Q92952 · KCNN1_HUMAN
- ProteinSmall conductance calcium-activated potassium channel protein 1
- GeneKCNN1
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids543 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Small conductance calcium-activated potassium channel that mediates the voltage-independent transmembrane transfer of potassium across the cell membrane through a constitutive interaction with calmodulin which binds the intracellular calcium allowing its opening (PubMed:17142458, PubMed:8781233, PubMed:9287325).
The current is characterized by a voltage-independent activation, an intracellular calcium concentration increase-dependent activation and a single-channel conductance of about 3 picosiemens (PubMed:8781233).
Also presents an inwardly rectifying current, thus reducing its already small outward conductance of potassium ions, which is particularly the case when the membrane potential displays positive values, above + 20 mV (Probable). Activation is followed by membrane hyperpolarization (By similarity).
Thought to regulate neuronal excitability by contributing to the slow component of synaptic afterhyperpolarization (By similarity).
The current is characterized by a voltage-independent activation, an intracellular calcium concentration increase-dependent activation and a single-channel conductance of about 3 picosiemens (PubMed:8781233).
Also presents an inwardly rectifying current, thus reducing its already small outward conductance of potassium ions, which is particularly the case when the membrane potential displays positive values, above + 20 mV (Probable). Activation is followed by membrane hyperpolarization (By similarity).
Thought to regulate neuronal excitability by contributing to the slow component of synaptic afterhyperpolarization (By similarity).
Catalytic activity
- K+(in) = K+(out)
Activity regulation
Inhibited by bee venom neurotoxin apamin (PubMed:17142458, PubMed:9287325).
Inhibited by d-tubocurarine and tetraethylammonium (TEA) (PubMed:17142458, PubMed:9287325).
Inhibited by d-tubocurarine and tetraethylammonium (TEA) (PubMed:17142458, PubMed:9287325).
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | neuron projection | |
Cellular Component | neuronal cell body | |
Cellular Component | plasma membrane | |
Cellular Component | synapse | |
Cellular Component | voltage-gated potassium channel complex | |
Molecular Function | calcium-activated potassium channel activity | |
Molecular Function | calmodulin binding | |
Molecular Function | inward rectifier potassium channel activity | |
Molecular Function | small conductance calcium-activated potassium channel activity | |
Biological Process | chemical synaptic transmission | |
Biological Process | potassium ion transmembrane transport | |
Biological Process | potassium ion transport |
Keywords
- Molecular function
- Biological process
Enzyme and pathway databases
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameSmall conductance calcium-activated potassium channel protein 1
- Short namesSK1 ; SKCa 1; SKCa1; hSK1
- Alternative names
Gene names
Organism names
- Organism
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Hominidae > Homo
Accessions
- Primary accessionQ92952
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
UniProt Annotation
GO Annotation
Membrane ; Multi-pass membrane protein
Features
Showing features for transmembrane, intramembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Transmembrane | 111-131 | Helical; Name=Segment S1 | ||||
Sequence: LIFGMFGIVVMVTETELSWGV | ||||||
Transmembrane | 140-160 | Helical; Name=Segment S2 | ||||
Sequence: FALKCLISLSTAILLGLVVLY | ||||||
Transmembrane | 179-199 | Helical; Name=Segment S3 | ||||
Sequence: IAMTCERVFLISLELAVCAIH | ||||||
Transmembrane | 228-248 | Helical; Name=Segment S4 | ||||
Sequence: VLLSIPMFLRLYLLGRVMLLH | ||||||
Transmembrane | 277-297 | Helical; Name=Segment S5 | ||||
Sequence: LMTICPGTVLLVFSISSWIIA | ||||||
Intramembrane | 317-337 | Pore-forming; Name=Segment H5 | ||||
Sequence: FLGAMWLISITFLSIGYGDMV | ||||||
Transmembrane | 346-366 | Helical; Name=Segment S6 | ||||
Sequence: VCLLTGIMGAGCTALVVAVVA |
Keywords
- Cellular component
Disease & Variants
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Mutagenesis | 216 | Significantly increased inhibition by apamin (IC50=167 pM). No effect on inhibition by d-tubocurarine and tetraethylammonium (TEA). Significant increase in inhibition by apamin (IC50=26 pM); when associated with Q-310, D-312 and N-339. | ||||
Sequence: T → S | ||||||
Mutagenesis | 310 | Loss of inhibition by apamin. No effect on inhibition by d-tubocurarine. Increased inhibition by apamin; when associated with D-312. Significant increase in inhibition by apamin (IC50=366 pM); when associated with D-312 and N-339. Significant increase in inhibition by apamin (IC50=26 pM); when associated with S-216, D-312 and N-339. | ||||
Sequence: K → Q | ||||||
Mutagenesis | 312 | Increased inhibition by apamin or d-tubocurarine (IC50=62.6 uM). Additive increase in inhibition by apamin or d-tubocurarine (IC50=6.3 uM); when associated with N-339. Additive increase in inhibition by apamin; when associated with Q-310. Significant increase in inhibition by apamin (IC50=366 pM); when associated with Q-310 and N-339. Significant increase in inhibition by apamin (IC50=26 pM); when associated with S-216, Q-310 and N-339. | ||||
Sequence: E → D | ||||||
Mutagenesis | 332-334 | Impairs small conductance calcium-activated potassium channel activity of KCNN2. | ||||
Sequence: GYG → AAA | ||||||
Mutagenesis | 337 | Increased inhibition by tetraethylammonium (TEA). | ||||
Sequence: V → Y | ||||||
Mutagenesis | 339 | Increased inhibition by apamin or d-tubocurarine (IC50=11.1 uM). Additive increase in inhibition by apamin or d-tubocurarine (IC50=6.3 uM); when associated with D-312. Significant increase in inhibition by apamin (IC50=366 pM); when associated with Q-310 and D-312. Significant increase in inhibition by apamin (IC50=26 pM); when associated with S-216, Q-310 and D-312. | ||||
Sequence: H → N |
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 551 variants from UniProt as well as other sources including ClinVar and dbSNP.
