Er-pm Membrane Contact Sites
Er-pm Membrane Contact Sites - Related Videos
07:55
An Improved Method to Isolate Mitochondrial Contact Sites
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2023
Mitochondrial contact sites are protein complexes that interact with mitochondrial inner and outer membrane proteins. These sites are essential for the communication between the mitochondrial membranes and, thus, between the cytosol and the mitochondrial matrix. Here, we describe a method to identify candidates qualifying for this specific class of proteins.
09:12
Three-dimensional Characterization of Interorganelle Contact Sites in Hepatocytes using Serial Section Electron Microscopy
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Cited by 4 •
2022
A simple and comprehensive protocol to acquire three-dimensional details of membrane contact sites between organelles in hepatocytes from the liver or cells in other tissues.
01:49
Conserved Binding Sites
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2020
Many proteins’ biological role depends on their interactions with their ligands, small molecules that bind to specific locations on the protein known as ligand-binding sites. Ligand-binding sites are often conserved among homologous proteins as these sites are critical for protein function. Binding sites are often located in large pockets, and if their location on a protein’s surface is unknown, it can be predicted using various approaches. The energetic method computationally analyses the...
02:40
Ligand Binding Sites
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2020
Proteins are dynamic macromolecules that carry out a wide variety of essential processes; however, the activities of most proteins depend on their interactions with other molecules or ions, known as ligands. Protein-ligand interactions are quite specific; even though numerous potential ligands surround a cellular protein at any given time, only a particular ligand can bind to that protein. Moreover, a ligand binds only to a dedicated area on the surface of the protein, known as the...
08:27
Visualization and Quantification of Endogenous Intra-Organelle Protein Interactions at ER-Mitochondria Contact Sites by Proximity Ligation Assays
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Cited by 4 •
2023
The need for new approaches to study membrane contact sites (MCSs) has grown due to increasing interest in studying these cellular structures and their components. Here, we present a protocol that integrates previously available microscopy technologies to identify and quantify intra-organelle and inter-organelle protein complexes that reside at MCSs.
FAQs
Their close apposition supports communication between the ER and plasma membrane while keeping the organelles distinct. Tethering proteins help coordinate lipid exchange across this interface, linking contact-site organization to lipid homeostasis. Because membrane composition influences membrane behavior, these sites also contribute to membrane dynamics and cellular responses to environmental cues.
Tethering proteins establish and preserve the narrow separation between the ER and plasma membrane. That positioning is functionally important because it places the two membranes close enough to coordinate lipid exchange while maintaining separate organelles. Changes in tethering could therefore affect both the physical organization of the contact and the processes it supports.
Calcium-store depletion triggers STIM1, an ER calcium sensor, to activate Orai channels in the plasma membrane. This creates a route for calcium entry that responds to the ER’s internal state. The mechanism connects calcium-store status with plasma-membrane activity, helping restore calcium entry required for controlled cellular signaling.
Their functions extend beyond calcium signaling to lipid homeostasis, membrane dynamics, and responses to environmental cues. These activities make the contacts relevant to secretion and metabolism, as well as to specialized functions in immune cells and neurons. Their broad influence reflects the importance of coordinated communication between the ER and plasma membrane.
Examining their molecular organization can clarify how tethering proteins, calcium sensors, and plasma-membrane channels work together. This framework helps connect contact-site structure with calcium regulation, lipid exchange, and membrane behavior. It can also explain how these interfaces contribute to secretion, metabolism, immune-cell activation, and neuronal function.
Defects in proteins that organize or operate these contacts can disrupt calcium signaling, lipid homeostasis, membrane dynamics, or responses to environmental cues. Because these processes support secretion, metabolism, immune-cell activation, and neuronal function, contact-site abnormalities are linked to diverse human diseases and provide a context for investigating their cellular origins.