Endocytic Activity
Endocytic Activity - Related Videos
08:02
Live-cell Imaging of Endocytic Transport using Functionalized Nanobodies in Cultured Cells
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Cited by 1 •
2025
Endocytic and retrograde transport of proteins from the plasma membrane to the trans-Golgi network is essential to maintaining membrane homeostasis and regulating signaling. Here, we describe a method to image and quantify endocytic transport of transmembrane cargo proteins by live-cell microscopy using derivatized anti-GFP nanobodies in HeLa cells.
11:32
Measuring Plasma Membrane Protein Endocytic Rates by Reversible Biotinylation
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Cited by 23 •
2009
Regulated endocytosis governs the cell surface expression levels of the majority of membrane proteins. Here we utilize reducible, membrane impermeant biotinylation reagents to measure the endocytic rate of the dopamine transporter (DAT), a polytopic membrane protein. The method facilitates a straightforward approach to measuring the endocytic rate of most plasma membrane proteins.
05:13
Density Gradient Ultracentrifugation for Investigating Endocytic Recycling in Mammalian Cells
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Cited by 1 •
2021
This paper aims to present a protocol for preparing recycling endosomes from mammalian cells using sucrose density gradient ultracentrifugation.
09:46
Simultaneous pH Measurement in Endocytic and Cytosolic Compartments in Living Cells using Confocal Microscopy
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Cited by 20 •
2014
Several methods are available for measuring intracellular pH but very few of these allow simultaneous measurement of cytoplasmic and organellar pH. Here, we describe in detail a rapid and accurate methodology to simultaneously measure cytoplasmic and vesicular pH by ratiometric imaging of living cells.
10:42
Determining Cell-surface Expression and Endocytic Rate of Proteins in Primary Astrocyte Cultures Using Biotinylation
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Cited by 6 •
2017
Two biotinylation-based methods, designed for determining the cell-surface expression and endocytic rate of proteins expressed at the plasma membrane, are presented in this report.
FAQs
Cargo selection depends on the plasma membrane bending inward around extracellular materials, membrane components, or signaling molecules. This remodeling concentrates selected material inside a forming vesicle rather than leaving it at the cell surface. The resulting vesicle can then enter endosomal compartments, where its contents follow different routes according to the cell’s regulatory needs.
Clathrin-mediated uptake represents one well-characterized pathway for internalizing material from the plasma membrane. Its importance lies in providing a defined route for studying how membrane regions form vesicles and capture cargo. Comparing this pathway with the broader endocytic process helps researchers examine how cells organize internalization while regulating surface receptors, membrane components, and extracellular materials.
Endosomal compartments act as processing stations that help determine the fate of internalized material. Cargo may be recycled to the cell surface, degraded, or transported to another cellular location. These alternatives allow a cell to combine uptake with membrane turnover and signal regulation, rather than treating internalization as a one-way movement into the cell.
Internalization changes how long receptors and signaling molecules remain available at the plasma membrane, which can alter cellular communication. At the same time, recycling returns selected membrane components while degradation removes others. This coordination helps maintain membrane balance and enables cells to regulate both their external environment and the strength or duration of signaling.
Measurements of endocytic activity can reveal whether cells are internalizing extracellular materials, membrane components, or signaling molecules and how those materials are subsequently handled. Examining uptake together with recycling, degradation, or transport provides information about cellular regulation. Such analysis supports studies of nutrient acquisition, receptor signaling, membrane turnover, and other biological processes.
The process is especially relevant when researchers study how cells acquire nutrients, control receptor signals, renew their membranes, or internalize materials associated with pathogens and drug delivery. These applications connect membrane trafficking to both normal cell function and medically important questions, including how infection, cancer, and neurodegeneration may involve altered cellular internalization.
Abnormal internalization can change the availability of receptors, signaling molecules, and membrane components, potentially disrupting how cells respond to their environment. Studying these changes can help clarify mechanisms associated with infection, cancer, and neurodegeneration. The same framework also supports research on pathogen entry and drug delivery by showing how materials move from the cell surface into internal compartments.