Fig. 2. Molecular interactions of the adaptor complex AP-3. The diagram depicts AP-3 subunits. is shown in red, 3 is shown in green, µ3 is shown in brown and 3 is shown in blue. Known interactions with a particular AP-3 subunit are indicated by a solid arrow. Interactions with AP-3 where the subunit is not known are depicted by a dashed arrow. These interactions correspond to PACS-1 (Crump et al., 2001), a casein kinase (Faundez and Kelly, 2000), BLOC-1 (Di Pietro et al., 2006) and inositol phospholipids (PI-Lipids). Vimentin (Styers et al., 2004), clathrin (Dell'Angelica et al., 1998) and the ataxia telangiectasia gene product (ATM) (Lim et al., 1998) directly associate with the 3 subunit. The subunit provides a platform sufficient to bind HIV Gag protein (Dong et al., 2005), protein G of the vesicular stomatitis virus (VSV-G) (Nishimura et al., 2002) or the R-(v)-SNARE VAMP7-TI (Martinez-Arca et al., 2003). Alternatively adaptin in a complex with 3 or 3 by itself binds di-leucine sorting motifs ([DE]xxx[LI]) (Janvier et al., 2003), AGAP1 (Nie et al., 2003), the Arf1 GTPase (Lefrancois et al., 2004), the ear domain (Lefrancois et al., 2004), and the insulin receptor substrate 1 (IRS1) (VanRenterghem et al., 1998). Tyrosine sorting motifs (Yxx) bind to the µ3 subunits (Ohno et al., 1995).