Protein Import Assay
Protein Import Assay - Related Videos
10:18
Analysis of Protein Import into Chloroplasts Isolated from Stressed Plants
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Cited by 12 •
2016
Here we describe a new method to study protein import into isolated chloroplasts under stress. The method is rapid and straightforward, and can be applied to study the consequences of different stress conditions for chloroplast protein import, and the corresponding regulatory mechanisms.
01:27
Protein Import into the Peroxisomes
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2023
Cells contain membrane-bound organelles called peroxisomes that oxidize organic molecules by transferring hydrogen atoms to oxygen, producing hydrogen peroxide. Peroxisomes enzymatically convert the released hydrogen peroxide into water and oxygen. Peroxisomal Protein Import: Peroxisomes lack the genetic machinery required to code for their own proteins. Hence, most peroxisomal membrane, lumenal and transmembrane proteins are synthesized in the cytoplasm or ER and transported to the peroxisome...
06:29
Studying Protein Import into Chloroplasts Using Protoplasts
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Cited by 1 •
2018
Here we describe a protocol to express proteins into protoplasts by using PEG-mediated transformation method. The method provides easy expression of proteins of interest, and efficient investigation of protein localization and the import process for various experimental conditions in vivo.
09:01
Measurement of Protein Import Capacity of Skeletal Muscle Mitochondria
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Cited by 2 •
2022
Mitochondria are key metabolic organelles that exhibit a high level of phenotypic plasticity in skeletal muscle. The import of proteins from the cytosol is a critical pathway for organelle biogenesis, essential for the expansion of the reticulum and the maintenance of mitochondrial function. Therefore, protein import serves as a barometer of cellular health.
01:27
ABC Transporters: Importer
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2023
ATP-binding cassette or ABC transporters are a class of ATP-driven pumps that hydrolyze ATP to move solutes across the membrane. They can be grouped into importers and exporters. While exporters are present in all domains of life, importers exist only in bacteria and some plants. In bacteria, based on the number of transmembrane helices and the chemical nature of their substrates, the ABC importers can be divided into three types: Type I imports mostly metabolites such as sugars and amino...
FAQs
Protease protection tests whether the detectable precursor has crossed a membrane barrier rather than merely associated with its surface. After external protease is added, proteins that remain exposed can be degraded, whereas imported material is protected within the organelle or membrane system. Comparing protected and unprotected fractions helps distinguish translocation from nonspecific binding.
ATP availability and membrane potential can reveal energy requirements for transporting a precursor across a membrane. If import changes when either condition is altered, that comparison indicates that the tested process depends on those conditions. Such experiments help separate general precursor binding from energy-dependent translocation and identify requirements for organelle protein delivery.
A change in protein size can indicate that the precursor underwent processing after reaching its destination. Comparing the detectable precursor with its processed form therefore provides evidence about import-associated maturation, rather than relying only on membrane association. This readout can complement protease protection or fractionation when researchers assess whether targeting and compartment entry occurred.
Researchers first combine isolated organelles or a membrane system with a labeled or otherwise detectable precursor protein under selected conditions. After incubation, they assess the material using protease protection, subcellular fractionation, or protein-size changes after processing. Comparing the resulting signals across conditions reveals whether the precursor entered the tested compartment and which requirements influence that outcome.
Subcellular fractionation separates cellular material into fractions that can be examined for the detectable precursor. Its distribution provides an additional way to determine whether the protein is associated with the intended compartment rather than remaining elsewhere in the preparation. Used alongside protection or processing measurements, fractionation strengthens interpretation of compartment-specific delivery.
This approach is useful for studying organelle biogenesis, protein targeting, and transport defects. Researchers can test how targeting sequences, membrane potential, ATP availability, or transport components affect delivery into mitochondria, chloroplasts, or the endoplasmic reticulum. The resulting comparisons connect molecular transport requirements with broader cell-biological processes and disease-related import abnormalities.