Page last updated: 2024-10-24

juxtaparanode region of axon

Definition

Target type: cellularcomponent

A region of an axon near a node of Ranvier that is between the paranode and internode regions. [GOC:BHF, GOC:jl, PMID:10624965, PMID:14682359]

The juxtaparanode region of an axon is a specialized domain located at the transition zone between the myelinated and unmyelinated segments of the axon. It is characterized by a unique and complex arrangement of cellular components that play crucial roles in maintaining axonal integrity and facilitating signal propagation.

The juxtaparanode region is enriched in a variety of proteins, including:

* **Adhesion molecules:** These molecules, such as neurofascin 155 (NF155), contactin-associated protein 1 (Caspr1), and contactin, mediate the interactions between the axon and the myelinating glial cell (Schwann cell in the peripheral nervous system and oligodendrocyte in the central nervous system). They form a specialized adhesion complex at the juxtaparanode, ensuring the stability and proper alignment of the myelin sheath.
* **Ion channels:** Voltage-gated potassium channels (Kv1.1 and Kv1.2) are concentrated at the juxtaparanode. They play a critical role in regulating the propagation of action potentials along the axon by controlling the repolarization phase of the action potential.
* **Signaling molecules:** Several signaling molecules, such as the tyrosine kinase Fyn and the scaffold protein PSD-95, are also enriched in the juxtaparanode. These molecules are involved in regulating the assembly and function of the juxtaparanode complex and may also contribute to the formation of the myelin sheath.

The cytoskeleton of the juxtaparanode region is also unique, with an abundance of microtubules and actin filaments. These cytoskeletal components provide structural support for the axon and play a role in maintaining the organization of the juxtaparanode complex.

Furthermore, the juxtaparanode region contains specialized membrane domains called paranodal loops. These loops are formed by the myelinating glial cell and extend around the axon. They serve as barriers to diffusion and contribute to the formation of the high-resistance seal at the paranode, which is essential for efficient saltatory conduction of action potentials.

The juxtaparanode region is therefore a complex and dynamic structure that plays a critical role in maintaining axonal function. Its unique composition of proteins, ion channels, signaling molecules, and cytoskeletal elements allows it to regulate the propagation of action potentials, ensure the stability of the myelin sheath, and contribute to the overall health of the axon.'
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Proteins (6)

ProteinDefinitionTaxonomy
Potassium voltage-gated channel subfamily A member 2A voltage-gated potassium channel subunit KCNA2 that is encoded in the genome of human. []Homo sapiens (human)
Potassium voltage-gated channel subfamily A member 1A voltage-gated potassium channel subunit KCNA1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q09470]Homo sapiens (human)
NAD-dependent protein deacetylase sirtuin-2An NAD-dependent protein deacetylase sirtuin-2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q8IXJ6]Homo sapiens (human)
Potassium voltage-gated channel subfamily A member 1A voltage-gated potassium channel subunit KCNA1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q09470]Homo sapiens (human)
Disks large homolog 4A disks large homolog 4 that is encoded in the genome of human. [PRO:DNx, UniProtKB:P78352]Homo sapiens (human)
Potassium voltage-gated channel subfamily A member 2A voltage-gated potassium channel subunit KCNA2 that is encoded in the genome of human. []Homo sapiens (human)

Compounds (47)

CompoundDefinitionClassesRoles
niacinamidenicotinamide : A pyridinecarboxamide that is pyridine in which the hydrogen at position 3 is replaced by a carboxamide group.pyridine alkaloid;
pyridinecarboxamide;
vitamin B3
anti-inflammatory agent;
antioxidant;
cofactor;
EC 2.4.2.30 (NAD(+) ADP-ribosyltransferase) inhibitor;
EC 3.5.1.98 (histone deacetylase) inhibitor;
Escherichia coli metabolite;
geroprotector;
human urinary metabolite;
metabolite;
mouse metabolite;
neuroprotective agent;
Saccharomyces cerevisiae metabolite;
Sir2 inhibitor
4-aminopyridineaminopyridine;
aromatic amine
avicide;
orphan drug;
potassium channel blocker
N-(2-aminoethyl)-5-chloro-1-naphthalenesulfonamidenaphthalenes;
sulfonic acid derivative
5-methoxypsoralen5-methoxypsoralen : A 5-methoxyfurocoumarin that is psoralen substituted by a methoxy group at position 5.

