Figure 4.

The TCE is distinct from the mRNA localization element. (A) Diagram of the constructs used to map the TCE. The SP6 promoter, 5′ UTR (shaded), coding region (hatched), 3′ UTR (black), localization element (LE), poly(A)₂₀ tail (white), and relevant restriction sites are indicated on the Prl-Vg1 construct. Prl, Prl-C2, Prl-C3, and Prl-C8 have deletions from SpeI to EcoRI, BsmI to EcoRI, SpeI to BsmI, and BsmI to NsiI, respectively, as diagrammed. Prl-C7 contains two deletions, from SpeI to BsmI and from NsiI to EcoRI. (B) The relative translational efficiencies of the constructs diagrammed in A were determined (at the RNA concentration of 20 nM) as described in Fig. 1. Values are the average of at least three measurements; standard errors are indicated by the error bars.