title: Interaction of GRASP, a protein encoded by a novel retinoic acid-induced gene, with members of the cytohesin family of guanine nucleotide exchange factors.
abstract: A novel, retinoic acid-induced gene, GRP1-associated scaffold protein (GRASP), was isolated from P19 embryonal carcinoma cells using a subtractive screening strategy. GRASP was found to be highly expressed in brain and exhibited lower levels of expression in lung, heart, embryo, kidney, and ovary. The predicted amino acid sequence of GRASP is characterized by several putative protein-protein interaction motifs, suggesting that GRASP may be a component of a larger protein complex in the cell. Although GRASP does not harbor a predicted membrane spanning domain(s), the protein was observed to be associated with the plasma membrane of transiently transfected mammalian cells. Yeast two-hybrid screening revealed that GRASP interacted strongly with the General Receptor for Phosphoinositides 1 (GRP1), a brefeldin A-insensitive guanine nucleotide exchange factor for the ADP-ribosylation factor family of proteins. GRASP. GRP1 interactions were also demonstrated in vitro and in mammalian cells in which GRASP was shown to enhance GRP1 association with the plasma membrane. Furthermore, GRASP colocalized with endogenous ADP-ribosylation factors at the plasma membrane in transfected cells, suggesting that GRASP may modulate signaling by this family of small GTPases.
authors.affiliation: Program in Molecular Biology, Laboratory of Molecular Pharmacology, College of Pharmacy, Environmental Health Sciences Center, Department of Microbiology, Oregon State University, Corvallis, Oregon, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Nevrivy
authors.forename: V J
authors.initials: VJ
authors.lastname: Peterson
authors.forename: D
authors.initials: D
authors.lastname: Avram
authors.forename: J E
authors.initials: JE
authors.lastname: Ishmael
authors.forename: S G
authors.initials: SG
authors.lastname: Hansen
authors.forename: P
authors.initials: P
authors.lastname: Dowell
authors.forename: D E
authors.initials: DE
authors.lastname: Hruby
authors.forename: M I
authors.initials: MI
authors.lastname: Dawson
authors.forename: M
authors.initials: M
authors.lastname: Leid
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002457:Cell Extracts; D003001:Cloning, Molecular; D018076:DNA, Complementary; D005786:Gene Expression Regulation / Q000187:drug effects; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D006801:Humans; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D011233:Precipitin Tests; D011485:Protein Binding; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D015398:Signal Transduction; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D002352:Carrier Proteins; D002457:Cell Extracts; D018076:DNA, Complementary; C485827:GRIPAP1 protein, human; D020662:Guanine Nucleotide Exchange Factors; D008565:Membrane Proteins; D018160:Receptors, Cytoplasmic and Nuclear; C040985:phosphatidylinositol receptors; C410230:tamalin protein, human; D014212:Tretinoin