Plant Cell, Vol. 11, 1603-1603, August 1999, Copyright © 1999, American Society of Plant Physiologists
CORRECTION
Bryan C. Gibbon, Laura E. Zonia, David R. Kovar, Patrick J. Hussey, and Christopher J. Staiger (1998). Pollen Profilin Function Depends on Interaction with Proline-Rich Motifs. Plant Cell 10, 981–993.
Errors have been discovered in the methodology used to determine the steady state equilibrium dissociation constant (Kd) for the binding of Zea mays profilin 4 (ZmPRO4) to maize pollen actin, as measured by steady state polymerization of actin and reported on pages 986 (Table 2) and 987 (Figure 5). In the original experiments, too few data points were colinear with the actin control. Additionally, the calcium ion concentration varied by 20% between samples at the upper and lower ends of the curve. These factors resulted in the calculation of inaccurate critical concentration values for ZmPRO4. The conditions used for the assay were refined to include at least four data points for each regression analysis, to keep buffer and calcium conditions identical in each reaction, and to lower the concentration of profilin to 1 µM. These refinements revealed that the Kd for ZmPRO4 binding to pollen actin is significantly lower than that for ZmPRO1 and not somewhat higher, as was originally reported. Corrected versions of Table 2 and Figure 5 are given below. These versions include data obtained for the ZmPRO1-Y6F mutant under polymerizing conditions that were not included in the original versions.
View larger version (19K):
[in this window]
[in a new window]
|
Figure 5.
Analysis of the Binding of Recombinant Maize Profilins to Pollen Actin.
The extent of actin polymerization at steady state was measured by 90° light scattering in the absence of added profilin (square) or in the presence of 1 µM ZmPRO1 (diamond), ZmPRO1-Y6F (triangle), or ZmPRO4 (circle). The Cc (x-intercept) calculated for actin alone was 0.39 µM; in the presence of 1 µM ZmPRO1, ZmPRO1-Y6F, or ZmPRO4, the Cc was 0.68, 0.65, and 0.89 µM, respectively. The Kd values calculated using these Cc values and the equation stated in Methods were 1.0 µM for ZmPRO1, 1.1 µM for ZmPRO1-Y6F, and 0.4 µM for ZmPRO4. AU, arbitrary unit.
|
|
