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Topic: Second messenger

Related Topics

Signal transduction

Transmembrane receptor

Cyclic AMP

Hydrophobe

Cell membrane

G protein

CGMP

Intracellular

Biological cell

Cyclic adenosine monophosphate

CREB

Diffusion

GTP

Protein

Human serotonin transporter gene

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	BioG 101-102 -- Self-Test (Site not responding. Last check: 2007-10-21)
		Second messengers are non-protein components of a cellular signal transduction pathway (the figure below shows the second messenger cyclic AMP).
		The proteins that bind to the second messenger should already be present before there is a rise in the concentration of the second messenger.
		After the rise in the concentration of second messenger, it must be removed quickly by degradation or export from the cytosol.
	biog-101-104.bio.cornell.edu /BioG101_104/BioG101_Tutor/Quiz_8/m08_q02.html (141 words)

	Module 7
		Second, the pre-synaptic cell may use a reuptake mechanism that brings the molecules in question back into the terminal button so that they may be used again later (See figure 7.1).
		The second messenger system (metabotropic receptors), also requires binding between a NT and a receptor, however the receptor is not directly coupled to the ion channel.
		Thus, a NT using a second messenger mechanism to elicit modulatory NT effects is said to be conditional since the actions of the modulating NT must require the presence of another NT to be modulated.
	cogsci.ucsd.edu /~pineda/guide/module_07.html (2291 words)

	kjhollen :: second messenger
		Second Messenger is a project I worked on with Joan Morris DiMicco from the Electronic Publishing group at the MIT Media Lab.
		Second Messenger collects and transcribes data in real time, so it can be used for instant group feedback or for playback at a later date.
		Second Messenger processes the volume levels for each microphone to determine whether or not each group member is speaking.
	web.mit.edu /kjhollen/www/secondmessenger.html (892 words)

	A Brief Introduction to the Brain:Second Messengers
		Synaptic actions by second messengers can close ion channels that are open at the resting potential, thereby decreasing the conductance of the membrane.
		Induction of a cascade of second messengers involves the recognition of specific extracellular signals (i.e., hormones, neurotransmitters, neuromodulators, growth factors, etc.) and activation of effectors.
		These second messengers trigger biochemical cascade either activating specific protein kinases (phosphate transferring proteins) that phosphorylate a variety of cellular proteins (thereby altering their activities), or mobilizing Ca ions from intracellular stores, thus initiating the reactions that changes the cells biochemical state.
	ifcsun1.ifisiol.unam.mx /Brain/secmen.htm (1049 words)

	Second Messengers
		Second messengers are intracellular molecules or ion that are regulated by extracellular signaling agents such as neurotransmitters and hormones (first messengers).
		Second messengers typically operate by activating protein kinases that phosphorylate carious target proteins, thereby altering the functioning of these proseins.
		Second messengers modulate a wide range of both rapid and long-term neuronal processes.
	www.chemistry.emory.edu /justice/seminar/second.htm (666 words)

	Cell Signaling III: Other Second Messenger Systems
		A second effect of the rise in Ca in the cytoplasm as a result of the IP is the activation of a calcium binding protein called calmodulin.
		However, it’s already clear that the various second messenger systems that exist (I haven’t mentioned them all) don’t operate independently but interact in ways that can either augment a response when two pathways are activated and augment each other, or cancel a response when the two pathways inhibit each other.
		The use of such activators and inhibitors has proved invaluable in establishing which second messengers are part of which responses; similar strategies are used in all signaling systems that have been studied.
	www.lclark.edu /~reiness/cellbio/lectures/lect24.htm (2560 words)

	Introducing doseresponse curves
		For example, the response might be enzyme activity, accumulation of an intracellular second messenger, membrane potential, secretion of a hormone, heart rate or contraction of a muscle.
		If you assume that the production of second messenger is proportional to receptor occupancy, the graph of agonist concentration vs. second messenger concentration will have the same shape as receptor occupancy (a hyperbola if plotted on a linear scale, a sigmoid curve with a slope factor of 1.0 if plotted as a semilog graph).
		If the second messenger works by binding to an effector, and that binding step follows the law of mass action, then the graph of second messenger concentration vs. response will also have that same standard shape.
	dwb.unl.edu /Teacher/NSF/C03/C03Links/www.curvefit.com/introduction89.htm (939 words)

	Second Messengers
		Second messengers are molecules that relay signals received at receptors on the cell surface — such as the arrival of protein hormones, growth factors, etc. — to target molecules in the cytosol and/or nucleus.
		But in addition to their job as relay molecules, second messengers serve to greatly amplify the strength of the signal.
		Cyclic GMP is synthesized from the nucleotide GTP using the enzyme guanylyl cyclase.
	users.rcn.com /jkimball.ma.ultranet/BiologyPages/S/Second_messengers.html (821 words)

