Table 1.

Association of SNAREs with detergent resistant membranes

SNARE	Association with DRMs (%)
Syntaxin 1	0% in P2 from homogenized rat brain (Hering et al. 2003); 0% in pancreatic β cells (Ohara-Imaizumi et al. 2004); 0% and 22% in neuroendocrine cells (Lang et al. 2001; Chamberlain et al. 2001), < 10% in synaptosomes from rat brain (Gil et al. 2005)
Syntaxin 2	0% in mast cells (Pombo et al. 2003); 15% in alveolar epithelial cells (Chintagari et al. 2006)
Syntaxin 3	> 50% in mast cells (Pombo et al. 2003; for epithelial cells see also Lafont et al. 1999)
Syntaxin 4	< 10% in endothelial cell membranes and macrophages (Predescu et al. 2005; Kay et al. 2006); approx. 35% in adipocytes (Chamberlain & Gould, 2002); less than 20% and 50% in mast cells (Puri & Roche, 2006; Pombo et al. 2003)
SNAP-25	0%, 20% and 24% in neuroendocrine cells (Lang et al. 2001; Chamberlain et al. 2001; Salaun et al. 2005b); 20% in synaptosomes from rat brain (Gil et al. 2005)
SNAP-23	< 10% in endothelial cell membranes (Predescu et al. 2005); 31% in alveolar epithelial cells (Chintagari et al. 2006); approx. 50% in macrophages (Kay et al. 2006); 54% in neuroendocrine cells (Salaun et al. 2005b); 50 and 70% in mast cells (Pombo et al. 2003; Puri & Roche, 2006); > 70% in adipocytes (Chamberlain & Gould, 2002)
Synaptobrevin/VAMP2	5–24% in neuroendocrine cells (Chamberlain et al. 2001); < 10% in synaptosomes from rat brain (Gil et al. 2005); approx. 20% in mast cells (Puri & Roche, 2006); 22% in alveolar epithelial cells (Chintagari et al. 2006); 36% in adipocytes (Chamberlain & Gould, 2002); 70–80% in macrophages (Kay et al. 2006)
Cellubrevin/VAMP3	20–30% in macrophages (Kay et al. 2006)

Cell solubilization was performed using Triton X-100 at concentrations ranging from 0.1 to 1%. In the studies by Lang et al. (2001) and Hering et al. (2003) detergent was included in the density gradient steps.