Vpr is a virion-associated protein of human immunodeficiency virus type 1 (HIV-1) whose function in acquired immune deficiency syndrome (AIDS) has been uncertain. We previously employed yeast as a model to examine the effects of Vpr on basic cellular functions; intracellular Vpr was shown to cause cell-growth arrest and structural defects, and these effects were caused by a region of Vpr containing the sequence HFRIGCRHSRIG. Here we show that peptides containing the H(S/F)RIG amino acid sequence motif cause death when added externally to a variety of yeast including Saccharomyces cerevisiae, Kluyveromyces lactis, Candida glabrata, Candida albicans and Schizosaccharomyces pombe. Such peptides rapidly entered the cell from the time of addition, resulting in cell death. Elevated levels of ions, particularly magnesium and calcium ions, abrogated the cytotoxic effect by preventing the Vpr peptides from entering the cells. Extracellular Vpr found in the serum, or breakdown products of extracellular Vpr, may have similar effects to the Vpr peptides described here and could explain the death of uninfected bystander cells during AIDS.
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http://dx.doi.org/10.1111/j.1365-2958.1996.tb02464.x | DOI Listing |
Biomolecules
December 2024
Department of Biophysics and Cancer Biology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa Street 7, 30-387 Krakow, Poland.
Melanoma cells remain resistant to chemotherapy with cisplatin (CisPt) and doxorubicin (DOX). The abnormal expression of Receptor-Interacting Protein Kinase 4 (RIPK4) in certain melanomas contributes to tumour growth through the NFκB and Wnt/β-catenin signalling pathways, which are known to regulate chemoresistance and recurrence. Despite this, the role of RIPK4 in response to chemotherapeutics in melanoma has not been reported.
View Article and Find Full Text PDFEpigenetics Chromatin
January 2025
Department of Biomedical Sciences, Advanced Medical and Dental Institute, Universiti Sains Malaysia, Kepala Batas, Penang, Malaysia.
Despite significant advances in HIV treatment, a definitive cure remains elusive. The first-in-human clinical trial of Excision BioTherapeutics' CRISPR-based HIV cure, EBT-101, demonstrated safety but failed to prevent viral rebound. These outcomes may result from the interplay of several factors.
View Article and Find Full Text PDFSoft Matter
December 2024
MOE Key Laboratory of Macromolecule Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou, 310058, P. R. China.
The incorporation of reversible sacrificial bonds is an important strategy for enhancing the mechanical properties of elastomers. However, the research on the viscoelasticity of vulcanized rubber with a reversible sacrificial bond network lags seriously. In this paper, the effects of metal coordination bonds on the mechanical properties of butadiene-styrene-vinylpyridine rubber vulcanizates (VPR) were systematically investigated.
View Article and Find Full Text PDFMol Cell
November 2024
Department of Chemical and Systems Biology, Stanford University, Stanford, CA 94305, USA; Department of Developmental Biology, Stanford University, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA 94305, USA; Howard Hughes Medical Institutes, Stanford University, Stanford, CA 94305, USA. Electronic address:
Although critical for tuning the timing and level of transcription, enhancer communication with distal promoters is not well understood. Here, we bypass the need for sequence-specific transcription factors (TFs) and recruit activators directly using a chimeric array of gRNA oligos to target dCas9 fused to the activator VP64-p65-Rta (CARGO-VPR). We show that this approach achieves effective activator recruitment to arbitrary genomic sites, even those inaccessible when targeted with a single guide.
View Article and Find Full Text PDFACS Synth Biol
December 2024
Telethon Institute of Genetics and Medicine, 80078 Naples, Italy.
We introduce a biomolecular circuit for precise control of gene expression in mammalian cells. The circuit leverages the stochiometric interaction between the artificial transcription factor VPR-dCas9 and the anti-CRISPR protein AcrIIA4, enhanced with synthetic coiled-coil domains to boost their interaction, to maintain the expression of a reporter protein constant across diverse experimental conditions, including fluctuations in protein degradation rates and plasmid concentrations, by automatically adjusting its mRNA level. This capability, known as robust perfect adaptation (RPA), is crucial for the stable functioning of biological systems and has wide-ranging implications for biotechnological applications.
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