Figure 4.
The relationships of ΔRe (solid lines) and ΔIm (dahsed lines) as a function of Gp calculated for intermediate (Cv = 1.2 fF; case I), large (Cv = 4 fF; case II), and small (Cv = 0.5 fF; case III) vesicle size. Note that the change in ΔRe and ΔIm are drawn by a full and an open arrow, respectively. The zero projection on the Re part is reproduced by a change from a fully closed state to a fully open fusion-pore state (see inset) or by a change from a nearly closed state to an incompletely open fusion-pore state (A). The incremental projection in case II is reproduced by a change from nearly closed to incompletely open state (B). The decremental projection in case III can be reproduced, only when the pre-fused state is nearly closed (C). In addition, the change in ΔRe can be considerably larger than the change in ΔIm (see inset). Overlay of ΔRe (Gp) of cases I and III reveals the effect of vesicle size on the projection type (D). By having the same pre-fused state (i.e., the same fusion pore conductance), the incomplete fusion-pore opening of a large vesicle size leads to an incremental projection, whereas, the same incomplete opening of a small vesicle causes a decremental projection in Re.