Neuronal calcium sensor-1 (NCS-1) also known as frequenin homolog (Drosophila) (freq) is a protein that is encoded by the ''FREQ''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

in humans. NCS-1 is a member of the

neuronal calcium sensor Neuronal Calcium Sensor is a large family of proteins which work as calcium dependent molecular switches and includes members like Frequenin (NCS1), recoverin, GCAP, neurocalcin, visinin etc. All the members carry 4 EF hand motifs (out of which only ...

family, a class of

EF hand The EF hand is a helix–loop–helix structural domain or ''motif'' found in a large family of calcium-binding proteins. The EF-hand motif contains a helix–loop–helix topology, much like the spread thumb and forefinger of the human hand, i ...

containing calcium-myristoyl-switch proteins.

Function

NCS-1 regulates synaptic transmission, helps control the dynamics of nerve terminal growth, is critical for some forms of learning and

memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembered, ...

in '' C. elegans'' and mammals, regulates corticohippocampal

plasticity Plasticity may refer to: Science * Plasticity (physics), in engineering and physics, the propensity of a solid material to undergo permanent deformation under load * Neuroplasticity, in neuroscience, how entire brain structures, and the brain it ...

; and enhancing levels of NCS-1 in the mouse

dentate gyrus The dentate gyrus (DG) is part of the hippocampal formation in the temporal lobe of the brain, which also includes the hippocampus and the subiculum. The dentate gyrus is part of the hippocampal trisynaptic circuit and is thought to contribut ...

increases spontaneous exploration of safe environments, potentially linking NCS-1 to curiosity. NCS-1 is a calcium sensor, not a calcium buffer (

chelator Chelation is a type of bonding of ions and molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central metal atom. These ligands ar ...

); thus it is a high-affinity, low-capacity, calcium-binding protein. Frq can substitute for calmodulin in some situations. It is thought to be associated with neuronal secretory vesicles and regulate neurosecretion. # It is the Ca²⁺-sensing subunit of the yeast phosphatidylinositol (PtdIns)-4-OH kinase, PIK1 # It binds to many proteins, some in calcium dependent and some in calcium independent ways, and switches many of the targets "on" (some off). ##

Calcineurin Calcineurin (CaN) is a calcium and calmodulin dependent serine/threonine protein phosphatase (also known as protein phosphatase 3, and calcium-dependent serine-threonine phosphatase). It activates the T cells of the immune system and can be blo ...

(protein phosphatase 2B) ##

GRK2 G-protein-coupled receptor kinase 2 (GRK2) is an enzyme that in humans is encoded by the ''ADRBK1'' gene. GRK2 was initially called Beta-adrenergic receptor kinase (βARK or βARK1), and is a member of the G protein-coupled receptor kinase subfam ...

(G-protein-coupled receptor kinase 2) ## D₂ dopamine receptor ## IL1RAPL1 (interleukin-1 receptor accessory protein-like 1 protein) ## PI4KIIIβ (type III phosphatidylinositol 4-kinase β) ##

IP3 receptor Inositol trisphosphate receptor (InsP3R) is a membrane glycoprotein complex acting as a Ca2+ channel activated by inositol trisphosphate (InsP3). InsP3R is very diverse among organisms, and is necessary for the control of cellular and physio ...

(this activity is inhibited by lithium - a drug used for the treatment of

bipolar disorder Bipolar disorder, previously known as manic depression, is a mental disorder characterized by periods of depression and periods of abnormally elevated mood that last from days to weeks each. If the elevated mood is severe or associated with ...

) ## 3',5'-cyclic nucleotide

phosphodiesterase A phosphodiesterase (PDE) is an enzyme that breaks a phosphodiester bond. Usually, ''phosphodiesterase'' refers to cyclic nucleotide phosphodiesterases, which have great clinical significance and are described below. However, there are many oth ...

s ##

ARF1 ADP-ribosylation factor 1 is a protein that in humans is encoded by the ''ARF1'' gene. Function ADP-ribosylation factor 1 (ARF1) is a member of the human ARF gene family. The family members encode small guanine nucleotide-binding proteins tha ...

