Gst Kinase Pulldown
Gst Kinase Pulldown - Related Videos
11:13
Identification of Kinase-substrate Pairs Using High Throughput Screening
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Cited by 1 •
2015
Protein phosphorylation is a central feature of how cells interpret and respond to information in their extracellular milieu. Here, we present a high throughput screening protocol using kinases purified from mammalian cells to rapidly identify kinases that phosphorylate a substrate(s) of interest.
11:28
Affinity Precipitation of Active Rho-GEFs Using a GST-tagged Mutant Rho Protein (GST-RhoA(G17A)) from Epithelial Cell Lysates
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Cited by 14 •
2012
The method presented here describes an assay to follow activation of RhoA specific GDP/GTP Exchange Factors (GEFs) in cultured cells by making use of a mutant RhoA GST fusion protein that has high affinity for activated GEFs. GEFs are precipitated from cell lysates, detected by Western blotting and quantified by densitometry.
11:22
GST-His purification: A Two-step Affinity Purification Protocol Yielding Full-length Purified Proteins
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Cited by 18 •
2013
In the present protocol, we demonstrate a highly efficient and cost-effective small-scale protein purification method, which allows purification of recombinant proteins by uniquely combining a cleavable GST-tag and a small His-tag.
02:54
Protein Kinases and Phosphatases
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2020
Proteins undergo chemical modifications that trigger changes in the charge, structure, and conformation of the proteins. Phosphorylation, acetylation, glycosylation, nitrosylation, ubiquitination, lipidation, methylation, and proteolysis are various protein modifications that regulate protein activity. Such modifications are usually enzyme-driven. Protein kinases Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
06:09
Assaying the Kinase Activity of LRRK2 in vitro
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Cited by 3 •
2012
Leucine Rich Repeat Kinase 2 is a large multidomain kinase, mutations in which are the most common genetic cause of Parkinson's disease. Analysis of the kinase activity of this protein has proven to be a crucial tool in understanding the biology and dysfunction of this protein. In this paper, in vitro assaying of the kinase activity of LRRK2 and a selection of its mutants is described, providing an experimental system to examine phosphorylation of putative substrates and potential dysfunction...
FAQs
The GST tag provides the capture handle: it binds glutathione on the bead surface, immobilizing the kinase or kinase-binding protein while leaving its interaction regions available to contact proteins in the sample. During washing, loosely associated material is removed, whereas complexes that remain associated with the bait can be recovered for analysis.
Whether the bait is the kinase itself or a kinase-binding protein determines the interaction question. A kinase bait can be used to examine associated substrates, whereas a binding-protein bait can reveal partners connected to kinase signaling. This distinction helps researchers interpret recovered proteins as candidate interaction partners rather than treating every signal as a direct substrate.
Binding specificity is evaluated by comparing which proteins remain associated after the same incubation and washing process. A protein detected with the GST-linked bait but not in an appropriate comparison supports an interaction associated with that bait. Using purified proteins focuses the test on direct binding, while a cell lysate preserves a broader mixture of cellular partners.
A basic workflow begins with the GST fusion, glutathione-coated beads, and either a cell lysate or purified protein mixture. The bait is captured on the beads, incubated with the sample, washed to remove unbound or weakly retained material, and eluted for downstream analysis. Keeping these stages distinct helps connect recovered proteins to the pulldown conditions.
Immunoblotting and mass spectrometry answer different follow-up questions. Immunoblotting tests whether a selected protein is present among the recovered material, whereas mass spectrometry can examine the broader set of proteins isolated with the bait. Choice of readout therefore depends on whether the experiment is testing a suspected partner or surveying interaction candidates.
In biology, the assay is especially useful for connecting biochemical association to signaling pathways. Recovering proteins with a kinase or kinase-binding bait can provide evidence for candidate kinase-substrate relationships or signaling partners, helping researchers study how interaction networks are organized. The result is an experimentally tractable bridge between protein interactions and cellular signaling mechanisms.