Recent progress on the structure and function of the TrkH/KtrB ion channel
1Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
Current Opinion in Structural Biology
|July 11, 2014
Summary
The Superfamily of K(+) Transporters (SKT) are ion channels. Recent crystal structures reveal a flexible loop acting as a gate, with nucleotide binding potentially regulating transport mechanisms.
Area of Science:
- Biochemistry
- Structural Biology
- Membrane Transport
Background:
- Superfamily of K(+) Transporters (SKT) are integral membrane proteins.
- SKT proteins are homologous to K(+) channels but their mechanisms were poorly understood.
Purpose of the Study:
- To elucidate the transport and gating mechanisms of SKT proteins.
Main Methods:
- Determination of crystal structures for TrkH and KtrB proteins.
Main Results:
- SKT proteins function as channels with a flexible loop in the permeation pathway acting as a gate.
- Observed conformational changes in gating rings suggest nucleotide-binding regulation.
Conclusions:
- The flexible loop represents a potential gating mechanism in SKT proteins.
- Nucleotide binding likely plays a role in regulating SKT channel activity.
More Related Videos
Related Concept Videos
01:26Voltage-gated Ion Channels
11.2K
Voltage-gated ion channels are transmembrane proteins that open and close in response to changes in the membrane potential. They are present on the membranes of all electrically excitable cells such as neurons, heart, and muscle cells.
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
Generally, all voltage-gated ion channels have a 'voltage-sensing domain' that spans the lipid bilayer. The charged residues in the sensor move in response to the membrane potential changes that open the channel allowing ions movement. There are several types of...
11.2K
01:26Voltage-gated Ion Channels
7.6K
7.6K
01:00Enzyme-linked Receptors
64.5K
Enzyme-linked receptors are proteins that act as both receptor and enzyme, activating multiple intracellular signals. This is a large group of receptors that include the receptor tyrosine kinase (RTK) family. Many growth factors and hormones bind to and activate the RTKs.
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
64.5K
01:12Mechanically-gated Ion Channels
6.6K
Mechanically-gated ion channels are proteins found in eukaryotic and prokaryotic cell membranes that open in response to mechanical stress. Tension, compression, swelling, and shear stress can alter the conformation of the protein, opening a transmembrane channel that allows the passage of ions for signal transmission. In eukaryotes, mechanically-gated channels are distributed in several regions like the neurons, lungs, skin, bladder, and heart, where they play critical roles in numerous...
6.6K
01:12Mechanically-gated Ion Channels
5.8K
5.8K
01:26Receptor Tyrosine Kinases
15.5K
Receptor tyrosine kinases or RTKs are membrane-bound receptors that phosphorylate specific tyrosine on protein substrates. RTKs regulate cellular growth, differentiation, survival, and migration. They contain an extracellular ligand binding domain, a transmembrane domain, and a cytosolic tail with intrinsic kinase activity. Several extracellular signaling molecules activate RTKs in one or more ways and relay the signal downstream. Ligands such as platelet-derived growth factor (PDGF) or...
15.5K