FIGURE 6.

Rab13 associates with membranes via protein-protein interactions in tissue. A and B, equal protein aliquots of rat brain (A) and rat liver (B) homogenate in HEPES buffer were spun for 30 min at 200,000 × g, and the resulting pellet fraction (P) was resuspended in ice-cold HEPES buffer with or without 1% Triton X-100 (TX100) or NaCO₃ at pH 11.0. After 15 min of incubation, the samples were spun for 30 min at 200,000 × g, and the resulting supernatant (S2) and pellets (P2) were analyzed by Western blotting using the indicated antibodies. C, quantification of the distribution of Rab proteins from extraction experiments as in A. Data are mean ± S.D. (n = 3 for Rab13 and Rab5). D, quantification of the distribution of Rab proteins from extraction experiments as in B. Data are mean ± S.D. (n = 5 for Rab5 and n = 3 Rab13).