Cruising along Microtubule Highways: How Membranes Move through the Secretory Pathway

G.S. Bloom's lab is supported by grants from the National Institutes of Health (NIH) (NS30485), the American Cancer Society (CB-58E), and the Robert A. Welch Foundation (I-1236). L.S.B. Goldstein is an Investigator of the Howard Hughes Medical Institute. His lab is also supported in part by a grant from the NIH (GM35252).

Address all correspondence to George S. Bloom, University of Texas Southwestern Medical Center, Department of Cell Biology and Neuroscience, 5323 Harry Hines Blvd., Dallas, TX 75235. Tel.: (214) 648-7680. Fax: (214) 648-9160. E-mail: [email protected]

2. Approximately 11 min was calculated by the equation for three-dimensional diffusion: t = L²/6D, where t = time, L = length (10 μm), and D = diffusion coefficient (2.5 × 10⁻¹⁰ cm²/s) for ∼200-nm-diam granules in neutrophils (13).

3. Approximately 630,000 years was calculated using the equation for one-dimensional diffusion: t = L²/2D, where t = time, L = length (1 m), and D = diffusion coefficient (2.5 × 10⁻¹⁰ cm²/s) for ∼200-nm-diam granules in neutrophils (13).