5-Methoxypsoralen: A linear furanocoumarin that has phototoxic and anti-inflammatory properties, with effects similar to METHOXSALEN. It is used in PUVA THERAPY for the treatment of PSORIASIS.
5-methoxyfurocoumarin;
organic heterotricyclic compound;
psoralens
hepatoprotective agent;
plant metabolite
bisindolylmaleimide ibisindolylmaleimide I: a bis(indolyl)maleimide
2-(1-(2-(1-methylpyrrolidino)ethyl)-1h-indol-3-yl)maleimidebisindolylmaleimide II: protein kinase C inhibitor; see also bisindolylmaleimide I
bisindolylmaleimide ivindoles;
maleimides
bisindolylmaleimide vbisindolylmaleimide V: used as a negative control compound for protein kinase C inhibition; structure in first source;indoles
flecainideflecainide : A monocarboxylic acid amide obtained by formal condensation of the carboxy group of 2,5-bis(2,2,2-trifluoroethoxy)benzoic acid with the primary amino group of piperidin-2-ylmethylamine. An antiarrhythmic agent used (in the form of its acetate salt) to prevent and treat tachyarrhythmia (abnormal fast rhythm of the heart).

Flecainide: A potent anti-arrhythmia agent, effective in a wide range of ventricular and atrial ARRHYTHMIAS and TACHYCARDIAS.
aromatic ether;
monocarboxylic acid amide;
organofluorine compound;
piperidines
anti-arrhythmia drug
go 6976indolocarbazole;
organic heterohexacyclic compound
EC 2.7.11.13 (protein kinase C) inhibitor
idebenone1,4-benzoquinones;
primary alcohol
antioxidant;
ferroptosis inhibitor
nsc 664704kenpaullone : An indolobenzazepine that is paullone in which the hydrogen at position 9 is replaced by a bromo substituent. It is an ATP-competitive inhibitor of cyclin-dependent kinases (CDKs) and glycogen synthase kinase 3beta (GSK3beta).

kenpaullone: inhibits CDK1/cyclin B; structure in first source
indolobenzazepine;
lactam;
organobromine compound
cardioprotective agent;
EC 2.7.11.22 (cyclin-dependent kinase) inhibitor;
EC 2.7.11.26 (tau-protein kinase) inhibitor;
geroprotector
fenamic acidfenamic acid : An aminobenzoic acid that is the N-phenyl derivative of anthranilic acid. It acts as a parent skeleton for the synthesis of several non-steroidal anti-inflammatory drugs.

fenamic acid: has chloride and potassium channel-blocking activity; RN given refers to parent cpd
aminobenzoic acid;
secondary amino compound
membrane transport modulator
nifedipineNifedipine: A potent vasodilator agent with calcium antagonistic action. It is a useful anti-anginal agent that also lowers blood pressure.C-nitro compound;
dihydropyridine;
methyl ester
calcium channel blocker;
human metabolite;
tocolytic agent;
vasodilator agent
ro 31-8220Ro 31-8220: a protein kinase C inhibitorimidothiocarbamic ester;
indoles;
maleimides
EC 2.7.11.13 (protein kinase C) inhibitor
fenofibratebenzochromenone;
delta-lactone;
naphtho-alpha-pyrone
platelet aggregation inhibitor;
Sir2 inhibitor
suraminsuramin : A member of the class of phenylureas that is urea in which each of the amino groups has been substituted by a 3-({2-methyl-5-[(4,6,8-trisulfo-1-naphthyl)carbamoyl]phenyl}carbamoyl)phenyl group. An activator of both the rabbit skeletal muscle RyR1 and sheep cardiac RyR2 isoform ryanodine receptor channels, it has been used for the treatment of human African trypanosomiasis for over 100 years.

