G-protein Subunits
G-protein Subunits - Related Videos
08:55
Characterization of Multi-subunit Protein Complexes of Human MxA Using Non-denaturing Polyacrylamide Gel-electrophoresis
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Cited by 3 •
2016
This article describes a simple and rapid protocol to evaluate the oligomeric state of the dynamin-like GTPase MxA protein from lysates of human cells using a combination of non-denaturing PAGE with western blot analysis.
09:36
Recombinant α- β- and γ-Synucleins Stimulate Protein Phosphatase 2A Catalytic Subunit Activity in Cell Free Assays
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Cited by 7 •
2017
This publication presents a protocol showing how to measure the activity of recombinant protein phosphatase 2A catalytic subunit (PP2Ac) in response to recombinant α-synuclein, β-synuclein, or γ-synuclein proteins using a simple colorimetric assay. We show findings regarding α-synuclein specificity toward PP2Ac in mouse brain.
22:10
Multi-target Parallel Processing Approach for Gene-to-structure Determination of the Influenza Polymerase PB2 Subunit
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Cited by 3 •
2013
Structure-based drug design plays an important role in drug development. Pursuing multiple targets in parallel greatly increases the chance of success for lead discovery. The following article highlights how the Seattle Structural Genomics Center for Infectious Disease utilizes a multi-target approach for gene-to-structure determination of the PB2 influenza A subunit.
06:09
In Vitro Reassociation Assay to Measure the Formation of 80S Ribosomal Particles Using Salt-washed Ribosomal Subunits
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2025
Here, we describe a detailed protocol for the in vitro reassociation of purified, salt-washed eukaryotic ribosomal subunits for the analysis of 80S particle formation. This method is illustrated by analyzing ribosomal subunits isolated from a wild-type strain of Saccharomyces cerevisiae and a mutant strain deficient in the ribosomal protein eL24.
10:01
Combining Chemical Cross-linking and Mass Spectrometry of Intact Protein Complexes to Study the Architecture of Multi-subunit Protein Assemblies
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Cited by 11 •
2017
The architecture of protein complexes is essential for their function. Combining various mass spectrometric techniques proved powerful to study their assembly. We provide protocols for chemical cross-linking and native mass spectrometry and show how these complementary techniques help to elucidate the architecture of multi-subunit protein assemblies.
FAQs
Receptor activation promotes the replacement of GDP with GTP on the alpha subunit. This nucleotide exchange shifts the system from its inactive state into a signaling state, allowing the alpha subunit and the beta-gamma complex to regulate intracellular effectors. The exchange therefore connects receptor stimulation at the cell surface with specific downstream cellular responses.
The alpha subunit and beta-gamma complex act as separate signaling units after receptor activation. The alpha subunit carries the nucleotide-dependent switch, while the beta-gamma complex can also regulate downstream effectors. Considering both components is important because signaling output may reflect coordinated activity from the full heterotrimer rather than alpha-subunit activity alone.
GTP hydrolysis terminates the active signaling phase by converting the alpha subunit back toward its GDP-bound state. This limits the duration of effector regulation and permits reassociation with the beta-gamma complex at the membrane. Without this termination step, receptor-driven signals would not be properly constrained in time.
Activity in this system can influence second-messenger production, ion-channel activity, and broader cellular responses. These outputs provide different readouts of receptor-to-effector communication: second messengers reflect intracellular signal generation, ion channels reflect changes in membrane signaling, and hormone or neurotransmitter responses show how the pathway affects cell behavior.
The alpha, beta, and gamma subunits associate at the inner surface of the membrane in the inactive state. This positioning places the signaling complex near cell-surface receptors and intracellular effectors, helping connect an external stimulus with an internal response. Membrane association is therefore a key spatial feature of efficient cell communication.
These subunits provide a mechanistic link between receptor activation and cellular effects produced by hormones or neurotransmitters. Their control of second messengers and ion channels makes the pathway relevant for studying how signals are transmitted and terminated. Examining this system can therefore help characterize receptor-linked pharmacology and signaling changes associated with disease.