ARNO is a guanine nucleotide exchange factor for ADP-ribosylation factor 6. Export

@article{citeulike:4122679, abstract = {ADP-ribosylation factors (ARFs) constitute a family of small monomeric GTPases. ARFs 1 and 3 function in the recruitment of coat proteins to membranes of the Golgi apparatus, whereas ARF6 is localized to the plasma membrane, where it appears to modulate both the assembly of the actin cytoskeleton and endocytosis. Like other GTPases, ARF activation is facilitated by specific guanine nucleotide exchange factors (GEFs). ARNO (ARF nucleotide-binding site opener) is a member of a growing family of ARF-GEFs that share a common, tripartite structure consisting of an N-terminal coiled-coil domain, a central domain with homology to the yeast protein Sec7p, and a C-terminal pleckstrin homology domain. Recently, ARNO and its close homologue cytohesin-1 were found to catalyze in vitro nucleotide exchange on ARF1 and ARF3, respectively, raising the possibility that these GEFs function in the Golgi. However, the actual function of these proteins may be determined in part by their ability to interact with specific ARFs and in part by their subcellular localization. We report here that in vitro ARNO can stimulate nucleotide exchange on both ARF1 and ARF6. Furthermore, based on subcellular fractionation and immunolocalization experiments, we find that ARNO is localized to the plasma membrane in mammalian cells rather than the Golgi. It is therefore likely that ARNO functions in plasma membrane events by modulating the activity of ARF6 in vivo. These findings are consistent with the previous observation that cytohesin-1 regulates the adhesiveness of alphaLbeta2 integrins at the plasma membrane of lymphocytes.}, author = {Frank, S. and Upender, S. and Hansen, S. H. and Casanova, J. E.}, citeulike-article-id = {4122679}, citeulike-linkout-0 = {http://view.ncbi.nlm.nih.gov/pubmed/9417041}, citeulike-linkout-1 = {http://www.hubmed.org/display.cgi?uids=9417041}, day = {2}, issn = {0021-9258}, journal = {The Journal of biological chemistry}, keywords = {arf1, arno, curvature, gef, golgi, interactions, lipids, liposome, mechanism, membrane, protein}, month = {January}, number = {1}, pages = {23--27}, posted-at = {2009-03-03 09:42:45}, priority = {2}, title = {ARNO is a guanine nucleotide exchange factor for ADP-ribosylation factor 6.}, url = {http://view.ncbi.nlm.nih.gov/pubmed/9417041}, volume = {273}, year = {1998} }

TY - JOUR ID - citeulike:4122679 L3 - citeulike-article-id:4122679 N2 - ADP-ribosylation factors (ARFs) constitute a family of small monomeric GTPases. ARFs 1 and 3 function in the recruitment of coat proteins to membranes of the Golgi apparatus, whereas ARF6 is localized to the plasma membrane, where it appears to modulate both the assembly of the actin cytoskeleton and endocytosis. Like other GTPases, ARF activation is facilitated by specific guanine nucleotide exchange factors (GEFs). ARNO (ARF nucleotide-binding site opener) is a member of a growing family of ARF-GEFs that share a common, tripartite structure consisting of an N-terminal coiled-coil domain, a central domain with homology to the yeast protein Sec7p, and a C-terminal pleckstrin homology domain. Recently, ARNO and its close homologue cytohesin-1 were found to catalyze in vitro nucleotide exchange on ARF1 and ARF3, respectively, raising the possibility that these GEFs function in the Golgi. However, the actual function of these proteins may be determined in part by their ability to interact with specific ARFs and in part by their subcellular localization. We report here that in vitro ARNO can stimulate nucleotide exchange on both ARF1 and ARF6. Furthermore, based on subcellular fractionation and immunolocalization experiments, we find that ARNO is localized to the plasma membrane in mammalian cells rather than the Golgi. It is therefore likely that ARNO functions in plasma membrane events by modulating the activity of ARF6 in vivo. These findings are consistent with the previous observation that cytohesin-1 regulates the adhesiveness of alphaLbeta2 integrins at the plasma membrane of lymphocytes. IS - 1 JF - The Journal of biological chemistry SN - 0021-9258 EP - 27 TI - ARNO is a guanine nucleotide exchange factor for ADP-ribosylation factor 6. VL - 273 SP - 23 KW - arf1 KW - arno KW - curvature KW - gef KW - golgi KW - interactions KW - lipids KW - liposome KW - mechanism KW - membrane KW - protein AU - Frank, S AU - Upender, S AU - Hansen, SH AU - Casanova, JE PY - 1998/01/02/ UR - http://view.ncbi.nlm.nih.gov/pubmed/9417041 ER -