passages: PMC-2133064-sec-12__text
passages: sec
passages: Results
  The observation that AP-3 is found in both cytosolic and membrane subcellular fractions, and that membrane-associated AP-3 can be extracted with salts (Dell'Angelica et al., 1997a) is consistent with its role as a membrane coat that can be recruited from a cytosolic pool. In addition, the punctate staining of AP-3 by immunofluorescence microscopy, its redistribution to the cytosol by BFA, and the reversibility of the BFA effect (Dell'Angelica et al., 1997a; Simpson et al., 1997) also indicate that AP-3 can cycle between the cytosol and membranes. The sensitivity of AP-3 to BFA in cells suggests that its membrane association may be regulated by ARF1, since BFA inhibits ARF1 guanine nucleotide exchange, and has been shown to prevent ARF1 membrane binding in vitro (Donaldson et al., 1992; Helms and Rothman, 1992; Randazzo et al., 1993).
  
  