Figure 2.

Identification of the authentic translation start site in GLUT1CBP mRNA. (A) Diagram of the cDNA constructs used for in vitro transcription and translation. Each indicated cDNA insert in pBSKII was transcribed in vitro with T3 RNA polymerase. (B) In vitro translation of native or mutant GLUT1CBP mRNA. Equivalent amounts of purified mRNA were translated in a rabbit reticulocyte lysate in the presence of ³⁵S-methionine. The crude lysate was resolved by SDS-PAGE, and the gel was dried and exposed to a phosphorimager screen. Lane 1 (left), WT, full-length GLUT1CBP mRNA; lane 2, AUG-AAG, upstream AUG changed to AAG; lane 3, TRUNCATED, upstream AUG absent in GLUT1CBP mRNA; and lane 4, WATER, no mRNA.