title: ASAP3 is a focal adhesion-associated Arf GAP that functions in cell migration and invasion.
abstract: ASAP3, an Arf GTPase-activating protein previously called DDEFL1 and ACAP4, has been implicated in the pathogenesis of hepatocellular carcinoma. We have examined in vitro and in vivo functions of ASAP3 and compared it to the related Arf GAP ASAP1 that has also been implicated in oncogenesis. ASAP3 was biochemically similar to ASAP1: the pleckstrin homology domain affected function of the catalytic domain by more than 100-fold; catalysis was stimulated by phosphatidylinositol 4,5-bisphosphate; and Arf1, Arf5, and Arf6 were used as substrates in vitro. Like ASAP1, ASAP3 associated with focal adhesions and circular dorsal ruffles. Different than ASAP1, ASAP3 did not localize to invadopodia or podosomes. Cells, derived from a mammary carcinoma and from a glioblastoma, with reduced ASAP3 expression had fewer actin stress fiber, reduced levels of phosphomyosin, and migrated more slowly than control cells. Reducing ASAP3 expression also slowed invasion of mammary carcinoma cells. In contrast, reduction of ASAP1 expression had no effect on migration or invasion. We propose that ASAP3 functions nonredundantly with ASAP1 to control cell movement and may have a role in cancer cell invasion. In comparing ASAP1 and ASAP3, we also found that invadopodia are dispensable for the invasive behavior of cells derived from a mammary carcinoma.
authors.affiliation: Laboratory of Cellular and Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA.
authors.forename: Vi Luan
authors.initials: VL
authors.lastname: Ha
authors.forename: Sanita
authors.initials: S
authors.lastname: Bharti
authors.forename: Hiroki
authors.initials: H
authors.lastname: Inoue
authors.forename: William C
authors.initials: WC
authors.lastname: Vass
authors.forename: Fanny
authors.initials: F
authors.lastname: Campa
authors.forename: Zhongzhen
authors.initials: Z
authors.lastname: Nie
authors.forename: Armand
authors.initials: A
authors.lastname: de Gramont
authors.forename: Yvona
authors.initials: Y
authors.lastname: Ward
authors.forename: Paul A
authors.initials: PA
authors.lastname: Randazzo
mesh_terms: D020823:ADP-Ribosylation Factor 1 / Q000235:genetics / Q000378:metabolism; D000089982:ADP-Ribosylation Factor 6; D020727:ADP-Ribosylation Factors / Q000235:genetics / Q000378:metabolism; D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001798:Blood Proteins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D002465:Cell Movement; D005260:Female; D022001:Focal Adhesions / Q000235:genetics / Q000378:metabolism*; D020690:GTPase-Activating Proteins / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D051379:Mice; D041681:NIH 3T3 Cells; D009361:Neoplasm Invasiveness; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000235:genetics / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid
chemical_list: D000089982:ADP-Ribosylation Factor 6; C117891:ASAP1 protein, human; D048868:Adaptor Proteins, Signal Transducing; C485546:Asap1 protein, mouse; D001798:Blood Proteins; D020690:GTPase-Activating Proteins; D009363:Neoplasm Proteins; D019269:Phosphatidylinositol 4,5-Diphosphate; D010750:Phosphoproteins; C039077:platelet protein P47; C488555:ASAP3 protein, human; D020823:ADP-Ribosylation Factor 1; D020727:ADP-Ribosylation Factors; C116691:ARF5 protein, human; C000715348:ARF6 protein, human; C486477:Arf5 protein, mouse; C000715727:Arf6 protein, mouse