Functional characterization of novel human ARFGAP3.
ADP ribosylation factors (ARFs) are critical in the vesicular trafficking pathway. ARF activity is controlled by GTPase-activating proteins (GAPs). We have identified recently a novel tentative ARF GAP derived from human fetal liver, ARFGAP3 (originally named as ARFGAP1). In the present study, we demonstrated that ARFGAP3 had GAP activity in vitro and remarked that the GAP activity of ARFGAP3 was regulated by phospholipids, i.e. phosphatidylinositol 4,5-diphosphate as agonist and phosphatidylcholine as antagonist. ARFGAP3 is a predominantly cytosolic protein, and concentrated in the perinuclear region. Its transient ectopic overexpression in cultured mammalian cells reduced the constitutive secretion of secreted alkaline phosphatase, indicating that ectopic overexpression of ARFGAP3 inhibits the early secretory pathway of proteins in vivo. These results demonstrated that ARFGAP3 is a novel GAP for ARF1 and might be involved in intracellular traffic of proteins and vesicular transport as predicted.
Liu
X
X
Department of Genomics and Proteomics, Beijing Institute of Radiation Medicine, Chinese National Human Genome Center at Beijing, 27 Taiping Road, Beijing 100850, P.R. China.
Zhang
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C
Xing
G
G
Chen
Q
Q
He
F
F
D020727:ADP-Ribosylation Factors; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D015153:Blotting, Western; D019556:COS Cells; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004702:Endocrine Glands / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D020690:GTPase-Activating Proteins / Q000737:chemistry*; D049452:Green Fluorescent Proteins; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D008164:Luminescent Proteins / Q000378:metabolism; D008297:Male; D051379:Mice; D008856:Microscopy, Fluorescence; D010713:Phosphatidylcholines / Q000378:metabolism; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013737:Testis / Q000378:metabolism; D013879:Thioredoxins / Q000378:metabolism; D013997:Time Factors; D014162:Transfection
C503237:ARFGAP1 protein, human; C503240:ARFGAP3 protein, human; C503238:Arfgap1 protein, mouse; C503241:Arfgap3 protein, mouse; D020690:GTPase-Activating Proteins; D008164:Luminescent Proteins; D010713:Phosphatidylcholines; D019269:Phosphatidylinositol 4,5-Diphosphate; D011993:Recombinant Fusion Proteins; D049452:Green Fluorescent Proteins; D013879:Thioredoxins; D006160:Guanosine Triphosphate; D000469:Alkaline Phosphatase; D020727:ADP-Ribosylation Factors