Subcellular Marker Proteins
Subcellular Marker Proteins - Related Videos
05:04
An Immunolabeling Technique to Visualize the Subcellular Localization of Proteins
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2025
This video demonstrates a technique for the immunolabeling of sigma-1 receptors in a murine heart tissue section using quantum dots. The heart tissue is fixed, osmicated, stained, dehydrated, embedded in resin, and then sectioned. The sections are then treated with antibodies and labeled with quantum dots to demarcate the subcellular localization of Sigma-1 receptors using electron microscopy.
08:23
Intravital Microscopy for Imaging Subcellular Structures in Live Mice Expressing Fluorescent Proteins
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Cited by 18 •
2013
Intravital microscopy is a powerful tool that enables imaging various biological processes in live animals. In this article, we present a detailed method for imaging the dynamics of subcellular structures, such as the secretory granules, in the salivary glands of live mice.
09:20
In situ Subcellular Fractionation of Adherent and Non-adherent Mammalian Cells
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Cited by 29 •
2010
In situ subcellular fractionation of mammalian cells on microscope coverslips allows the visualisation of protein localisation.
04:10
Measuring Proteasome Activity in Different Subcellular Compartments of the Rat Brain
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2025
This video demonstrates how to measure proteasome activity in different subcellular compartments of the lateral amygdala from fear-conditioned and control rat brains using a fluorogenic peptide assay. The proteasome cleaves the fluorogenic peptide substrate, releasing fluorescent molecules, which are quantified using a plate reader to assess proteasome activity in the nuclear and synaptic protein fractions. Increased nuclear activity suggests changes in gene expression, while reduced synaptic...
11:19
Imaging Subcellular Structures in the Living Zebrafish Embryo
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Cited by 8 •
2016
Imaging the dynamic behavior of organelles and other subcellular structures in vivo can shed light on their function in physiological and disease conditions. Here, we present methods for genetically tagging two organelles, centrosomes and mitochondria, and imaging their dynamics in living zebrafish embryos using wide-field and confocal microscopy.
FAQs
Targeting sequences direct proteins toward particular cellular compartments, while retention signals help keep them there after delivery. Membrane interactions provide another means of association, especially for proteins linked to membrane-bound structures. These mechanisms make localization informative: a detected marker can indicate not only where a protein is found, but also which cellular targeting or retention process may be operating.
Enrichment shows that a prepared subcellular fraction contains more of the expected organelle material relative to other cellular components. Researchers also examine markers for compartments that should be absent or less abundant, because their detection can reveal contamination. This comparison helps distinguish a genuinely informative fraction from one whose composition could produce misleading localization or proteomic results.
A marker protein provides a reference point for evaluating the position or composition of a cellular compartment, rather than serving only as an isolated localization observation. Its distribution can be compared across organelles, fractions, or experimental conditions. That comparison supports analysis of cell architecture and can reveal redistribution that would be difficult to interpret without a compartment-specific reference.
Microscopy can detect marker proteins with antibodies or with fluorescent protein fusions. Antibody-based detection identifies the marker through binding, whereas a fluorescent fusion supplies a directly observable signal associated with the tagged protein. Researchers compare the resulting signal with cellular structures or other markers to assess localization and examine spatial changes within cells.
Cells are separated into subcellular fractions, and each fraction is examined for proteins expected to be associated with particular compartments. The distribution of several markers is then compared to assess enrichment and possible contamination. This approach provides biochemical support for compartment assignments and complements imaging by testing whether the expected molecular components partition with a fraction.
They are useful when researchers need to determine whether proteins remain in their usual compartments or redistribute during a cellular response. In trafficking studies, marker patterns help evaluate movement between locations. In disease-related investigations, altered distributions can provide evidence of disrupted organization. The same reference points also strengthen interpretation of microscopy and proteomic analyses.