Genetics and Regulatory Impact of Alternative Polyadenylation in Human B-Lymphoblastoid Cells (original) (raw)
Figure 6
3′ sequence motifs are required for the regulatory response to _trans_-acting factors.
Each row reports characterization of one gene at which short and long 3′ transcript forms were associated with different abundance (see Figure 4). At right, each cartoon shows a schematic of a luciferase reporter (hLuc) cloned upstream of the 3′ untranslated region of the indicated gene that produces two 3′ length forms (flags) and bears an inferred regulatory element as indicated (green box or red star) in the long 3′ form. For a given row, top and bottom reporters differ in the naturally occurring allele borne at the proximal polyadenylation signal (orange text): one reporter (red box) bears the allele encoding robust 3′ processing at the proximal site, and the other reporter (blue box) bears the allele eliminating the canonical polyadenylation signal at the proximal site (red X). In left panels, each color represents protein measurements from reporters with one allele at the proximal polyadenylation site, encoding either robust (red) or minimal (blue) 3′ processing. For each point, the _y_-axis reports protein abundance measurements from two versions of the reporter, one with a wild-type 3′ regulatory element (WT) and the other with an engineered mutant allele (red text at right). In each case, reporters were transfected into HEK293T cells expressing an exogenous copy of an RNA-binding regulator as indicated on the _x_-axis. Error bars represent standard deviations (n = 2). (A) IRF5, (B) DIP2B, (C) NAB1.