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Somatostatin Receptors
Somatostatin receptors are receptors for the ligand somatostatin, a small neuropeptide associated with neural signaling, particularly in the post-synaptic response to NMDA receptor co-stimulation/activation. Somatostatin is encoded by a CRE and is very susceptible to gene promoter region activation by transcription factor CREB. There are five known somatostatin receptors: * SST1 () * SST2 () * SST3 () * SST4 () * SST5 () All are G protein-coupled seven transmembrane receptor G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of protein family, evolution ...s. References External links * G protein-coupled receptors {{transmembranereceptor-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatostatin Receptor 1
Somatostatin receptor type 1 is a protein that in humans is encoded by the ''SSTR1'' gene. Function Somatostatin acts at many sites to inhibit the release of many hormones and other secretory proteins. The biological effects of somatostatin are probably mediated by a family of G protein-coupled receptors that are expressed in a tissue-specific manner. The encoded protein is a member of the superfamily of somatostatin receptors having seven transmembrane segments, and is expressed in highest levels in jejunum and stomach. See also * Somatostatin receptor Somatostatin receptors are receptors for the ligand somatostatin, a small neuropeptide associated with neural signaling, particularly in the post-synaptic response to NMDA receptor co-stimulation/activation. Somatostatin is encoded by a CRE ... References Further reading * * * * * * * * * * * * * * * * * * * External links * * G protein-coupled receptors {{transmembranerecept ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatostatin Receptor 2
Somatostatin receptor type 2 is a protein that in humans is encoded by the ''SSTR2'' gene. The SSTR2 gene is located on chromosome 17 on the long arm in position 25.1 in humans. It is also found in most other vertebrates. The somatostatin receptor 2 (SSTR2), which belongs to the G-protein coupled receptor family, is a protein which is most highly expressed in the pancreas (both alpha- and beta-cells), but also in other tissues such as the cerebrum and kidney and in lower amount in the jejunum, colon and liver. In the pancreas, after binding to somatostatin, it inhibits the secretion of pancreatic enzymes. During development, it stimulates neuronal migration and axon outgrowth. The somatostatin receptor 2 is expressed in most tumors. Patients with neuroendocrine tumors that over-express the somatostatin receptor 2 have an improved prognosis. The over expression of SSTR2 in tumors can be exploited to selectively deliver radio-peptides to tumors to either detect or destroy them. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatostatin Receptor 3
Shekel Somatostatin receptor type 3 is a protein that in humans is encoded by the ''SSTR3'' gene. Function Somatostatin acts at many sites to inhibit the release of many hormones and other secretory proteins. The biological effects of somatostatin are probably mediated by a family of G protein-coupled receptors that are expressed in a tissue-specific manner. SSTR3 is a member of the superfamily of receptors having seven transmembrane segments and is expressed in highest levels in brain and pancreatic islets. SSTR3 is functionally coupled to adenylyl cyclase. See also * Somatostatin receptor Somatostatin receptors are receptors for the ligand somatostatin, a small neuropeptide associated with neural signaling, particularly in the post-synaptic response to NMDA receptor co-stimulation/activation. Somatostatin is encoded by a CRE ... References Further reading * * * * * * * * * * * * * * * * * * External links * * {{NLM content G ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatostatin Receptor 4
Somatostatin receptor type 4 is a protein that in humans is encoded by the ''SSTR4'' gene. Function Somatostatin acts at many sites to inhibit the release of many hormones and other secretory proteins. The biologic effects of somatostatin are probably mediated by a family of G protein-coupled receptors that are expressed in a tissue-specific manner. SSTR4 is a member of the superfamily of receptors having seven transmembrane segments and is expressed in highest levels in fetal and adult brain and lung. See also * Somatostatin receptor Somatostatin receptors are receptors for the ligand somatostatin, a small neuropeptide associated with neural signaling, particularly in the post-synaptic response to NMDA receptor co-stimulation/activation. Somatostatin is encoded by a CRE ... References Further reading * * * * * * * * * * * * * * * * * External links * * G protein-coupled receptors {{transmembranereceptor-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatostatin Receptor 5
Somatostatin receptor type 5 is a protein that in humans is encoded by the ''SSTR5'' gene. Somatostatin acts at many sites to inhibit the release of many hormones and other secretory proteins. The biological effects of somatostatin are probably mediated by a family of G protein-coupled receptors that are expressed in a tissue-specific manner. SSTR5 is a member of the superfamily of receptors having seven transmembrane segments. See also * Somatostatin receptor Somatostatin receptors are receptors for the ligand somatostatin, a small neuropeptide associated with neural signaling, particularly in the post-synaptic response to NMDA receptor co-stimulation/activation. Somatostatin is encoded by a CRE ... References Further reading * * * * * * * * * * * * * * * * * * * External links * * G protein-coupled receptors {{transmembranereceptor-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligand
