Regulation of Retention of FosB Intron 4 by PTB
Figure 1
Comparison of fosB I4 sequence among vertebrates.
(A) The filled boxes at the top represent fosB exons. The horizontal lines between the boxes represent the three constitutively spliced introns that are removed from the pre-mRNA generated from the gene encoding FosB. The regulated fourth intron is located between the bold-faced vertical lines. Shown below the pre-mRNA is the I4 sequence from the mouse fos b gene. The sequence to the left of the first//represents the 5′ I4 transcript; the sequence between the two sets of//represents the middle I4 transcript; the sequence to the right of the second//represents the 3′ I4 transcript. The sequence that is underlined is the PTB binding site. (B) Diagrammatic representation of the consensus splice sites, branch point and pyrimidine tract sequences for vertebrates. The human, rat, mouse and fish fosB I4 splice sites are indicated below. Capital letters represent exonic sequence and lowercase letters represent intronic sequence, n denotes any nucleotide, y for pyrimidines, r for purines and p(y)tract for the polypyrimidine tract, the underlined sequence shows the putative decoy 5′ splice site.