The α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor is an ionotropic transmembrane receptor for glutamate (iGluR) that mediates fast synaptic transmission in the central nervous system (CNS). It has been traditionally classified as a non-NMDA-type receptor, along with the kainate receptor. Its name is derived from its ability to be activated by the artificial glutamate analog AMPA. The receptor was first named the "quisqualate receptor" by Watkins and colleagues after a naturally occurring agonist quisqualate and was only later given the label "AMPA receptor" after the selective agonist developed by Tage Honore and colleagues at the Royal Danish School of Pharmacy in Copenhagen. The GRIA2-encoded AMPA receptor ligand binding core was the first glutamate receptor ion channel domain to be crystallized.
The N-methyl-D-aspartatereceptor (also known as the NMDA receptor or NMDAR), is a glutamate receptor and ion channel found in neurons. The NMDA receptor is one of three types of ionotropic glutamate receptors, the other two being AMPA and kainate receptors. Depending on its subunit composition, its ligands are glutamate and glycine (or D-serine). However, the binding of the ligands is typically not sufficient to open the channel as it may be blocked by Mg2+ ions which are only removed when the neuron is sufficiently depolarized. Thus, the channel acts as a “coincidence detector” and only once both of these conditions are met, the channel opens and it allows positively charged ions (cations) to flow through the cell membrane. The NMDA receptor is thought to be very important for controlling synaptic plasticity and mediating learning and memory functions.
Kainate receptors, or kainic acid receptors (KARs), are ionotropic receptors that respond to the neurotransmitter glutamate. They were first identified as a distinct receptor type through their selective activation by the agonist kainate, a drug first isolated from the algae Digenea simplex. They have been traditionally classified as a non-NMDA-type receptor, along with the AMPA receptor. KARs are less understood than AMPA and NMDA receptors, the other ionotropic glutamate receptors. Postsynaptic kainate receptors are involved in excitatory neurotransmission. Presynaptic kainate receptors have been implicated in inhibitory neurotransmission by modulating release of the inhibitory neurotransmitter GABA through a presynaptic mechanism.
Glutamate receptors are synaptic and non synaptic receptors located primarily on the membranes of neuronal and glial cells. Glutamate is abundant in the human body, but particularly in the nervous system and especially prominent in the human brain where it is the body's most prominent neurotransmitter, the brain's main excitatory neurotransmitter, and also the precursor for GABA, the brain's main inhibitory neurotransmitter. Glutamate receptors are responsible for the glutamate-mediated postsynaptic excitation of neural cells, and are important for neural communication, memory formation, learning, and regulation.
Glutamate receptor 3 is a protein that in humans is encoded by the GRIA3 gene.
Filamin A, alpha (FLNA) is a protein that in humans is encoded by the FLNA gene.
Metabotropic glutamate receptor 7 is a protein that in humans is encoded by the GRM7 gene.
Glutamate [NMDA] receptor subunit zeta-1 is a protein that in humans is encoded by the GRIN1 gene.
Glutamate receptor 1 is a protein that in humans is encoded by the GRIA1 gene.
Glutamate ionotropic receptor AMPA type subunit 2 is a protein that in humans is encoded by the GRIA2 gene and it is a subunit found in the AMPA receptors.
Glutamate ionotropic receptor kainate type subunit 2, also known as ionotropic glutamate receptor 6 or GluR6, is a protein that in humans is encoded by the GRIK2 gene.
Acetylcholine receptor subunit epsilon is a protein that in humans is encoded by the CHRNE gene.
Double-stranded RNA-specific editase 1 is an enzyme that in humans is encoded by the ADARB1 gene. The enzyme is a member of ADAR family.
Glutamate receptor, ionotropic, kainate 1, also known as GRIK1, is a protein that in humans is encoded by the GRIK1 gene.
cAMP-dependent protein kinase catalytic subunit gamma is an enzyme that in humans is encoded by the PRKACG gene.
Neuronal acetylcholine receptor subunit alpha-5, also known as nAChRα5, is a protein that in humans is encoded by the CHRNA5 gene. The protein encoded by this gene is a subunit of certain nicotinic acetylcholine receptors (nAchR).
Glutamate receptor, ionotropic kainate 5 is a protein that in humans is encoded by the GRIK5 gene.
Glutamate receptor delta-1 subunit also known as GluD1 or GluRδ1 is a transmembrane protein encoded by the GRID1 gene. A C-terminal GluD1 splicing isoform has been described based on mRNA analysis.
Within the science of molecular biology and cell biology, for human genetics, the GRIA2 gene is located on chromosome 4q32-q33. The gene product is the ionotropic AMPA glutamate receptor 2. The protein belongs to a family of ligand-activated glutamate receptors that are sensitive to alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA). Glutamate receptors function as the main excitatory neurotransmitter at many synapses in the central nervous system. L-glutamate, an excitatory neurotransmitter, binds to the Gria2 resulting in a conformational change. This leads to the opening of the channel converting the chemical signal to an electrical impulse. AMPA receptors (AMPAR) are composed of four subunits, designated as GluR1 (GRIA1), GluR2 (GRIA2), GluR3 (GRIA3), and GluR4(GRIA4) which combine to form tetramers. They are usually heterotrimeric but can be homodimeric. Each AMPAR has four sites to which an agonist can bind, one for each subunit.[5]
Willardiine (correctly spelled with two successive i's) or (S)-1-(2-amino-2-carboxyethyl)pyrimidine-2,4-dione is a chemical compound that occurs naturally in the seeds of Mariosousa willardiana and Acacia sensu lato. The seedlings of these plants contain enzymes capable of complex chemical substitutions that result in the formation of free amino acids (See: #Synthesis). Willardiine is frequently studied for its function in higher level plants. Additionally, many derivates of willardiine are researched for their potential in pharmaceutical development. Willardiine was first discovered in 1959 by R. Gmelin, when he isolated several free, non-protein amino acids from Acacia willardiana (another name for Mariosousa willardiana) when he was studying how these families of plants synthesize uracilyalanines. A related compound, Isowillardiine, was concurrently isolated by a different group, and it was discovered that the two compounds had different structural and functional properties. Subsequent research on willardiine has focused on the functional significance of different substitutions at the nitrogen group and the development of analogs of willardiine with different pharmacokinetic properties. In general, Willardiine is the one of the first compounds studied in which slight changes to molecular structure result in compounds with significantly different pharmacokinetic properties.
