Fig. 10. Fusion protein constructs between GST and the XL-domain of XLαs that allow or prevent translation of ALEX. (A) Structure of the GST–XL cDNA construct, which allows translation of (i) a fusion protein comprising GST linked to amino acid residues 1–321 of the XL-domain of XLαs (ORF1) and (ii) a C-terminally truncated ALEX, ALEX1–310 (ORF2, see also Figure 1B). (B) The GST–XL cDNA construct (top) was mutated to the GST–XL_silORF2 construct (bottom) by altering a nucleotide triplet [TCC (top) to TGA (bottom)] such that the ORF1-encoded protein sequence, which is in-frame with GST, remains unaffected but a stop codon (asterisk) is introduced into ORF2.