HIV_1 p24 recombinant antigen.
- Known as:
- HIV_1 p24 Rec. antigenic.
- Catalog number:
- 00174-V
- Product Quantity:
- 100 µg
- Category:
- -
- Supplier:
- Virogen
- Gene target:
- HIV_1 p24 recombinant antigen.
Related products to: HIV_1 p24 recombinant antigen.
Related articles to: HIV_1 p24 recombinant antigen.
- The P-TEFb transcriptional kinase complex regulates the pause release checkpoint step in transcription by RNA polymerase II (RNAPII). We sought to identify hypoxia-specific interactions that could direct P-TEFb activity to hypoxia-responsive genes. Using a biochemical purification approach, we discovered a hypoxia-specific, chromatin-associated interaction between the P-TEFb subunit cyclin T1 (CCNT1), nuclear localized mitochondrial chaperone Tim8-Tim13 complexes, and the hypoxia-inducible, DNA binding transcription factor BHLHE40. This interaction is confirmed across multiple human cell lines. Tim8-Tim13 complex disruption and BHLHE40 silencing both impair the transcriptional response to acute hypoxia. HIF is not involved in the CCNT1/BHLHE40/Tim8-Tim13 interaction, and neither genetic HIF-1β knockout nor pharmacological HIF-2α inhibition (belzutifan) eliminates BHLHE40 expression. Finally, BHLHE40 depletion compromises the proliferation of 786-O clear cell renal carcinoma cells, which constitutively express HIF-2α and hypoxia-responsive genes. Together, these findings reveal a partially HIF-independent regulatory axis, in which Tim8-Tim13 complexes and BHLHE40 modulate P-TEFb activity in the transcriptional response to hypoxia. - Source: PubMed
Publication date: 2026/05/20
Soliman Shimaa Hassan AbdelAzizDe Fabritiis SimoneIwanaszko MartaLin Lawrence AustinDas MadhurimaGold SarahAndersen Grant DavidChakrabarty Ram PChandel Navdeep SShilatifard Ali - Hexim proteins are key RNA-dependent regulators of eukaryotic transcription through 7SK-dependent sequestration and inactivation of the kinase P-TEFb (Cdk9-CyclinT1/2) in the 7SK RNP. P-TEFb activity drives release of RNA polymerase II from promoter-proximal pausing for eukaryotic and HIV-1 transcription. The molecular mechanism by which 7SK binding overcomes an intrinsic Hexim autoinhibition for subsequent P-TEFb inactivation has remained unresolved. Here, using NMR and biophysical methods we demonstrate that Hexim1 homodimer engages two high-affinity sites on 7SK RNA. This dual-site binding triggers a conformational rearrangement in Hexim1's disordered central region that unmasks the Cdk9-binding site, which is otherwise sequestered within an inter-monomer dimer interface. These findings reveal how Hexim autoinhibition dictates its specificity for 7SK RNA and prevents premature P-TEFb inhibition in the absence of 7SK, thereby providing a mechanistic understanding of Hexim/P-TEFb assembly into the 7SK RNP and further considerations for understanding Hexim-Tat competition during viral transcription. - Source: PubMed
Publication date: 2026/01/15
Yang YuanMurrali Maria GraziaGalvan SabrinaWang YaqiangStephen ChristineAjjampore NehaWang XiaoyuFeigon Juli - Activated immune cells are highly susceptible to human immunodeficiency virus (HIV) infection. Vitamin D (VitD) induces antimicrobial responses and reduces cellular activation. We investigated VitD effects on HIV-1 replication, glucose uptake, and gene regulation using computational and in vitro approaches. CD4 T cells from healthy male donors were treated with VitD and infected with HIV-1. After 72 h, p24 protein was measured to assess viral replication. VitD effects on anti- and pro-HIV genes were analyzed by a Boolean network model based on curated databases and the literature. CCR5 and CXCR4 coreceptor expression, AKT phosphorylation, and glucose uptake were evaluated by flow cytometry, and expression of some model-identified genes was quantified by qPCR. VitD reduced p24 by 53.2% ( = 0.0078). Boolean network modeling predicted that VitD upregulates antiviral, migration, and cell-differentiation related genes, while downregulating genes related to cellular activation, proliferation, glucose metabolism, and HIV replication, notably and . In vitro, VitD reduced AKT phosphorylation by 26.6% ( = 0.0156), transcription of by 22.7% ( = 0.0391), and glucose uptake by 22.8% ( = 0.0039) without affecting classic antiviral genes or coreceptor expression. These findings suggest an anti-HIV effect of VitD, mediated through AKT and glucose metabolism downmodulation, both involved in cell activation and HIV-1 replication. - Source: PubMed
Publication date: 2025/03/18
Loaiza John DGómez Jose FernandoMuñoz-Escudero DanielGonzalez Sandra MEubank Timothy KyleRugeles Maria TRodríguez-Perea Ana LucíaAguilar-Jimenez Wbeimar - Cyclin-dependent kinase 9 (CDK9) plays a pivotal role in promoting oncogenic transcriptional pathways, significantly contributing to the development and progression of cancer. Given the unique biostability of d-amino acid, the development of d-amino acid-containing peptides (DAACPs) is a promising strategy for cancer treatment. Currently, no DAACPs inhibitor targeting CDK9-cyclin T1 have been reported. Here, we reported the identification of a novel, highly potent, selective and stable DAACPs inhibitor (peptide-5) targeting CDK9-cyclin T1 interaction. Peptide-5 showed nanomolar inhibitory effect against CDK9-cyclin T1 (IC = 4.16 ± 0.11 nM). Molecular dynamics (MD) simulation exhibited that peptide-5 stably bound to CDK9. Peptide-5 showed good inhibitory activity against multiple types of prostate cancer cells and demonstrated good biostability in mouse serum. Moreover, peptide-5 suppresses the tumor growth in DU145 cell-derived xenografts nude mice. These data suggest that peptide-5 is a potent antitumor candidate for further research. - Source: PubMed
Publication date: 2025/01/06
Xu ZhenGeng YifeiGuan LixiaNiu Miao-MiaoXu CenYang LiLiang Sudong - Cyclin-dependent kinase 9 (CDK9), a catalytic subunit of the positive transcription elongation factor b (P-TEFb) complex, is a global transcriptional elongation factor associated with cell proliferation. CDK9 activity is regulated by certain histone acetyltransferases, such as p300, GCN5 and P/CAF. However, the impact of males absent on the first (MOF) (also known as KAT8 or MYST1) on CDK9 activity has not been reported. Therefore, the present study aimed to elucidate the regulatory role of MOF on CDK9. We present evidence from systematic biochemical assays and molecular biology approaches arguing that MOF interacts with and acetylates CDK9 at the lysine 35 (i.e. K35) site, and that this acetyl-group can be removed by histone deacetylase HDAC1. Notably, MOF-mediated acetylation of CDK9 at K35 promotes the formation of the P-TEFb complex through stabilizing CDK9 protein and enhancing its association with cyclin T1, which further increases RNA polymerase II serine 2 residues levels and global transcription. Our study reveals for the first time that MOF promotes global transcription by acetylating CDK9, providing a new strategy for exploring the comprehensive mechanism of the MOF-CDK9 axis in cellular processes. - Source: PubMed
Publication date: 2024/09/09
Chen WenqiChu JinmengMiao YujuanJiang WenwenWang FeiZhang NaJin JingjiCai Yong