Figure 3

General mechanisms to alter linear protein features by alternative splicing. (a) A widespread mechanism is to skip or include an alternative exon (red box) that encodes a functional unit (indicated by the light bulb). The longer splice form with the alternative exon encodes a protein with this feature, the shorter splice form encodes a protein without this feature. (b) The novel mechanism involves a functional unit that is encoded by two non-consecutive exons (the two parts of the light bulb). In contrast to the mechanism mentioned above, the longer splice form encodes a protein without the functional unit although both parts are present on the protein sequence. The disruption of the unit results in a loss of function. The shorter splice form encodes a protein that puts together both parts of the unit which results in a gain of function (complete light bulb).