In coordination chemistry, a ligand is an ion or molecule (functional group) that binds to a central metal atom to form a coordination complex. The bonding with the metal generally involves formal donation of one or more of the ligand's electron pairs, often through Lewis bases. The nature of metal–ligand bonding can range from covalent to ionic. Furthermore, the metal–ligand bond order can range from one to three. Ligands are viewed as Lewis bases, although rare cases are known to involve Lewis acidic "ligands". Metals and metalloids are bound to ligands in almost all circumstances, although gaseous "naked" metal ions can be generated in a high vacuum. Ligands in a complex dictate the reactivity of the central atom, including ligand substitution rates, the reactivity of the ligands themselves, and redox. Ligand selection requires critical consideration in many practical areas, including bioinorganic and medicinal chemistry, homogeneous catalysis, and environmental chemi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Somatostatin
Somatostatin, also known as growth hormone-inhibiting hormone (GHIH) or by several other names, is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G protein-coupled somatostatin receptors and inhibition of the release of numerous secondary hormones. Somatostatin inhibits insulin and glucagon secretion. Somatostatin has two active forms produced by the alternative cleavage of a single preproprotein: one consisting of 14 amino acids (shown in infobox to right), the other consisting of 28 amino acids. Among the vertebrates, there exist six different somatostatin genes that have been named ''SS1, SS2, SS3, SS4, SS5'' and ''SS6''. Zebrafish have all six. The six different genes, along with the five different somatostatin receptors, allow somatostatin to possess a large range of functions. Humans have only one somatostatin gene, ''SST''. Nomenclature Synonyms of "somatostatin" include: * growth hormone ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neuropeptide
Neuropeptides are chemical messengers made up of small chains of amino acids that are synthesized and released by neurons. Neuropeptides typically bind to G protein-coupled receptors (GPCRs) to modulate neural activity and other tissues like the gut, muscles, and heart. There are over 100 known neuropeptides, representing the largest and most diverse class of signaling molecules in the nervous system. Neuropeptides are synthesized from large precursor proteins which are cleaved and post-translationally processed then packaged into dense core vesicles. Neuropeptides are often co-released with other neuropeptides and neurotransmitters in a single neuron, yielding a multitude of effects. Once released, neuropeptides can diffuse widely to affect a broad range of targets. Synthesis Neuropeptides are synthesized from large, inactive precursor proteins called prepropeptides. Prepropeptides contain sequences for a family of distinct peptides and often contain repeated copies of the sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post-synaptic
Chemical synapses are biological junctions through which neurons' signals can be sent to each other and to non-neuronal cells such as those in muscles or glands. Chemical synapses allow neurons to form circuits within the central nervous system. They are crucial to the biological computations that underlie perception and thought. They allow the nervous system to connect to and control other systems of the body. At a chemical synapse, one neuron releases neurotransmitter molecules into a small space (the synaptic cleft) that is adjacent to another neuron. The neurotransmitters are contained within small sacs called synaptic vesicles, and are released into the synaptic cleft by exocytosis. These molecules then bind to neurotransmitter receptors on the postsynaptic cell. Finally, the neurotransmitters are cleared from the synapse through one of several potential mechanisms including enzymatic degradation or re-uptake by specific transporters either on the presynaptic cel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NMDA Receptor
The ''N''-methyl-D-aspartate receptor (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 receptor, AMPA and kainate receptors. Depending on its subunit composition, its Ligand (biochemistry), ligands are glutamate and glycine (or D-Serine, D-serine). However, the binding of the ligands is typically not sufficient to open the channel as it may be blocked by Magnesium, 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 cation, 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. The NMDA receptor is ionotropic, meaning it is a pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Promoter (genetics)
In genetics, a promoter is a sequence of DNA to which proteins bind to initiate transcription of a single RNA transcript from the DNA downstream of the promoter. The RNA transcript may encode a protein (mRNA), or can have a function in and of itself, such as tRNA or rRNA. Promoters are located near the transcription start sites of genes, upstream on the DNA (towards the 5' region of the sense strand). Promoters can be about 100–1000 base pairs long, the sequence of which is highly dependent on the gene and product of transcription, type or class of RNA polymerase recruited to the site, and species of organism. Promoters control gene expression in bacteria and eukaryotes. RNA polymerase must attach to DNA near a gene for transcription to occur. Promoter DNA sequences provide an enzyme binding site. The -10 sequence is TATAAT. -35 sequences are conserved on average, but not in most promoters. Artificial promoters with conserved -10 and -35 elements transcribe more slowly. All D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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