Receptors and Associated Proteins

5-HT or 5-hydroxytryptamines(serotonins) are monoamine neurotransmitters. They originate in neurons deep in the midline of the brainstem. Because these neurons profile diffusely throughout the brain, serotonin can affect various brain functions. It also interacts with many other neurotransmitters, either directly through neurons that use both serotonin and another neurotransmitter, or by serotonin neurons influencing neurons that primarily use these other transmitters. They are involved in the regulation of mood and appetite and play a role is a variety of other functions in the CNS and PNS.

In vertebrates, GABA acts at inhibitory synapses in the brain by binding to specific transmembrane receptors in the plasma membrane of both pre- and postsynaptic neuronal processes. This binding causes the opening of ion channels to allow the flow of either negatively charged chloride ions into the cell or positively charged potassium ions out of the cell. This action results in a negative change in the transmembrane potential, usually causing hyperpolarization. Two general classes of GABA receptor are known: GABAA in which the receptor is part of a ligand-gated ion channel complex, and GABAB metabotropic receptors, which are G protein-coupled receptors that open or close ion channels via intermediaries (G proteins).

The amino-acid glutamate is the primary excitatory transmitter in the mammalian CNS. Fast excitatory actions of glutamate are mediated by ionotropic glutamate receptor (iGluR) N-methyl-D-aspartates (NMDAs), alpha-amino-3-hydroxi-5-methyl-ioxyzole-4-propionic acid, and kainate receptors.  

Leptin is produced by adipose tissue and interacts with six types of receptor (LepRa–LepRf).

The metabotropic glutamate receptors (mGluRs) are G-protein coupled receptors that bind with glutamate to activate neurotransmission. The are expressed in neurons, glia and astrocytes.

They are involved in learning, memory, anxiety, and the perception of pain. mGluRs are found in synapses of the hippocampus, cerebellum, and the cerebral cortex, as well as other parts of the brain and in peripheral tissues.

G-protein coupled receptors (GPCRs) comprises a large and diverse group of membrane receptors for eukaryotes. This diverse cell surface receptor family play a role in a wide range of functions. 

The amino-acid glutamate is the primary excitatory transmitter in the mammalian CNS. Fast excitatory actions of glutamate are mediated by ionotropic glutamate receptor (iGluRs) N-methyl-D-aspartates (NMDAs), alpha-amino-3-hydroxi-5-methyl-ioxyzole-4-propionic acids, and kainate receptors. Metabotropic glutamate receptors (mGluRs) mediate slower glutamate responses through G-protein coupling to various intracellular signaling cascades that can modulate, or fine-tune, iGluR function.

Neuropeptides are neuronal signaling molecules, influence the activity of the brain in specific ways and are thus involved in particular brain functions, like analgesia, reward, food intake, learning and memory.

Neurotensin is a 13-amino acid neuropeptide involved in neurotransmission in the CNS and PNS. The neurotensin receptors (NTS or NTSRs) are transmembrane receptors that bind neurotensin. NTSR1 and NTSR2 contain seven transmembrane helices and are G protein coupled whereas NTSR3 has a single transmembrane domain.

By selective targeting or blockade of specific neurotensin receptors, investigators have identified potential drugs for use in the treatment of schizophrenia, alcoholism, chronic pain, or cancer.

Opioid Receptors are found throughout the central and peripheral nervous systems; and are often important targets in pain and addiction research. 

Extracellular ATP interacts with specific ionotropic (P2X) or metabotropic (P2Y) membrane receptors having different molecular characteristics. Discrete cell-specific expression of various subtypes of ATP receptors allows specificity and selectivity of purinergic responses in many body organs. At single cell level, the ATP effects are susceptible to modulation by crosstalk with other receptors and by intracellular molecular pathways, allowing refinement and plasticity of cell responses. ATP and related nucleotides are now recognized key players in many tissue and cell responses during physiological states or disease conditions, like in chronic pain, inflammation, neurologic disorders and cancer. By Elsa Fabbretti, University of Nova Gorica and user of these antibodies. 

Semaphorins family of cell signaling molecules have functions many different areas such as neuronal development, immunological disease, vascular development and bone disorders. Plexins serve as signal partners for some classes of semaphorins. 

Toll like receptors (TLR) are highly conserved throughout evolution and have been implicated in the innate defense to many pathogens. In mammals, TLR identified as type I transmembrane signaling receptors with pattern recognition capabilities have been implicated in the innate host defense to pathogens.

These microbial molecular markers may be composed of proteins, carbohydrates, lipids, nucleic acids and/or combinations thereof. Individual TLRs recognize distinct pathogen-associated PAMPs, initiating signaling cascades that promote the immune response. Structurally, TLRs are type I transmembrane receptors that possess varying numbers of extracellular N-terminal leucine-rich repeat (LRR) motifs, followed by a cysteine-rich region, a TM domain, and an intracellular Toll/IL-1 R (TIR) motif.

Trk receptors are a family of tyrosine kinases that regulates synaptic strength and plasticity in the mammalian nervous system. These can include transmission of pain, regulation of respiration and more. Trk receptors affect neuronal survival and differentiation through several signal cascades. However, the activation of these receptors also has significant effects on functional properties of neurons.