Synapsin


Synapsin

The synapsins are a family of proteins that have long been implicated in the regulation of neurotransmitter release at synapses. Specifically, they are thought to be involved in regulating the number of synaptic vesicles available for release via exocytosis at any one time.

Synapsins are encoded by three different genes, synapsin I, II and III, and different neuron terminals will encode different amounts of these; synapsin will make up 1% of total brain protein at any one time.

Current studies suggest the following hypothesis for the role of synapsin: synapsins bind synaptic vesicles to components of the cytoskeleton which prevents them from migrating to the presynaptic membrane and releasing transmitter. During an action potential, synapsins are phosphorylated by Ca2+/calmodulin-dependent protein kinase II, releasing the synaptic vesicles and allowing them to move to the membrane and release their neurotransmitter.

Gene knockout studies in mice (where the mouse is unable to produce synapsin) have had some surprising results. Mice lacking all three synapsins are prone to seizures, and experience learning defects cite journal |author=Rosahl TW, Geppert M, Spillane D, Herz J, Hammer RE, Malenka RC, Sudhof TC |title= Short-term synaptic plasticity is altered in micelacking synapsin I |journal=Cell |volume=75 |pages=661–670 |year=1993 |pmid=7902212 |doi= 10.1016/0092-8674(93)90487-B] . These results suggest that while synapsins are not essential for synaptic function, they do serve an important modulatory role. Conversely, studies using transgenic mice in which neuronal signaling is abolished in specific circuitries showed that synaptic activity regulates, but is not essential to maintain, the expression of these proteins cite journal |author=Kihara AH, Santos TO, Paschon V, Matos RJ, Britto LR |title= Lack of photoreceptor signaling alters the expression of specific synaptic proteins in the retina |journal=Neuroscience |volume=151 |pages=995–1005 |year=2008 |pmid=18248909 |doi= 10.1016/j.neuroscience.2007.09.088] .

References


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Look at other dictionaries:

  • synapsin — synapsin. См. синапсин. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • synapsin I — A fibrous phosphoprotein that links synaptic vesicles together in the axon terminal; synapsin I is a substrate for certain kinases; phosphorylation of synapsin I allows release of neurotransmitters …   Medical dictionary

  • synapsin — noun Any of a family of proteins implicated in the regulation of neurotransmitter release at synapses …   Wiktionary

  • SYN1 — Synapsin I, also known as SYN1, is a human gene.cite web | title = Entrez Gene: SYN1 synapsin I| url = http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene Cmd=ShowDetailView TermToSearch=6853| accessdate = ] PBB Summary section title = summary text …   Wikipedia

  • SYN3 — Synapsin III, also known as SYN3, is a human gene.cite web | title = Entrez Gene: SYN3 synapsin III| url = http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene Cmd=ShowDetailView TermToSearch=8224| accessdate = ] PBB Summary section title = summary… …   Wikipedia

  • SYN2 — Synapsin II, also known as SYN2, is a human gene.cite web | title = Entrez Gene: SYN2 synapsin II| url = http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene Cmd=ShowDetailView TermToSearch=6854| accessdate = ] PBB Summary section title = summary… …   Wikipedia

  • синапсин — synapsin синапсин. Белок из семейства нейроноспецифичных фосфопротеинов, обнаруживается в нейронах центральной и периферической нервной системы и играет важную роль в регуляции передачи нервного импульса; ген С. 1 локализован вблизи центромеры Х… …   Молекулярная биология и генетика. Толковый словарь.

  • Синапсины — семейство фосфопротеинов, регулирующих процесс выброса нейромедиаторов в синапсах. Они обильно покрывают поверхность синаптических пузырьков. В зрелых нейронах наиболее сильно экспрессированы синапсины 1 и 2. Синапсин 3 обнаруживается в… …   Википедия

  • Gluten-sensitive idiopathic neuropathies — Diagnosis of gluten sensitive neuropathies without a clear cause is on the rise. These idiopathic neuropathies were first identified by screening for anti gliadin IgG (AGA).cite journal | author = Hadjivassiliou M, Gibson A, Davies Jones GA, Lobo …   Wikipedia

  • OGT (gene) — O linked N acetylglucosamine (GlcNAc) transferase (UDP N acetylglucosamine:polypeptide N acetylglucosaminyl transferase) PDB rendering based on 1w3b …   Wikipedia


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