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Hydrogen peroxide regulates splicing by modulating the protein levels of select splice factors
Author(s) -
Sharina Iraida,
Zhu Wen,
Murad Ferid,
Cote Gilbert
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.900.6
Subject(s) - rna splicing , alternative splicing , splice , intron , chemistry , messenger rna , microbiology and biotechnology , exon , in silico , gene isoform , biology , rna , gene , biochemistry
In our previous studies we demonstrated the existence of an alternatively spliced soluble guanylyl cyclase (sGC) isoform C‐α1 resistant to oxidative stress‐induced protein degradation. We extended these studies to address if sGC RNA splicing can be regulated by H 2 O 2 exposure in human breast carcinoma MDA468 cells which constitutively express sGC. RT‐PCR demonstrated that treatment with 1 mM H 2 O 2 for 24h induced the C‐α1 sGC transcript level. To identify potential sGC splicing regulators we performed an in silico analysis using ASD search engine from EMBL. Binding sites for SRp20, hnRNP 2AB1, HuR and PTB1 splice regulators were identified proximal to the regulated and canonical splice acceptors within intron 2. Thus, we investigated if the exposure to H 2 O 2 affects the abundance of these predicted splice regulators. Using Western blotting we observed a significant decrease in levels of PTB1 and hnRNP A2/B1, but not HuR or SRp20 proteins. Next we demonstrated that the expression of PTB1 is affected on the protein, not mRNA level. We also found that oxidative stress‐induced degradation of PTB1 is not mediated by Caspase‐3. These data suggest that H 2 O 2 , a ubiquitous molecule associated with oxidative stress, modulates the expression of a select subset of splicing factors, which might play an important role in cellular stress response and adaptation. Research is supported by the Welch and JS Dunn Foundations to F.M.