Targeting of Arf-1 to the early Golgi by membrin, an ER-Golgi SNARE.
Arf and Rab family GTPases regulate membrane traffic in cells, yet little is known about how they are targeted to distinct organelles. To identify sequences in Arf-1 necessary for Golgi targeting, we examined the localization of chimeras between Arf-1 and Arf-6. Here, we identify a 16-amino acid sequence in Arf-1 that specifies Golgi targeting and contains a motif (MXXE) that is important for Arf-1 binding to membrin, an ER-Golgi SNARE protein. The MXXE motif is conserved in all Arfs known to localize to the Golgi and enables Arf-1 to localize to the early Golgi. Arf-1 lacking these 16 aa can still localize to the late Golgi where it displays a more rapid Golgi-cytosol cycle than wild-type Arf-1. These studies suggest that membrin recruits Arf-1 to the early Golgi and reveal distinct kinetic cycles for Arf-1 at early and late Golgi determined by different sets of Arf regulators and effectors.
Honda
Akira
A
Laboratory of Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892, USA.
Al-Awar
Omayma S
OS
Hay
Jesse C
JC
Donaldson
Julie G
JG
D020823:ADP-Ribosylation Factor 1 / Q000235:genetics / Q000378:metabolism*; D000089982:ADP-Ribosylation Factor 6; D020727:ADP-Ribosylation Factors / Q000235:genetics / Q000378:metabolism; D020816:Amino Acid Motifs / Q000502:physiology; D000595:Amino Acid Sequence / Q000502:physiology; D001665:Binding Sites / Q000502:physiology; D003600:Cytosol / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D011485:Protein Binding / Q000502:physiology; D021381:Protein Transport / Q000502:physiology; D050766:Qb-SNARE Proteins; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D050600:SNARE Proteins; D015398:Signal Transduction / Q000502:physiology; D033921:Vesicular Transport Proteins / Q000378:metabolism*
D000089982:ADP-Ribosylation Factor 6; C491344:GOSR2 protein, human; D008565:Membrane Proteins; D050766:Qb-SNARE Proteins; D011993:Recombinant Fusion Proteins; D050600:SNARE Proteins; D033921:Vesicular Transport Proteins; D020823:ADP-Ribosylation Factor 1; D020727:ADP-Ribosylation Factors; C000715348:ARF6 protein, human