FIGURE 6.

Regulation of Glut4 mRNA splicing. Glut4 splicing was analyzed by real-time qPCR using primers that span exon junctions to specifically amplify the alternatively spliced Glut4 splice isoforms. Relative Glut4 transcript levels were compared with correctly spliced Glut4 transcript levels (wt) followed by calculation of the fold-change for each splice isoform relative to the fold-change of wt transcripts. Total RNA was obtained from (A) 3T3-L1 adipocytes treated with control or Zfp407 siRNAs (n = 3 per group). Cryptic represents a Glut4 isoform that utilizes a cryptic splice donor 35 nucleotides into the 3rd exon of Glut4 (gtaggc) that is spliced directly to the 5th exon; B, differentiated 3T3-L1 adipocytes were treated with or without 100 nm insulin for 6 h (n = 6 per group). Data are expressed as mean ± S.E. * indicates p < 0.05; and ## indicates p < 0.0001 relative to the wt transcript.