Suramin: A polyanionic compound with an unknown mechanism of action. It is used parenterally in the treatment of African trypanosomiasis and it has been used clinically with diethylcarbamazine to kill the adult Onchocerca. (From AMA Drug Evaluations Annual, 1992, p1643) It has also been shown to have potent antineoplastic properties.
naphthalenesulfonic acid;
phenylureas;
secondary carboxamide
angiogenesis inhibitor;
antinematodal drug;
antineoplastic agent;
apoptosis inhibitor;
EC 2.7.11.13 (protein kinase C) inhibitor;
GABA antagonist;
GABA-gated chloride channel antagonist;
purinergic receptor P2 antagonist;
ryanodine receptor agonist;
trypanocidal drug
tetraethylammoniumTetraethylammonium: A potassium-selective ion channel blocker. (From J Gen Phys 1994;104(1):173-90)quaternary ammonium ion
suramin sodiumsuramin sodium : An organic sodium salt that is the hexasodium salt of suramin. It is an FDA approved drug for African sleeping sickness and river blindness.organic sodium saltangiogenesis inhibitor;
antinematodal drug;
antineoplastic agent;
apoptosis inhibitor;
EC 2.7.11.13 (protein kinase C) inhibitor;
GABA antagonist;
GABA-gated chloride channel antagonist;
purinergic receptor P2 antagonist;
ryanodine receptor agonist;
trypanocidal drug
diltiazemdiltiazem : A 5-[2-(dimethylamino)ethyl]-2-(4-methoxyphenyl)-4-oxo-2,3,4,5-tetrahydro-1,5-benzothiazepin-3-yl acetate in which both stereocentres have S configuration. A calcium-channel blocker and vasodilator, it is used as the hydrochloride in the management of angina pectoris and hypertension.

Diltiazem: A benzothiazepine derivative with vasodilating action due to its antagonism of the actions of CALCIUM ion on membrane functions.
5-[2-(dimethylamino)ethyl]-2-(4-methoxyphenyl)-4-oxo-2,3,4,5-tetrahydro-1,5-benzothiazepin-3-yl acetateantihypertensive agent;
calcium channel blocker;
vasodilator agent
toxoflavintoxoflavin : A pyrimidotriazine that is 1,6-dimethyl-1,5,6,7-tetrahydropyrimido[5,4-e][1,2,4]triazine with oxo groups at positions 5 and 7.

toxoflavin: azapteridine antibiotic; structure
carbonyl compound;
pyrimidotriazine
antibacterial agent;
antineoplastic agent;
apoptosis inducer;
bacterial metabolite;
toxin;
virulence factor;
Wnt signalling inhibitor
cortisone11-oxo steroid;
17alpha-hydroxy steroid;
20-oxo steroid;
21-hydroxy steroid;
3-oxo-Delta(4) steroid;
C21-steroid;
glucocorticoid;
primary alpha-hydroxy ketone;
tertiary alpha-hydroxy ketone
human metabolite;
mouse metabolite
paullonepaullone : An indolobenzazepine that is 5,6,7,12-tetrahydroindolo[3,2-d][1]benzazepine carrying an oxo substituent at position 6.

paullone: structure in first source
indolobenzazepine;
lactam
EC 2.7.11.22 (cyclin-dependent kinase) inhibitor;
EC 2.7.11.26 (tau-protein kinase) inhibitor
hyperforinhyperforin : A cyclic terpene ketone that is a prenylated carbobicyclic acylphloroglucinol derivative produced by St. John's Wort, Hypericum perforatum.

hyperforin: a prenylated acylphloroglucinol derivative; antibiotic component of novoimanine; psychoactive agent in St. John's wort; Russian; structure;
resveratroltrans-resveratrol : A resveratrol in which the double bond has E configuration.resveratrolantioxidant;
phytoalexin;
plant metabolite;
quorum sensing inhibitor;
radical scavenger
3-(1-azepanylsulfonyl)-n-(3-bromphenyl)benzamide3-(1-azepanylsulfonyl)-N-(3-bromphenyl)benzamide: a sirtuin 2 inhibitor; structure in first source
capsaicinALGRX-4975: an injectable capsaicin (TRPV1 receptor agonist) formulation for longlasting pain relief