	Lecture #13
		A second second messenger system was discovered in the late 1960s that used not cAMP but cyclic GMP (cGMP) as the second messenger.
		A second effect of the rise in Ca in the cytoplasm as a result of the InsP3 is the activation of a calcium binding protein called calmodulin.
		However, it’s already clear that the various second messenger systems that exist (I haven’t mentioned them all) don’t operate independently but interact in ways that can either augment a response when two pathways are activated and enhance each other, or cancel a response when the two pathways inhibit each other.
	www.lclark.edu /~reiness/neurobiology/Lectures/lecture16.htm (1707 words)

	FEBS Abstract
		Not only is the cell full of different organelles, but the cytoplasm itself is highly viscous and structured because of the high density of proteins and because of the presence of an intricate network of filamentous proteins, the so called cytoskeleton.
		Essentially three parameters are theoretically involved in the formation of local second messenger gradients: (i) localized site of generation; (ii) of degradation-accumulation; and (iii) diffusion rates of the molecule within the cytosol.
		In order to understand the functional importance of such heterogeneity it is compelling to monitor the dynamics of second messenger concentration in living cells with utmost spatial and temporal accuracy.
	www.blackwellpublishing.com /febsabstracts2004/abstract.asp?id=17861 (220 words)

	Mechanism of Action: Hormones with Cell Surface Receptors
		The second messengers then trigger a series of molecular interactions that alter the physiologic state of the cell.
		In the scenario described, you are the "first messenger", the dispatcher is "receptor", the firefighters are "second messengers".
		As was seen with cAMP second messenger systems, activation of receptor tyrosine kinases leads to rapid modulation in a number of target proteins within the cell.
	arbl.cvmbs.colostate.edu /hbooks/pathphys/endocrine/moaction/surface.html (1322 words)

	Signal Transduction Pathways for Catecholamine Receptors
		For example, to support a second messenger role of cAMP in the electrophysiological actions of a catecholamine receptor, it is necessary to show that agents that directly activate the cAMP pathway mimic receptor activation.
		These modulatory effects, which are mediated predominantly if not solely via intracellular messenger pathways, include regulation of the activity of receptors, ion channels, second messenger effector enzymes, and neurotransmitter synthetic enzymes, as well as regulation of the synthesis and degradation of these and other neuronal proteins.
		Proteins that control the synthesis of the cyclic nucleotide second messengers (adenylyl cyclase and guanylyl cyclase), as well as the degradation of cyclic nucleotides (phosphodiesterases), are regulated by phosphorylation.
	www.acnp.org /G4/GN401000028/CH.html (7925 words)

	Molecular Neurobiology for Practicing Physicians, Part 2: How Neurotransmitters Activate Second Messenger ... (Site not responding. Last check: 2007-10-21)
		A second messenger system includes several elements: (1) the first messenger (neurotransmitter), (2) the neurotransmitter's receptor, (3) a second receptor called a G protein that interacts with the neurotransmitter receptor, (4) an enzyme triggered into action by the interacting pair of receptors, and (5) a second messenger molecule manufactured by this enzyme.
		The systems that produce these second messengers are also sometimes known as the cyclic AMP second messenger system, and the PI second messenger system, respectively.
		Thus, the handoff of first messenger to second messenger is accomplished by means of a molecular cascade: neurotransmitter to neurotransmitter receptor (Figure 1); neurotransmitter receptor to G protein (Figure 2); binary complex of 2 receptors to enzyme (Figure 3); and enzyme to second messenger molecule (Figure 4).
	www.psychiatrist.com /pcc/brainstorm/br6010.htm (367 words)

	Sensitization and Conditioning in Aplysia: Cellular mechansisms
		Examples of second messengers are cyclic adenosine monophosphase (cAMP), inositol triphosphase (IP3), diacylglycerol (DAG), arachidonic acid.
		Either the G protein or the second messenger then act on a channel to modify ionic across the cell membrane.
		The second messenger can also activate a secondary effector, such as a protein kinase, which acts on the channel.
	hebb.mit.edu /courses/9.03/lecture3.html (586 words)

	Examples: Modulation \| SNNAP - Simulator for Neural Networks and Action Potentials
		The osc.smu simulation was extended to include intracellular pools of transmitters (.tr) and second* messengers (.sm), a modulatory synapses (.ms) and homo- and heterosynaptic plasticity.
		Before the second current pulse, the second messenger system in cell 'a' is activated with a treatment.
		The second messenger, in turn, modulates one of the membrane conductances in cell 'a'.
	www.uth.tmc.edu /SNNAP/content/examples_modulation.htm (1257 words)

	Signal Transduction
		In the case of ligand-gated (ion channel) receptors, the influx of ions serves as a second messenger.
		The ultimate end-point is regulation of gene transcription to produce messenger RNA (mRNA) and the subsequent translation of mRNA to produce a protein specific to that gene.
		A second messenger refers to an intracellular signaling molecule or system that is downstream from the receptor.
	www.uchsc.edu /sm/psych/ppfr/signal_transduction.htm (634 words)

	Second messenger system - Wikipedia, the free encyclopedia
		A Second messenger system is a method of cellular signaling where the signalling molecule does not enter the cell, but rather utilizes a cascade of events that transduces the signal into a cellular change.
		Second messenger systems utilize receptors on the surface of the plasma membrane which are generally coupled to a kinase on the interior surface of the membrane.
		The kinase then phosphorylates another molecule (frequently cAMP) which carries out a further action.
	en.wikipedia.org /wiki/Second_messenger_system (118 words)

