Gpi Transamidase
Gpi Transamidase - Related Videos
01:29
GPI Anchoring of Proteins in the ER Membrane
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2023
GPI-anchoring is a post-translational, reversible protein modification that is ubiquitous in eukaryotes. Such proteins are primarily present on the exoplasmic leaflet of the plasma membrane. GPI-anchor structure A sequence of 11 enzymatic reactions results in the synthesis of the complete GPI anchor consisting of a hydrophobic and a hydrophilic portion. The hydrophobic portion comprises phosphatidylinositol, while the hydrophilic part comprises polar groups like phosphoethanolamine,...
11:55
Preparation of Non-human Primate Brain Tissue for Pre-embedding Immunohistochemistry and Electron Microscopy
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Cited by 6 •
2017
Here, we provide an easy, low-cost, and time-efficient protocol to chemically fix primate brain tissue with acrolein fixative, allowing for long-term preservation that is compatible with pre-embedding immunohistochemistry for transmission electron microscopy.
16:10
A TIRF Microscopy Technique for Real-time, Simultaneous Imaging of the TCR and its Associated Signaling Proteins
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Cited by 13 •
2012
The compartmentalization of proteins either within the plasma membrane or into intracellular locations is one regulatory mechanism that can greatly influence signaling outcomes; hence, to understand signaling it is important to study the spatial and temporal behavior of the proteins involved. We describe here a TIRF microscopy based system to study signal transduction in T cells, but is broadly applicable.
06:46
Non-invasive In Vivo Fluorescence Optical Imaging of Inflammatory MMP Activity Using an Activatable Fluorescent Imaging Agent
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Cited by 4 •
2017
This paper explains the application of fluorescent imaging using an activatable optical imaging probe to visualize the in vivo activity of key matrix metalloproteinases in two different experimental models of inflammation.
08:14
Determining Membrane Protein Topology Using Fluorescence Protease Protection (FPP)
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Cited by 18 •
2015
Here, we present a protocol to determine the orientation and topology of integral membrane proteins in living cells. This simple protocol relies on selective protease sensitivity of chimeras between the protein of interest and GFP.
FAQs
Recognition of the C-terminal GPI-attachment signal determines which proteins enter the anchoring reaction. GPI transamidase cleaves the substrate near its C terminus rather than retaining that terminal segment, creating the protein end needed for transfer. This selectivity helps distinguish proteins destined for GPI anchoring from other proteins handled during cellular protein trafficking.
The anchor-transfer step depends on an already assembled GPI anchor. After cleavage, the protein’s terminal carboxyl group is joined to the amino group of that anchor through an amide bond. This covalent connection converts the processed protein into a membrane-associated form and provides the linkage needed for its display on the extracellular face of the plasma membrane.
The endoplasmic reticulum places GPI transamidase where selected proteins encounter the anchoring machinery during their trafficking through the cell. At this location, signal recognition, C-terminal cleavage, and attachment to a preassembled GPI anchor can occur as connected processing events. Studying this organization helps explain how eukaryotic cells route proteins to the cell surface.
GPI transamidase provides a focused model for examining how protein signals are interpreted and converted into a specific cell-surface destination. Its activity connects a C-terminal attachment signal with covalent membrane anchoring, allowing researchers to relate protein processing in the endoplasmic reticulum to later extracellular localization. This makes the complex relevant to broader studies of eukaryotic trafficking.
The pathway directs selected proteins involved in cell adhesion, signaling, and immune regulation to the extracellular face of the plasma membrane. Their location is biologically important because these functions depend on access to the cell exterior. Consequently, changes affecting GPI anchoring can be studied in relation to how cells communicate, attach, and participate in immune processes.
Research on GPI transamidase supports investigation of congenital GPI-anchor deficiencies, in which disrupted anchoring can affect the delivery of important cell-surface proteins. The pathway is also relevant to parasite biology and to therapeutic strategies aimed at anchor assembly. These applications connect a fundamental trafficking mechanism with disease research, parasite studies, and potential intervention points.