Autoregulation of the human splice factor kinase CLK1 through exon skipping and intron retention

Uzor, Simon; Zorzou, Panagiota; Bowler, Elisabeth; Porazinski, Sean; Wilson, Ian D; Ladomery, Michaek

Abstract

© 2018 Elsevier B.V. Alternative splicing is a key process required for the regulation of gene expression in normal development and physiology. It is regulated by splice factors whose activities are in turn regulated by splice factor kinases and phosphatases. The CDC-like protein kinases are a widespread family of splice factor kinases involved in normal physiology and in several diseases including cancer. In humans they include the CLK1, CLK2, CLK3 and CLK4 genes. The expression of CLK1 is regulated through alternative splicing producing both full-length catalytically active and truncated catalytically inactive isoforms, CLKT1 (arising from exon 4 skipping) and CLKT2 (arising from intron 4 retention). We examined CLK1 alternative splicing in a range of cancer cell lines, and report widespread and highly variable rates of exon 4 skipping and intron 4 retention. We also examined the effect of severe environmental stress including heat shock, osmotic shock, and exposure to the alkaloid drug harmine on CLK1 alternative splicing in DU145 prostate cancer cells. All treatments rapidly reduced exon 4 skipping and intron 4 retention, shifting the balance towards full-length CLK1 expression. We also found that the inhibition of CLK1 with the benzothiazole TG003 reduced exon 4 skipping and intron 4 retention suggesting an autoregulatory mechanism. CLK1 inhibition with TG003 also resulted in modified alternative splicing of five cancer-associated genes.

• Journal Article Type: Article
• Acceptance Date: May 23, 2018
• Online Publication Date: May 24, 2018
• Publication Date: Sep 5, 2018
• Deposit Date: May 29, 2018
• Publicly Available Date: May 24, 2019
• Journal: Gene
• Print ISSN: 0378-1119
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 670
• Pages: 46-54
• DOI: https://doi.org/10.1016/j.gene.2018.05.095
• Keywords: CDC-like protein kinases, CLK1, alternative splicing, cassette exons, intron retention, detained introns, CLK1 inhibitor TG003, harmine
• Public URL: https://uwe-repository.worktribe.com/output/861071
• Publisher URL: https://doi.org/10.1016/j.gene.2018.05.095
• Additional Information: Additional Information : This is the author's accepted manuscript. The final published version is available here: https://doi.org/10.1016/j.gene.2018.05.095
• Contract Date: May 29, 2018