Position-dependent alternative splicing activity revealed by global profiling of alternative splicing events regulated by PTB.
To gain global insights into the role of the well-known repressive splicing regulator PTB, we analyzed the consequences of PTB knockdown in HeLa cells using high-density oligonucleotide splice-sensitive microarrays. The major class of identified PTB-regulated splicing event was PTB-repressed cassette exons, but there was also a substantial number of PTB-activated splicing events. PTB-repressed and PTB-activated exons showed a distinct arrangement of motifs with pyrimidine-rich motif enrichment within and upstream of repressed exons but downstream of activated exons. The N-terminal half of PTB was sufficient to activate splicing when recruited downstream of a PTB-activated exon. Moreover, insertion of an upstream pyrimidine tract was sufficient to convert a PTB-activated exon to a PTB-repressed exon. Our results show that PTB, an archetypal splicing repressor, has variable splicing activity that predictably depends upon its binding location with respect to target exons.
Llorian
Miriam
M
Department of Biochemistry, University of Cambridge, Cambridge, UK.
Schwartz
Schraga
S
Clark
Tyson A
TA
Hollander
Dror
D
Tan
Lit-Yeen
LY
Spellman
Rachel
R
Gordon
Adele
A
Schweitzer
Anthony C
AC
de la Grange
Pierre
P
Ast
Gil
G
Smith
Christopher W J
CW
D017398:Alternative Splicing; D001483:Base Sequence; D005091:Exons; D006367:HeLa Cells; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D038941:Polypyrimidine Tract-Binding Protein / Q000235:genetics / Q000378:metabolism*; D037941:Silencer Elements, Transcriptional
D038941:Polypyrimidine Tract-Binding Protein