Figure 3.

Increasing the distance between the left and right arms of the Alu element results in a shift toward constitutive splicing. (A) Illustration of the Alu element in its antisense orientation. The right and left arms are marked by horizontal brackets. An intronic sequence of 350 bp was inserted in four different positions along the intronic Alu's left arm: (a) between the exonized right arm and the intronic left arm; (b) between the pPPT and the p3′ss of the intronic left arm; (c) in the center of the intronic left arm; (d) downstream of the intronic left arm. (B) Splicing assays were performed as described in Figure 2. Lane 1, splicing products of wild-type ADAR2; lanes 2–5, splicing products of ADAR2 minigene mutated as indicated in A. (C) Intronic sequences of growing lengths (10–300 bp) were inserted between the exonized right arm and the intronic left arm. Lane 1, splicing products of wild-type ADAR2; lanes 2–11, splicing products of ADAR2 minigene mutated as indicated.