(

ADP Adp or ADP may refer to: Aviation * Aéroports de Paris, airport authority for the Parisian region in France * Aeropuertos del Perú, airport operator for airports in northern Peru * SLAF Anuradhapura, an airport in Sri Lanka * Ampara Airp ...

Ribosylation factor 1) ## A type ( K_v4.3; Shal-related subfamily, member 3)

voltage-gated potassium channel Voltage-gated potassium channels (VGKCs) are transmembrane channels specific for potassium and sensitive to voltage changes in the cell's membrane potential. During action potentials, they play a crucial role in returning the depolarized ce ...

s ##

Nitric oxide synthase Nitric oxide synthases () (NOSs) are a family of enzymes catalyzing the production of nitric oxide (NO) from L-arginine. NO is an important cellular signaling molecule. It helps modulate vascular tone, insulin secretion, airway tone, and peris ...

TRPC5 Short transient receptor potential channel 5 (TrpC5) also known as transient receptor protein 5 (TRP-5) is a protein that in humans is encoded by the ''TRPC5'' gene. TrpC5 is subtype of the TRPC family of mammalian transient receptor potential io ...

channel ## Ric8a # Frq modulates Ca²⁺ entry through a functional interaction with the α₁ voltage-gated Ca²⁺-channel subunit.

Structure

NCS-1 is a globular protein consisting of ten alpha-helices. Four pairs of alpha-helices each form independent 12-amino-acid loops containing a negatively charged calcium binding domain known as an EF-hand. However, only three of these EF hands are functional (the most N-terminal EF-hand does not bind calcium). They could be occupied not only by calcium but also by magnesium and zinc ions. NCS-1 also contains at least two known protein binding domains, and a large surface exposed hydrophobic crevice containing EF-hands three and four. There is a

myristoylation Myristoylation is a lipidation modification where a myristoyl group, derived from myristic acid, is covalently attached by an amide bond to the alpha-amino group of an N-terminal glycine residue. Myristic acid is a 14-carbon saturated fatty a ...

motif at the N-terminus that presumably allows NCS-1 to associate with

lipid Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include ...

membranes.

Clinical significance

The expression of NCS-1 increases in

and some forms of

schizophrenia Schizophrenia is a mental disorder characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, and disorganized thinking. Other symptoms include social withdra ...

and decreases in

inflammatory bowel disease Inflammatory bowel disease (IBD) is a group of inflammatory conditions of the colon and small intestine, Crohn's disease and ulcerative colitis being the principal types. Crohn's disease affects the small intestine and large intestine, as well ...

. NCS-1 has also been linked with Autism. In addition NCS-1 is significant in intelligence in creating curiosity by its function on dopamine D2 receptors in the dentate gyrus, increasing memory for complex tasks. http://www.physorg.com/news172174436.html

History

NCS-1 was originally discovered in ''

Drosophila ''Drosophila'' () is a genus of flies, belonging to the family Drosophilidae, whose members are often called "small fruit flies" or (less frequently) pomace flies, vinegar flies, or wine flies, a reference to the characteristic of many species ...

'' as a gain-of-function mutation associated with frequency-dependent increases in

neurotransmission Neurotransmission (Latin: ''transmissio'' "passage, crossing" from ''transmittere'' "send, let through") is the process by which signaling molecules called neurotransmitters are released by the axon terminal of a neuron (the presynaptic neuron), ...

. A role in neurotransmission was later confirmed in ''

'' using ''frq'' null mutants. Work in bovine

chromaffin cell Chromaffin cells, also called pheochromocytes (or phaeochromocytes), are neuroendocrine cells found mostly in the medulla of the adrenal glands in mammals. These cells serve a variety of functions such as serving as a response to stress, monitori ...

s demonstrated that NCS-1 is also a modulator of neurotransmission in mammals. The designation 'NCS-1' came from the assumption that the protein was expressed only in neuronal cell types, which is not the case.

References

External links