Fig. 7. Effect of synprint peptides on CSP action. (A) Current records obtained with transiently expressed N-type calcium channels following co-expression of either the cysteine string domain (left traces) or the J domain (right traces) and a cDNA construct corresponding to the synprint region of the rat N-type calcium channel. Note that synprint blocks the effect of the cysteine string region but not that mediated by the J domain. The experimental conditions were as outlined in Fig. 6. (B) Bar graphs summarizing the effect of synprint on the G protein effect mediated by the cysteine string and J domain regions. The numbers in parentheses indicate the number of experiments; the asterisk indicates statistical significance relative to control conditions. The data obtained with the J domain in the presence of synprint did not differ significantly from those shown in Fig. 6 in the absence of synprint.