylated adaptor for RNA export) is the key regulator of U snRNA nuclear export in metazoa. Our previous work revealed that PHAX is phosphorylated in the nucleus and is exported as a component of the U snRNA export complex to the cytoplasm, where it is dephosphorylated (M. Ohno, A. Segref, A. Bachi, M. Wilm, and I. W. Mattaj, Cell 101:187-198, 2000). PHAX phosphorylation is essentia...

The intracellular distribution of RNAs depends on interactions of cis-acting nuclear export elements or nuclear retention elements with trans-acting nuclear transport or retention factors. To learn about the relationship between export and retention, we isolated RNAs that are exported from nuclei of Xenopus laevis oocytes even when most RNA export is blocked by an inhibitor of Ran-dependent nuc...

The human immunodeficiency virus type-1 Rev protein induces the nuclear export of intron-containing viral mRNAs that harbor its binding site, the Rev response element (RRE). A leucine-rich region of Rev, the activation domain, is essential for function and has been shown to be a nuclear export signal (NES). Although Rev exports viral RNAs that resemble cellular mRNAs, competition studies perfor...

One of the characteristic features of herpesviruses is that most of their genes are intronless. Thus, their replication relies on the selective nuclear export of intronless viral mRNAs, which have to compete with the nuclear export of bulk spliced cellular mRNAs. Therefore, the regulation of nuclear mRNA export is crucial for the replication and pathogenesis of herpesviruses. Besides the thymid...

Little is known about endoplasmic reticulum (ER) export signals, particularly those of members of the G-protein-coupled receptor family. We investigated the structural motifs involved in membrane export of the human pituitary vasopressin V1b/V3 receptor. A series of V3 receptors carrying deletions and point mutations were expressed in AtT20 corticotroph cells. We analyzed the export of these re...

HIV-1 Rev protein directs nuclear export of pre-mRNAs and mRNAs containing its binding site, the Rev response element (RRE). To define how Rev acts, we used conjugates between bovine serum albumin (BSA) and peptides comprising the Rev activation domain (BSA-R). BSA-R inhibited Rev-mediated nuclear RNA export, whereas a mutant activation domain peptide conjugate did not. BSA-R did not affect the...

Yeast Los1p, the homolog of human exportin-t, mediates nuclear export of tRNA. Using fluorescence in situ hybridization, we could show that the export of some intronless tRNA species is not detectably affected by the disruption of LOS1. To find other factors that facilitate tRNA export, we performed a suppressor screen of a synthetically lethal los1 mutant and identified the essential translati...

The paper investigates the FDI-trade relationship, and tests empirically (in a cross-country EU setting) the key determinants of the export intensity of multinational (MNE) subsidiaries. The central focus is the link between the strategic roles and characteristics of MNE subsidiaries, and their export patterns. Expectations about high export intensities of rationalized manufacturers and product...

The purpose of this paper is to examine the relationship between export barriers and the export performance of Greek firms targeting the Iranian market. Reviewing the literature and using expert opinions, 18 variables were identified. A structured questionnaire was applied to 141 Greek firms and exploratory and confirmatory factor analyses were used to categorize variables in 6 dimensions. Then...