SynDB Home Page
SynDB Home Page

blue bulletSynDB protein details  

Parse error: syntax error, unexpected T_VARIABLE in /home/kongl/syndb/www/sdb_nats.php on line 52
0HCN4_HUMAN*   SwissProt (?) | Description Local Annotation Link Reference
General Information
DescriptionPotassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 4.
SpeciesHomo sapiens (NCBI taxonomy ID: 9606)
GO0005261 cation channel activity (TAS)
0006812 cation transport (TAS)
0008015 circulation (NAS)
0006936 muscle contraction (TAS)

Warning: fopen(/home/kongl/syndb/www/temp/ [function.fopen]: failed to open stream: Permission denied in /home/kongl/syndb/www/sdb_pro.php on line 269

Warning: fwrite(): supplied argument is not a valid stream resource in /home/kongl/syndb/www/sdb_pro.php on line 270

Warning: fwrite(): supplied argument is not a valid stream resource in /home/kongl/syndb/www/sdb_pro.php on line 271

Warning: fwrite(): supplied argument is not a valid stream resource in /home/kongl/syndb/www/sdb_pro.php on line 272

Warning: fwrite(): supplied argument is not a valid stream resource in /home/kongl/syndb/www/sdb_pro.php on line 273

Warning: fwrite(): supplied argument is not a valid stream resource in /home/kongl/syndb/www/sdb_pro.php on line 274

Warning: fwrite(): supplied argument is not a valid stream resource in /home/kongl/syndb/www/sdb_pro.php on line 299

