A novel mode of action of an ArfGAP, AMAP2/PAG3/Papα, in Arf6 function

被引:33
作者
Hashimoto, S
Hashimoto, A
Yamada, A
Kojima, C
Yamamoto, H
Tsutsumi, T
Higashi, M
Mizoguchi, A
Yagi, R
Sabe, H [1 ]
机构
[1] Osaka Biosci Inst, Dept Mol Biol, Osaka 5650874, Japan
[2] Kyoto Univ, Grad Sch Biostudies, Kyoto 6068502, Japan
[3] Mie Univ, Fac Med, Dept Neural Regenerat & Cell Commun, Tsu, Mie 5148507, Japan
关键词
D O I
10.1074/jbc.M404196200
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Previously we reported that AMAP2/PAG3/Papalpha/ KIAA0400, a GTPase-activating protein ( GAP), acts to antagonize Arf6 function when overexpressed, whereas it was shown to exhibit efficient GAP activities for other Arf isoforms in vitro. Here, we found that AMAP2, through its ArfGAP domain, binds to GTP-Arf6 but not to GDP-Arf6 or other Arfs irrespective of nucleotide status. The majority of AMAP2 was localized to intracellular tubulovesicular structures and redistributed to Arf6-enriched membrane areas upon Arf6 activation. In HeLa cells, Arf6 has been shown to be involved in the clathrin-independent endocytosis of Tac, but not the clathrin-dependent endocytosis of transferrin. We found that Arf6 silencing inhibited the internalization of Tac, but not transferrin, in HeLa cells. Internalization of Tac, but not transferrin, was also significantly inhibited by AMAP2 silencing and overexpression. AMAP2 was moreover found to bind to amphiphysin IIm, a component of the endocytic machinery, via its proline-rich domain. We propose that AMAP2 has dual mechanisms for its function; it exhibits efficient catalytic GAP activity for the class I and II Arfs and yet is involved in the cellular function of the class III Arf without immediate GAP activity. These dual mechanisms of AMAP2 may be important for the cellular function of GTP-Arf6.
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收藏
页码:37677 / 37684
页数:8
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共 53 条
[51]   The Ras target AF-6 interacts with ZO-1 and serves as a peripheral component of tight junctions in epithelial cells [J].
Yamamoto, T ;
Harada, N ;
Kano, K ;
Taya, S ;
Canaani, E ;
Matsuura, Y ;
Mizoguchi, A ;
Ide, C ;
Kaibuchi, K .
JOURNAL OF CELL BIOLOGY, 1997, 139 (03) :785-795
[52]   Phosphoinositide regulation of the actin cytoskeleton [J].
Yin, HL ;
Janmey, PA .
ANNUAL REVIEW OF PHYSIOLOGY, 2003, 65 :761-789
[53]   A requirement for ARF6 in Fcγ receptor-mediated phagocytosis in macrophages [J].
Zhang, Q ;
Cox, D ;
Tseng, CC ;
Donaldson, JG ;
Greenberg, S .
JOURNAL OF BIOLOGICAL CHEMISTRY, 1998, 273 (32) :19977-19981