Table 2

Diffusion Coefficients and Mobility of CLIMP-63 Constructs

ConstructsDMobilityn
10−10 cm2s−1
wt-GFP1.5 ± 0.4 +5
Δlumen-GFP8.6 ± 3.3 +++6
Δ24–101-GFP3.1 ± 2.1 +12
Δ24–101Δlumen-GFP13.7 ± 2.2 +++4
GFP-Δcytoplasmic8.9 ± 2.4 ++9
GFP-Δcytoplasmic double luminal2.7 ± 1.24
GFP-Δcytoplasmic-Δ511–6017.8 ± 4.2 ++5
GFP-Δcytoplasmic-Δ428–60116.4 ± 8.2 +++4
GFP-Δcytoplasmic-Δ354–60117.8 ± 2.7 +++5
GFP-Δcytoplasmic-Δ218–60117.8 ± 4.9 +++5
GFP-Δcytoplasmic-Δ246–4926.7 ± 2.5 ++8
GFP-Δcytoplasmic-Δ132–35410.8 ± 5.5 +++6
P450 2C2-GFP13.1 ± 6.6 +++6
Sec61β-GFP7.8 ± 1.2 +++6
VSV-G-GFP5.9 ± 1.3 +++5
  • FRAP analysis of GFP fusion constructs reveal strong influence of the luminal segment on diffusion. Deletion of the luminal segment increases diffusion and mobility (Δlumen-GFP) in contrast to deletion of the microtubule binding domain (Δ24–101-GFP), which increases diffusion but not mobility. Note that deletions of the COOH-terminal part have a higher diffusion coefficient. D, diffusion coefficient; n, number of independent experiments. Mobility is measured as a percentage of initial fluorescence: 0–25%, −; 25–50%,+; 50–75%, ++; 75–100%, +++.