capsaicinoid : A family of aromatic fatty amides produced as secondary metabolites by chilli peppers.
capsaicinoidnon-narcotic analgesic;
TRPV1 agonist;
voltage-gated sodium channel blocker
1,4-bis[2-(4-hydroxyphenyl)ethylamino]anthracene-9,10-dioneanthraquinone
sirtinolaldimine;
benzamides;
naphthols
anti-inflammatory agent;
EC 3.5.1.98 (histone deacetylase) inhibitor;
Sir2 inhibitor
cambinolcambinol: inhibitor of human silent information regulator 2 enzymes; structure in first source
(4-chlorophenyl)-[4-(8-nitro-5-quinolinyl)-1-piperazinyl]methanoneN-arylpiperazine
ex 5276-chloro-2,3,4,9-tetrahydro-1H-carbazole-1-carboxamide : A member of the class of carbazoles that is 2,3,4,9-tetrahydro-1H-carbazole which is substituted at position 1 by an aminocarbohyl group and at position 6 by a chlorine.

6-chloro-2,3,4,9-tetrahydro-1H-carbazole-1-carboxamide: structure in first source
carbazoles;
monocarboxylic acid amide;
organochlorine compound
su 11248monocarboxylic acid amide;
pyrroles
angiogenesis inhibitor;
antineoplastic agent;
EC 2.7.10.1 (receptor protein-tyrosine kinase) inhibitor;
immunomodulator;
neuroprotective agent;
vascular endothelial growth factor receptor antagonist
clathrodinclathrodin: structure given in first source; isolated from marine sponges of the genus Agelas
oroidinoroidin: from marine sponges of the genus Agelas; structure in first sourcepyrroles;
secondary carboxamide
metabolite
hymenidinhymenidin: serotonergic receptor antagonist from Okinawan marine sponge Hymeniacidon; structure given in first source
panobinostatpanobinostat : A hydroxamic acid obtained by formal condensation of the carboxy group of (2E)-3-[4-({[2-(2-methylindol-3-yl)ethyl]amino}methyl)phenyl]prop-2-enoic acid with the amino group of hydroxylamine. A histone deacetylase inhibitor used (as its lactate salt) in combination with bortezomib and dexamethasone for the treatment of multiple myeloma.

Panobinostat: An indole and hydroxamic acid derivative that acts as a HISTONE DEACETYLASE inhibitor. It is used as an antineoplastic agent in combination with BORTEZOMIB and DEXAMETHASONE for the treatment of MULTIPLE MYELOMA.
cinnamamides;
hydroxamic acid;
methylindole;
secondary amino compound
angiogenesis modulating agent;
antineoplastic agent;
EC 3.5.1.98 (histone deacetylase) inhibitor
oblongifolin coblongifolin C: has antineoplastic activity; isolated from Garcinia yunnanensis; structure in first source
quisinostatindoles
srt1460SRT1460: small molecule activator of SIRT1 as therapeutics for the treatment of type 2 diabetes; structure in first source
srt1720
srt2183SRT2183: small molecule activator of SIRT1 as therapeutics for the treatment of type 2 diabetes; structure in first source
tenovin-6tenovin-6 : A monocarboxylic acid amide obtained by formal condensation of the carboxy group of 5-(dimethylamino)pentanoic acid with the aromatic amino group of N-[(4-aminophenyl)carbamothioyl]-4-tert-butylbenzamide.monocarboxylic acid amide;
tertiary amino compound;
thioureas
antineoplastic agent;
p53 activator;
Sir2 inhibitor
tat-nr2b9cTat-NR2B9c: a synthetic peptide consisting of the C-terminal 9 amino acids of the NR2B subunit of the NMDA receptor fused to the cell membrane protein transduction domain of the HIV-1-Tat protein
acy-1215ricolinostat: an HDAC6 inhibitor; structure in first sourcepyrimidinecarboxylic acid
aristoforinAristoforin: derivative of hyperforin, is a potent anticancer agent; structure in first source
n-(3-((2-hydroxynaphthalen-1-ylmethylene)amino)phenyl)-2-phenylpropionamide