Warning: fclose(): supplied argument is not a valid stream resource in /home/kongl/syndb/www/sdb_pro.php on line 300
schematic display of those terms with internal associations, click the node and browse the corresponding GO term
Domain Architecture (Details)
InterPro domains assigned to SynO:
Potassium channels are the most diverse group of the ion channel family. They are important in shaping the action potential.nd in neuronal excitability and plasticity . The potassium channel family iscomposed of several functionally distinct isoforms.hich can be broadlyseparated into 2 groups : the practically non-inactivating delayed group and the rapidly inactivating transient group.These are all highly similar proteins.ith only small amino acidchanges causing the diversity of the voltage-dependent gating mechanism.hannel conductance and toxin binding properties. Each type of K+ channel is activated by different signals and conditions depending on their type of regulation: some open in response to depolarisation of the plasma membrane; others in response to hyperpolarisation or an increase in intracellular calcium concentration; some can be regulated by binding of a transmitter.ogether with intracellular kinases; and others are regulated by GTP-binding proteins orother second messengers . In eukaryotic cells.+ channelsare involved in neural signalling and generation of the cardiac rhythm.ct as effectors in signal transduction pathways involving G protein-coupled receptors (GPCRs) and may have a role in target cell lysis by cytotoxic T-lymphocytes . In prokaryotic cells.hey play a role in themaintenance of ionic homeostasis . All K+ channels discovered so far possess a core of alpha subunits.ach comprising either one or two copies of a highly conserved pore loop domain (P-domain). The P-domain contains the sequence (T/SxxTxGxG).hich hasbeen termed the K+ selectivity sequence.In families that contain one P-domain.our subunits assemble to form a selective pathway for K+ across the membrane.However.t remains unclear how the 2 P-domain subunits assemble to form a selective pore. The functional diversity of these families can arise through homo- or hetero-associations of alpha subunits or association with auxiliary cytoplasmic beta subunits. K+ channel subunits containing one pore domain can be assigned into one of two superfamilies: those that possess six transmembrane (TM) domains and those that possess only two TM domains. The six TM domain superfamily can be further subdivided into conserved gene families: the voltage-gated (Kv) channels; the KCNQ channels (originally known as KvLQT channels); the EAG-like K+ channels; and three types of calcium (Ca)-activated K+ channels (BK.K and SK). The 2TM domain family comprises inward-rectifying K+ channels. In are K+ channel alpha-subunits that possess two P-domains. These are usually highly regulated K+ selective leak channels.The first EAG K+ channel was identified in Drosophila melanogaster.ollowing a screen for mutations giving rise to behavioural abnormalities. Disruption of the Eag gene caused an behaviour. Subsequent studies have revealed a conserved multi-gene family of EAG-like K+ channels.hich are present in human and many other species. Based on the varying functional properties of the channels.he family has been divided into 3 subfamilies: EAG.LK and ERG. Interestingly.aenorhabditis elegans appears to lack the ELK type .
  IPR003938:EAG/ELK/ERG potassium channel
InterPro domains unassigned to SynO:
This metazoan domain is found to the N terminus of in voltage- and cyclic nucleotide-gated K/Na ion channels.
  IPR013621:Ion transport N-terminal
This group of proteins is found in sodium.otassium.nd calcium ion channels proteins. The proteins have 6 transmembrane helices in which the last two helices flank a loop which determines ion selectivity. In some Na channels proteins the domain is repeated four times.hereas in others (e.g. K channels) the protein forms a tetramer in the membrane. A bacterial structure of the protein is known for the last two helices but is not included in the Pfam family due to it lacking the first four helices.
  IPR005821:Ion transport
Proteins that bind cyclic nucleotides (cAMP or cGMP) share a structural domain of about 120 residues . The best studied of these proteins is the prokaryotic catabolite gene activator (alsoknown as the cAMP receptor protein) (gene crp) where such a domain is known to be composed of three alpha-helices anda distinctive eight-stranded.ntiparallel beta-barrel structure. There are six invariant amino acids in this domain.hree of which are glycine residues that are thought to be essential for maintenance of the structural integrity ofthe beta-barrel. cAMP- and cGMP-dependent protein kinases (cAPK and cGPK) contain two tandem copies of the cyclicnucleotide-binding domain. The cAPKs are composed of two different subunits. catalytic chain and a regulatory chain.hich contains both copies of the domain. The cGPKs are single chain enzymes that include the two copies of the domainin their N-terminal section. Vertebrate cyclic nucleotide-gated ion-channels also contain this domain. Two suchcations channels have been fully is found in rod cells where it plays a role in visual signaltransduction.
  IPR000595:Cyclic nucleotide-binding
SequencesProtein: HCN4_HUMAN (1203 aa)
mRNA: NM_005477
Local Annotation
Synapse Ontology
A process that increases long-term neuronal synaptic plasticity, the ability of neuronal synapses to change long-term as circumstances require. Long-term neuronal synaptic plasticity generally involves increase or decrease in actual synapse numbers.
sdb:0039 positive regulation of long-term neuronal synaptic plasticity  (Evidence:keywords,domains)
A process that increases short-term neuronal synaptic plasticity, the ability of neuronal synapses to change in the short-term as circumstances require. Short-term neuronal synaptic plasticity generally involves increasing or decreasing synaptic sensitivity.
sdb:0043 positive regulation of short-term neuronal synaptic plasticity  (Evidence:keywords,domains)
this kind of receptor usually locates at the postsynaptic plasma membranous region.
sdb:0109 ionotropic receptor  (Evidence:keywords,domains)
sdb:0219 GPCR mediated signaling  (Evidence:keywords,domains)
LTP that is not dependent on the function of NMDA receptor.
sdb:0255 NMDA Receptor-independent LTP  (Evidence:keywords,domains)
sdb:0265 cAMP mediated STP  (Evidence:keywords,domains)
K channel plays an important role in the course of action potential
sdb:0286 K channel  (Evidence:keywords,domains)
Na channel plays an important role in the course of action potential.
sdb:0287 Na channel  (Evidence:keywords,domains)
all kinds of ion channels that play their roles in the synaptic activity.
sdb:0308 ion channels and receptors  (Evidence:keywords,domains)
KO assignmentK04957
  Level 3 annotation:
    hyperpolarization activated cyclic nucleotide-gated potassium channel 4
  Level 2 annotation:
    Ion channels
Loci Structure (Details)Loci index, Chromosomal location, Length, Possible relational loci clusterExon1: 786 residues, 71400987-71403343Exon2: 57 residues, 71403482-71403647Exon3: 82 residues, 71404348-71404589Exon4: 51 residues, 71404691-71404838Exon5: 75 residues, 71408966-71409185Exon6: 56 residues, 71411524-71411686Exon7: 143 residues, 71422778-71423202Exon8: 452 residues, 71446879-71448230Exon9: 2 residues, -Jump to HCN4_HUMAN  
Tune and view alternative isoforms
Loci Cluster (Details)Loci: 4179 71400987-71448230 ~-47K 12681(HCN4)(-)Loci: 2898 71131927-71382835 ~-251K 12680(NEO1)(+)Link out to UCSC