Leucettines, a Class of Potent Inhibitors of cdc2-Like Kinases and Dual Specificity, Tyrosine Phosphorylation Regulated Kinases Derived from the Marine Sponge Leucettamine B: Modulation of Alternative Pre-RNA Splicing

Abstract

We here report on the synthesis, optimization, and biological characterization of leucettines, a family of kinase inhibitors derived from the marine sponge leucettamine B. Stepwise synthesis of analogues starting from the natural structure, guided by activity testing on eight purified kinases, led to highly potent inhibitors of CLKs and DYRKs, two families of kinases involved in alternative pre-mRNA splicing and Alzheimer's disease/Down syndrome. Leucettine L41 was cocrystallized with CLK3. It interacts with key residues located within the ATP-binding pocket of the kinase. Leucettine L41 inhibits the phosphorylation of serine/arginine-rich proteins (SRp), a family of proteins regulating pre-RNA splicing. Indeed leucettine L41 was demonstrated to modulate alternative pre-mRNA splicing, in a cell-based reporting system. Leucettines should be further explored as pharmacological tools to study and modulate pre-RNA splicing. Leucettines may also be investigated as potential therapeutic drugs in Alzheimer's disease (AD) and in diseases involving abnormal pre-mRNA splicing.

Serine/Arginine-Rich Splicing Factor 3 and Heterogeneous Nuclear Ribonucleoprotein A1 Regulate Alternative RNA Splicing and Gene Expression of Human Papillomavirus 18 through Two Functionally Distinguishable cis Elements

“…Thus, our observations indicate that the manipulation of alternative splicing regulation may be a potential therapeutic target for HPV-related cancer. While a chemical inhibitor that targets splicing factors themselves has not been developed yet, the recent development of kinase inhibitors working upstream of splicing factors, such as CDC2-like kinase (CLK) (77)(78)(79) or SR protein kinase (SRPK) (80)(81)(82) for SR protein phosphorylation, may provide a way to block splicing factor activity. Alternatively, splicing cis elements may also be targeted, given the recent development of modified therapeutic oligonucleotides able to modulate splicing regulation (83)(84)(85)(86).…”

cdc-Like/Dual-Specificity Tyrosine Phosphorylation–Regulated Kinases Inhibitor Leucettine L41 Induces mTOR-Dependent Autophagy: Implication for Alzheimer’s Disease

“…YM201636 (6-amino-N-[3-[4-(4-morpholinyl)pyrido [39,29:4,5]furo[3,2-d]pyrimidin-2-yl]phenyl]-3-pyridinecarboxamide) was purchased from Symansis (Timaru, New Zealand). Olomoucine, roscovitine, S-CR8 [2-(S)-(1-ethyl-2-hydroxyethylamino)-6-(4-(2-pyridyl)benzyl)-9-isopropylpurine], aloïsine, alsterpaullone, leucettines L41, L14, L33, and L38 were synthesized in the laboratory as previously described (Leost et al, 2000;Mettey et al, 2003;Bettayeb et al, 2008;Debdab et al, 2011).…”

“…Recombinant DYRK1A, B, 2, 3, and CLK1, 2, 3, 4 were expressed in Escherichia coli, purified, and assayed with appropriate substrates with 15 mM radiolabeled [g-33 P]ATP in the presence of a range of concentrations of drugs as described previously (Debdab et al, 2011;Tahtouh et al, 2012). IC 50 values were determined from the dose-response curves.…”

“…Given the growing number of examples where splicing is abnormally regulated in human disease (review in Singh and Cooper, 2012), it is no surprise that there is increasing interest in pharmacological inhibitors of SR protein kinases, DYRKs, and CLKs as potential therapeutic drugs (review in Hagiwara, 2005;Smith et al, 2012). In this context we recently described leucettines, a family of low molecular weight inhibitors of DYRKs and CLKs derived from the marine natural product leucettamine B (Debdab et al, 2011;Tahtouh et al, 2012).…”

DYRK1A phoshorylates histone H3 to differentially regulate the binding of HP1 isoforms and antagonize HP1‐mediated transcriptional repression

“…An earlier study showed that DYRK1A modulates megakaryoblastic expansion via phosphorylation of NFAT [33]. To investigate whether DYRK1A also plays a role in the cytokinemia, we tested the effect of the specific DYRK1A inhibitor L41 [34] on the megakaryoblastic cell line CMK. These experiments revealed a dosedependent decrease of IL8 and IL1a expression in the presence of the inhibitor (Fig 5B).…”