CDK13-related disorder, also known as congenital heart defects, dysmorphic facial features and intellectual developmental disorder (CHDFIDD) is associated with mutations in the CDK13 gene encoding transcription-regulating cyclin-dependent kinase 13 (CDK13). Here, we focused on the development of craniofacial structures and analyzed early embryonic stages in CHDFIDD mouse models, with one model comprising a hypomorphic mutation in Cdk13 and exhibiting cleft lip/palate, and another model comprising knockout of Cdk13, featuring a stronger phenotype including midfacial cleft. Cdk13 was found to be physiologically expressed at high levels in the mouse embryonic craniofacial structures, namely in the forebrain, nasal epithelium and maxillary mesenchyme. We also uncovered that Cdk13 deficiency leads to development of hypoplastic branches of the trigeminal nerve including the maxillary branch. Additionally, we detected significant changes in the expression levels of genes involved in neurogenesis (Ache, Dcx, Mef2c, Neurog1, Ntn1, Pou4f1) within the developing palatal shelves. These results, together with changes in the expression pattern of other key face-specific genes (Fgf8, Foxd1, Msx1, Meis2 and Shh) at early stages in Cdk13 mutant embryos, demonstrate a key role of CDK13 in the regulation of craniofacial morphogenesis.

• Klíčová slova
• Axons, CDK13, Craniofacial development, Neurite outgrowth, Orofacial clefts, Trigeminal ganglion,
• MeSH
• cyklin-dependentní kinasy metabolismus   genetika   MeSH
• embryo savčí metabolismus   MeSH
• embryonální vývoj * genetika   MeSH
• fenotyp MeSH
• lebka embryologie   patologie   MeSH
• mentální retardace genetika   MeSH
• modely nemocí na zvířatech * MeSH
• mutace genetika   MeSH
• myši MeSH
• nervus trigeminus embryologie   MeSH
• neurogeneze * genetika   MeSH
• obličej embryologie   abnormality   MeSH
• protein doublecortin MeSH
• rozštěp patra genetika   patologie   embryologie   MeSH
• rozštěp rtu genetika   patologie   embryologie   MeSH
• vývojová regulace genové exprese * MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• cyklin-dependentní kinasy MeSH
• Dcx protein, mouse MeSH Prohlížeč
• protein doublecortin MeSH

RNA splicing, the process of intron removal from pre-mRNA, is essential for the regulation of gene expression. It is controlled by the spliceosome, a megadalton RNA-protein complex that assembles de novo on each pre-mRNA intron through an ordered assembly of intermediate complexes1,2. Spliceosome activation is a major control step that requires substantial protein and RNA rearrangements leading to a catalytically active complex1-5. Splicing factor 3B subunit 1 (SF3B1) protein-a subunit of the U2 small nuclear ribonucleoprotein6-is phosphorylated during spliceosome activation7-10, but the kinase that is responsible has not been identified. Here we show that cyclin-dependent kinase 11 (CDK11) associates with SF3B1 and phosphorylates threonine residues at its N terminus during spliceosome activation. The phosphorylation is important for the association between SF3B1 and U5 and U6 snRNAs in the activated spliceosome, termed the Bact complex, and the phosphorylation can be blocked by OTS964, a potent and selective inhibitor of CDK11. Inhibition of CDK11 prevents spliceosomal transition from the precatalytic complex B to the activated complex Bact and leads to widespread intron retention and accumulation of non-functional spliceosomes on pre-mRNAs and chromatin. We demonstrate a central role of CDK11 in spliceosome assembly and splicing regulation and characterize OTS964 as a highly selective CDK11 inhibitor that suppresses spliceosome activation and splicing.

