A leading pharmacological strategy toward HIV cure requires "shock" or activation of HIV gene expression in latently infected cells with latency reversal agents (LRAs) followed by their subsequent clearance. In a screen for novel LRAs, we used fungal secondary metabolites as a source of bioactive molecules. Using orthogonal mass spectrometry (MS) coupled to latency reversal bioassays, we identified gliotoxin (GTX) as a novel LRA. GTX significantly induced HIV-1 gene expression in latent ex vivo infected primary cells and in CD4+ T cells from all aviremic HIV-1+ participants. RNA sequencing identified 7SK RNA, the scaffold of the positive transcription elongation factor b (P-TEFb) inhibitory 7SK small nuclear ribonucleoprotein (snRNP) complex, to be significantly reduced upon GTX treatment of CD4+ T cells. GTX directly disrupted 7SK snRNP by targeting La-related protein 7 (LARP7), releasing active P-TEFb, which phosphorylated RNA polymerase II (Pol II) C-terminal domain (CTD), inducing HIV transcription.

• MeSH
• Gliotoxin * metabolism   MeSH
• HeLa Cells MeSH
• HIV Infections * drug therapy   MeSH
• HIV-1 * metabolism   MeSH
• Humans MeSH
• Positive Transcriptional Elongation Factor B genetics   metabolism   MeSH
• RNA-Binding Proteins metabolism   MeSH
• Ribonucleoproteins, Small Nuclear chemistry   MeSH
• Ribonucleoproteins MeSH
• Transcription Factors metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Gliotoxin * MeSH
• Larp7 protein, human MeSH Browser
• Positive Transcriptional Elongation Factor B MeSH
• RNA-Binding Proteins MeSH
• Ribonucleoproteins, Small Nuclear MeSH
• Ribonucleoproteins MeSH
• Transcription Factors MeSH

Congenital heart defects, dysmorphic facial features and intellectual developmental disorders (CHDFIDD) syndrome in humans was recently associated with mutation in CDK13 gene. In order to assess the loss of function of Cdk13 during mouse development, we employed gene trap knock-out (KO) allele in Cdk13 gene. Embryonic lethality of Cdk13-deficient animals was observed by the embryonic day (E) 16.5, while live embryos were observed on E15.5. At this stage, improper development of multiple organs has been documented, partly resembling defects observed in patients with mutated CDK13. In particular, overall developmental delay, incomplete secondary palate formation with variability in severity among Cdk13-deficient animals or complete midline deficiency, kidney failure accompanied by congenital heart defects were detected. Based on further analyses, the lethality at this stage is a result of heart failure most likely due to multiple heart defects followed by insufficient blood circulation resulting in multiple organs dysfunctions. Thus, Cdk13 KO mice might be a very useful model for further studies focused on delineating signaling circuits and molecular mechanisms underlying CHDFIDD caused by mutation in CDK13 gene.

• Keywords
• cyclin, cyclin K, cyclin-dependent kinase (CDK), cyclin-dependent kinase 13, development, mouse, transcription regulation,
• Publication type
• Journal Article MeSH