Overexpression of an ADP-ribosylation Factor-Guanine Nucleotide Exchange Factor, BIG2, Uncouples Brefeldin A-induced Adaptor Protein-1 Coat Dissociation and Membrane Tubulation
| Autor: | Kazuhisa Nakayama, Kazumasa Kawamoto, Chisa Shinotsuka, Yusaku Yoshida, Hiroyuki Takatsu |
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| Rok vydání: | 2002 |
| Předmět: |
ADP ribosylation factor
GTPase Biology environment and public health Biochemistry Coat Protein Complex I Mice symbols.namesake chemistry.chemical_compound Animals Guanine Nucleotide Exchange Factors Humans Adaptor Protein Complex gamma Subunits Molecular Biology Brefeldin A Membrane tubulation Cell Membrane Membrane Proteins Signal transducing adaptor protein Cell Biology COPI Golgi apparatus Cell biology Transcription Factor AP-1 chemistry symbols ADP-Ribosylation Factor 1 Guanine nucleotide exchange factor trans-Golgi Network |
| Zdroj: | Journal of Biological Chemistry. 277:9468-9473 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m112427200 |
| Popis: | BIG2 is a guanine nucleotide exchange factor (GEF) for the ADP-ribosylation factor (ARF) family of small GTPases, which regulate membrane association of COPI and adaptor protein (AP)-1 coat protein complexes. A fungal metabolite, brefeldin A (BFA), inhibits ARF-GEFs and leads to redistribution of coat proteins from membranes to the cytoplasm and membrane tubulation of the Golgi complex and the trans-Golgi network (TGN). To investigate the function of BIG2, we examined the effects of BIG2-overexpression on the BFA-induced redistribution of ARF, coat proteins, and organelle markers. The BIG2 overexpression blocked BFA-induced redistribution from membranes of ARF1 and the AP-1 complex but not that of the COPI complex. These observations indicate that BIG2 is implicated in membrane association of AP-1, but not that of COPI, through activating ARF. Furthermore, not only BIG2 but also ARF1 and AP-1 were found as queues of spherical swellings along the BFA-induced membrane tubules emanating from the TGN. These observations indicate that BFA-induced AP-1 dissociation from TGN membranes and tubulation of TGN membranes are not coupled events and suggest that a BFA target other than ARF-GEFs exists in the cell. |
| Databáze: | OpenAIRE |
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