• MeSH
• aktivace enzymů účinky léků   MeSH
• chinolony farmakologie   MeSH
• chromatin metabolismus   MeSH
• cyklin-dependentní kinasy * antagonisté a inhibitory   metabolismus   MeSH
• fosfoproteiny * chemie   metabolismus   MeSH
• fosforylace MeSH
• malý jaderný ribonukleoprotein U2 * chemie   metabolismus   MeSH
• prekurzory RNA * genetika   metabolismus   MeSH
• sestřih RNA * účinky léků   MeSH
• spliceozomy * účinky léků   metabolismus   MeSH
• threonin metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chinolony MeSH
• chromatin MeSH
• cyklin-dependentní kinasy * MeSH
• fosfoproteiny * MeSH
• malý jaderný ribonukleoprotein U2 * MeSH
• OTS964 MeSH Prohlížeč
• prekurzory RNA * MeSH
• threonin MeSH

The identification of the essential role of cyclin-dependent kinases (CDKs) in the control of cell division has prompted the development of small-molecule CDK inhibitors as anticancer drugs. For many of these compounds, the precise mechanism of action in individual tumor types remains unclear as they simultaneously target different classes of CDKs - enzymes controlling the cell cycle progression as well as CDKs involved in the regulation of transcription. CDK inhibitors are also capable of activating p53 tumor suppressor in tumor cells retaining wild-type p53 gene by modulating MDM2 levels and activity. In the current study, we link, for the first time, CDK activity to the overexpression of the MDM4 (MDMX) oncogene in cancer cells. Small-molecule drugs targeting the CDK9 kinase, dinaciclib, flavopiridol, roscovitine, AT-7519, SNS-032, and DRB, diminished MDM4 levels and activated p53 in A375 melanoma and MCF7 breast carcinoma cells with only a limited effect on MDM2. These results suggest that MDM4, rather than MDM2, could be the primary transcriptional target of pharmacological CDK inhibitors in the p53 pathway. CDK9 inhibitor atuveciclib downregulated MDM4 and enhanced p53 activity induced by nutlin-3a, an inhibitor of p53-MDM2 interaction, and synergized with nutlin-3a in killing A375 melanoma cells. Furthermore, we found that human pluripotent stem cell lines express significant levels of MDM4, which are also maintained by CDK9 activity. In summary, we show that CDK9 activity is essential for the maintenance of high levels of MDM4 in human cells, and drugs targeting CDK9 might restore p53 tumor suppressor function in malignancies overexpressing MDM4.

• MeSH
• cyklin-dependentní kinasa 9 antagonisté a inhibitory   metabolismus   MeSH
• genetická transkripce MeSH
• imidazoly farmakologie   MeSH
• inhibitory proteinkinas farmakologie   MeSH
• lidé MeSH
• melanom genetika   metabolismus   patologie   MeSH
• MFC-7 buňky MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory prsu genetika   metabolismus   patologie   MeSH
• piperaziny farmakologie   MeSH
• pluripotentní kmenové buňky metabolismus   MeSH
• proteiny buněčného cyklu biosyntéza   genetika   metabolismus   MeSH
• protoonkogenní proteiny c-mdm2 biosyntéza   genetika   metabolismus   MeSH
• protoonkogenní proteiny biosyntéza   genetika   metabolismus   MeSH
• roskovitin farmakologie   MeSH
• sulfonamidy farmakologie   MeSH
• synergismus léků MeSH
• transfekce MeSH
• triaziny farmakologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• atuveciclib MeSH Prohlížeč
• CDK9 protein, human MeSH Prohlížeč
• Cdk9 protein, mouse MeSH Prohlížeč
• cyklin-dependentní kinasa 9 MeSH
• imidazoly MeSH
• inhibitory proteinkinas MeSH
• MDM2 protein, human MeSH Prohlížeč
• Mdm2 protein, mouse MeSH Prohlížeč
• MDM4 protein, human MeSH Prohlížeč
• Mdm4 protein, mouse MeSH Prohlížeč
• nutlin 3 MeSH Prohlížeč
• piperaziny MeSH
• proteiny buněčného cyklu MeSH
• protoonkogenní proteiny c-mdm2 MeSH
• protoonkogenní proteiny MeSH
• roskovitin MeSH
• sulfonamidy MeSH
• triaziny MeSH