	Obesity Drug? - 'Second messenger' NAADP shows fast, dose-related impact on satiety cycle
		Results of a new study "establishes NAADP as a new second messenger, and the study of this novel molecule has potential to extend its clinical significance, possibly as a candidate for treating obesity," according to the lead author, Michiko Yamasaki at the Department of Pharmacology, University of Oxford, United Kingdom.
		Cholecystokinin is a first messenger that tells cells to release digestive enzymes in the pancreas and to cause satiety in the brain.
		However the potential of this new messenger as a therapeutic target should not be underestimated," she added.
	www.medicalnewstoday.com /medicalnews.php?newsid=22180&nfid=rssfeeds (1030 words)

	Windows XP Common Issues > Windows Messenger Uninstall/MSN Messenger
		MSN Messenger is more of the home client allowing you to send messages to mobile devices and have real time alerts to new email if you are using a hotmail account, Since MSN 6.0 it has also included a much more 'fun' user interface and features to match.
		If you require a messenger version capable of connecting to a Microsoft Exchange IM or SIP servers do not uninstall your existing version of messenger from your system, MSN Messenger is not capable of connecting to these types of servers, if you required these features install Windows Messenger 5.0 (not distributed through Windows Update).
		There is a benefit of having a second messenger installed on the machine, which is that you are able to login to the messenger service with two different passport accounts at the same time.
	www.mvps.org /marksxp/WindowsXP/messenger/messenger.php (644 words)

	A Diffusion-Translocation Model for Gradient Sensing by Chemotactic Cells -- Postma and Van Haastert 81 (3): 1314 -- ...
		The effect of second messenger degradation on signal localization is complementary to that of diffusion speed, due to the
		and the second messenger in the plasma membrane.
		to the identity of the second messenger in the membrane as the
	www.biophysj.org /cgi/content/full/81/3/1314 (5121 words)

	NASA - MESSENGER - Unlocking the Secrets of Mercury
		The MESSENGER mission, spacecraft, and science instruments are focused on answering six key outstanding questions that will allow us to better understand Mercury as a planet.
		The launch of NASA's MESSENGER spacecraft aboard a Boeing Delta II rocket was postponed this morning due to lightning potential from residual clouds that were associated with Tropical Storm Alex.
		MESSENGER is successfully launched on its journey to Mercury.
	www.nasa.gov /mission_pages/messenger/main (377 words)

	ARS \| Publication request: Pharmacology of Stomoxytachykinin Receptor Depends on Second Messenger System
		The basic premise of this research is that neuropeptides (short chains of amino acids) serve as potent messengers in insects to regulate vital functions.
		Nevertheless, these neuropeptides in and of themselves hold little promise as pest control agents because of susceptibility to being degraded in the target pest, and inability to pass through the outside skin (cuticle) and/or digestive tract.
		We must design neuropeptide mimics that resist degradation by enzymes in the digestive tract and blood of pest insects and interact with the active site within the agricultural pest in such a way as to either over-activate or block critical, neuropeptide-regulated life functions.
	www.ars.usda.gov /research/publications/Publications.htm?seq_no_115=173117&pf=1 (394 words)

	[No title]
		describe the cAMP second messenger system and including the mechanism by which its production is increased, the mechanism by which it alters cell function, and the mechanism by which its action is terminated.
		describe the IP3 and DAG second messenger system including the mechanism by which their production is increased, the mechanism by which each alters cells function, and the role played by G-proteins in its inactivation.
		describe Ca++ as a second messenger including mechanisms by which intracellular concentrations are increased and the molecular form in which it exerts its action.
	www.ursa.kcom.edu /Department/LectureNotes/Spring/SigTransduction.doc (2030 words)

	Millipore - Technical Library - Second Messenger Assays Using the MultiScreen System
		Assays on enzymes involved with second messenger-mediated systems are essential in determining the regulatory pathways of the cell.
		The basic solid phase assay to determine their presence and activity usually involves incubation of a crude or purified preparation with a substrate, followed by precipitation of the product on a membrane filter using trichloroacetic acid, and scintillation counting.
		Plates are primarily counted directly in microplate scintillation counters, or a punch assembly transfers 8 of the filters at a time into scintillation vials.
	www.millipore.com /publications.nsf/docs/an457 (2732 words)

	Second Messenger Systems
		Second messenger systems are complexes of regulatory (eg, G-proteins) and catalytic (eg, adenylate cyclase, phospholipase C) proteins, which are activated by NTs (first messengers) to form specific chemicals or second messengers (eg, cAMP, inositol triphosphate or IP3, diacylglycerol or DAG).
		Here, the first messenger (NT, hormone) binds to the receptor activating a stimulatory G-protein (Gs) by displacing guanosine diphosphate (GDP) with guanosine triphosphate (GTP).
		The activated protein amplifies the signal of the first messenger and activates adenylate cyclase.
	secondmessengersystems.blogspot.com (376 words)

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