Tail-anchored Proteins
Tail-anchored Proteins - Related Videos
01:45
Tail-anchoring of Proteins in the ER Membrane
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2023
Tail-anchored, or TA, proteins are estimated to make up to 3-5% of membrane proteins found in the eukaryotic cell. Such proteins have a single transmembrane domain located approximately 30 amino acid residues upstream from the C-terminal end. As a result, the signal recognition particle (SRP) cannot guide a TA protein to the ER membrane for cotranslational insertion. Hence, they are integrated into the ER membrane post-translationally using their C-terminal end as the anchor. TA proteins...
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,...
01:25
The Anchoring-and-Adjustment Heuristic
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2020
In order to make good decisions, we use our knowledge and our reasoning. Often, this knowledge and reasoning is sound and solid. However, sometimes, we are swayed by biases or by others manipulating a situation. For example, let’s say you and three friends wanted to rent a house and had a combined target budget of $1,600. The realtor shows you only very run-down houses for $1,600 and then shows you a very nice house for $2,000. Might you ask each person to pay more in rent to get the $2,000...
10:17
The Tail Suspension Test
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Cited by 527 •
2012
The tail-suspension test is validated as an experimental procedure to assess antidepressant efficacy of drug treatments in mice. Mice are suspended by their tails for six minutes and escape-related behaviors are assessed. We describe procedures used in conducting the tail suspension test.
15:12
Preparation of Rat Tail Tendons for Biomechanical and Mechanobiological Studies
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Cited by 21 •
2010
This article describes the experimental procedures used to prepare rat tail tendons for biomechanical and mechanobiological studies. Several features of the main steps in preparation are demonstrated, beginning with extraction, cross-sectional area measurement, rinsing and loading into the bioreactor chamber.
FAQs
Recognition occurs after most of the protein has been produced in the cytosol, when the hydrophobic C-terminal segment becomes exposed. Targeting factors identify this tail and help deliver the protein to a membrane insertase. This timing is important because it connects completion of cytosolic synthesis with membrane targeting rather than relying on an N-terminal signal during translation.
The insertion process places the hydrophobic C-terminal segment within the membrane while retaining the larger N-terminal domain on the cytosolic side. This arrangement determines which part of the protein can interact with cytosolic partners and allows the anchored protein to carry out regulatory functions without spanning the membrane with multiple segments.
Membrane insertases provide the machinery that embeds the exposed hydrophobic tail into a cellular membrane. Without this step, the protein would not achieve its membrane-associated configuration. Their activity therefore links targeting-factor recognition to stable membrane localization and helps establish the organization required for functions such as vesicle fusion, apoptosis, and organelle biogenesis.
Their targeting information is positioned at the opposite end of the protein. Instead of using an N-terminal targeting sequence, the completed protein presents a C-terminal hydrophobic segment that targeting factors recognize after cytosolic synthesis. This distinction changes when targeting occurs and explains how these proteins can reach membranes despite lacking an N-terminal signal.
A study of the pathway follows the protein from cytosolic synthesis through exposure of its C-terminal tail, recognition by targeting factors, delivery to a membrane, and insertion by membrane machinery. Examining these stages helps distinguish failures in recognition from defects in membrane embedding and clarifies how targeting controls final cellular localization.
Tail-anchored proteins contribute to vesicle fusion, apoptosis, lipid metabolism, and organelle biogenesis. Their importance extends beyond membrane attachment because incorrect targeting or insertion can disrupt membrane organization and cellular responses to trafficking defects. Studying them therefore connects molecular membrane insertion with broader questions about protein quality control and cellular function.