Left splice site

Protein start signal Left splice site Right Protein Poly(A) Poiyadenyl-splice stop addition ation site signal signal site ... 

Figure 37-12. Consensus sequences at splice junctions. The 5 (donor or left) and 3 (acceptor or right) sequences are shown. Also shown is the yeast consensus sequence (UACUAAQ for the branch site. In mammalian cells, this consensus sequence is PyNPyPy-PuAPy, where Py is a pyrimidine, Pu is a purine, and N is any nucleotide. The branch site is located 20-40 nucleotides upstream from the 3 site.

Figure 4 Differential O2 sensitivity of L-type Ca channel aic-subunit splice variants, (a) Schematic representation of the full-length aic-subunit of the L-type Ca channel, showing the four repeating domains, each containing six transmembrane alpha helices. The hatched box at the intracellular C-terminal indicates the only site of splice variation, (b-d) Whole-cell Ca + currents (right panels) evoked in HEK293 cells transiently transfected with aic-subunit splice variants hHT (b), rHT (c), and fHT (d) when stepping from a holding potential of —80 mV to OmV for 100 msec (C = control normoxia, H = hypoxia). In the left-hand panels are shown representative time-series plots for each splice variant before, during, and after perfusion with hypoxic solution horizontal bar indicates duration of exposure to hypoxia. Also shown pictorially in each panel is the length of the splice insert.

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