Guanosine Tetraphosphate
Guanosine Tetraphosphate - Related Videos
06:04
Thin Layer Chromatography Based Enzyme Activity Assay: A Technique to Determine In Vitro Pyrophosphokinase Activity Using Thin Layer Chromatography
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2025
This video demonstrates a thin-layer chromatography-based enzyme assay to determine pyrophosphokinase activity using radiolabeled nucleotides. The method provides insights into nucleotide synthesis and phosphotransfer reactions.
02:43
Thin-Layer Chromatography-Based Separation of (p)ppGpp Nucleotides Isolated from Stress-Induced Bacteria
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2025
Source: Fernández-Coll, L. and Cashel, M. Using Microtiter Dish Radiolabeling for Multiple In Vivo Measurements Of Escherichia coli (p)ppGpp Followed by Thin Layer Chromatography. J. Vis. Exp. (2019)This video presents a high-throughput protocol for measuring the levels and dynamics of the bacterial stress-response nucleotides ppGpp and pppGpp using thin-layer chromatography (TLC). The method provides a powerful, rapid, and cost-effective approach to quantifying (p)ppGpp in bacterial cultures...
04:38
Differential Radial Capillary Action of Ligand Assay: A High-Throughput Technique to Identify Bacterial Nucleotide Second Messenger-Binding Intracellular Proteins
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2025
This video demonstrates the differential radial capillary action of ligand assay — a technique for systematic high-throughput screening of intracellular nucleotide second messenger-binding proteins. This technique allows for direct binding of the messengers to the overexpressed target protein in the cell lysate — bypassing the need for protein purification.
07:15
Measurement of Cyclic Guanosine Monophosphate (cGMP) in Solid Tissues using Competitive Enzyme-Linked Immunosorbent Assay (ELISA)
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2025
This protocol measures cyclic guanosine monophosphate (cGMP) concentrations in solid tissues using competitive enzyme-linked immunosorbent assay (ELISA). The protocol describes how to process solid tissue, perform competitive ELISA, convert absorbances to cGMP concentrations in picomoles per milliliter, and calculate the final concentrations as nanomoles of cGMP per gram of tissue.
02:14
GTPases and their Regulation
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2020
Guanine nucleotide-binding proteins (G-proteins), also known as GTPases, are a superfamily of proteins that regulate many cellular processes, such as cell signaling, vesicular transport, and the regulation of cell shape and motility. Mutation or dysfunction of these proteins can lead to disease. There are around 40,000 known G-proteins that can broadly be classified into two groups ‒ small G-proteins consisting of a single domain and large multi-domain G-proteins. Large G-proteins, also known...
FAQs
RelA and SpoT link stress sensing to ppGpp production by using guanosine nucleotides and ATP as substrates. Amino acid starvation is a key condition that activates this metabolic signaling route, while other stresses can also engage the stringent response. Examining this enzyme-dependent step helps connect changes in nutrient availability with downstream bacterial behavior.
ppGpp and DksA act with RNA polymerase to redirect transcription rather than merely changing the abundance of a single gene product. This partnership reduces transcription associated with growth and promotes expression of stress-survival pathways. The interaction explains how a bacterial cell can reallocate gene-expression resources when environmental conditions no longer support rapid growth.
The key physiological shift is a change in transcriptional priority: growth-related programs are reduced, while programs associated with surviving stress are activated. This rebalancing connects nutrient limitation with broader bacterial physiology. Consequently, ppGpp signaling is relevant not only to starvation experiments but also to studies of how cells persist under unfavorable conditions.
Chromatography, mass spectrometry, radiolabeling, and transcriptional reporter assays provide complementary ways to study the system. Chromatography, mass spectrometry, and radiolabeling focus on measuring ppGpp, whereas reporter assays examine transcriptional consequences. The choice depends on whether an experiment emphasizes the molecule itself, its production, or the gene-expression response it generates.
Researchers apply these techniques to connect ppGpp measurements with bacterial physiology in experimental contexts involving nutrient limitation and stress adaptation. The same approaches support investigations of antimicrobial tolerance, persistence, and host-microbe interactions. They therefore bridge molecular measurements with bacterial outcomes that matter in infection biology and survival research.
Studies of Guanosine Tetraphosphate are especially relevant when investigators ask why bacteria withstand antimicrobial pressure or remain capable of persistence. Because the pathway redirects transcription toward stress survival, it provides a rationale for examining stress adaptation as a possible antimicrobial target. Such work can also clarify how bacterial responses influence interactions with a host.