Organism-specific databases
Miscellaneous
Chemistry
Genetic variation databases
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000155007 | 1-543 | Small conductance calcium-activated potassium channel protein 1 | |||
Sequence: MNSHSYNGSVGRPLGSGPGALGRDPPDPEAGHPPQPPHSPGLQVVVAKSEPARPSPGSPRGQPQDQDDDEDDEEDEAGRQRASGKPSNVGHRLGHRRALFEKRKRLSDYALIFGMFGIVVMVTETELSWGVYTKESLYSFALKCLISLSTAILLGLVVLYHAREIQLFMVDNGADDWRIAMTCERVFLISLELAVCAIHPVPGHYRFTWTARLAFTYAPSVAEADVDVLLSIPMFLRLYLLGRVMLLHSKIFTDASSRSIGALNKITFNTRFVMKTLMTICPGTVLLVFSISSWIIAAWTVRVCERYHDKQEVTSNFLGAMWLISITFLSIGYGDMVPHTYCGKGVCLLTGIMGAGCTALVVAVVARKLELTKAEKHVHNFMMDTQLTKRVKNAAANVLRETWLIYKHTRLVKKPDQARVRKHQRKFLQAIHQAQKLRSVKIEQGKLNDQANTLTDLAKTQTVMYDLVSELHAQHEELEARLATLESRLDALGASLQALPGLIAQAIRPPPPPLPPRPGPGPQDQAARSSPCRWTPVAPSDCG |
Proteomic databases
PTM databases
Expression
Interaction
Subunit
Homodimer (PubMed:20689065).
Heteromultimer with KCNN2 and KCNN3 (PubMed:20689065, PubMed:9287325).
The complex is composed of 4 channel subunits each of which binds to a calmodulin subunit which regulates the channel activity through calcium-binding (By similarity).
Interacts with calmodulin (By similarity).
Heteromultimer with KCNN2 and KCNN3 (PubMed:20689065, PubMed:9287325).
The complex is composed of 4 channel subunits each of which binds to a calmodulin subunit which regulates the channel activity through calcium-binding (By similarity).
Interacts with calmodulin (By similarity).
Protein-protein interaction databases
Chemistry
Miscellaneous
Structure
Family & Domains
Features
Showing features for region, compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 1-92 | Disordered | ||||
Sequence: MNSHSYNGSVGRPLGSGPGALGRDPPDPEAGHPPQPPHSPGLQVVVAKSEPARPSPGSPRGQPQDQDDDEDDEEDEAGRQRASGKPSNVGHR | ||||||
Region | 384-463 | Calmodulin-binding | ||||
Sequence: DTQLTKRVKNAAANVLRETWLIYKHTRLVKKPDQARVRKHQRKFLQAIHQAQKLRSVKIEQGKLNDQANTLTDLAKTQTV | ||||||
Compositional bias | 505-522 | Pro residues | ||||
Sequence: QAIRPPPPPLPPRPGPGP | ||||||
Region | 505-543 | Disordered | ||||
Sequence: QAIRPPPPPLPPRPGPGPQDQAARSSPCRWTPVAPSDCG |
Domain
The coiled-coil domaim mediates heteromeic assembly.
Sequence similarities
Belongs to the potassium channel KCNN family. KCa2.1/KCNN1 subfamily.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence & Isoform
- Sequence statusComplete
This entry describes 2 isoforms produced by Alternative splicing.
Q92952-1
This isoform has been chosen as the canonical sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
- Name1
- Length543
- Mass (Da)59,987
- Last updated2007-01-23 v2
- Checksum13EFF47C263BCB11
Q92952-2
- Name2
- Differences from canonical
- 1-1: M → MPGPRAACSEPNPCTQVVM
Computationally mapped potential isoform sequences
There are 6 potential isoforms mapped to this entry
Entry | Entry name | Gene name | Length | ||
---|---|---|---|---|---|
A0A804HIW7 | A0A804HIW7_HUMAN | KCNN1 | 546 | ||
A0A804HIF9 | A0A804HIF9_HUMAN | KCNN1 | 540 | ||
A0A804HIJ6 | A0A804HIJ6_HUMAN | KCNN1 | 434 | ||
V9GYV2 | V9GYV2_HUMAN | KCNN1 | 390 | ||
A0A804HK94 | A0A804HK94_HUMAN | KCNN1 | 428 | ||
A0A087X2E7 | A0A087X2E7_HUMAN | KCNN1 | 543 |
Features
Showing features for alternative sequence, compositional bias, sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Alternative sequence | VSP_022501 | 1 | in isoform 2 | |||
Sequence: M → MPGPRAACSEPNPCTQVVM | ||||||
Compositional bias | 505-522 | Pro residues | ||||
Sequence: QAIRPPPPPLPPRPGPGP | ||||||
Sequence conflict | 513-542 | in Ref. 3; BAD86831 | ||||
Sequence: PLPPRPGPGPQDQAARSSPCRWTPVAPSDC → RLPRQRAGLDH |
Keywords
- Coding sequence diversity
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
U69883 EMBL· GenBank· DDBJ | AAB09562.1 EMBL· GenBank· DDBJ | mRNA | ||
AF131948 EMBL· GenBank· DDBJ | AAD37507.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AF131940 EMBL· GenBank· DDBJ | AAD37507.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AF131941 EMBL· GenBank· DDBJ | AAD37507.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AF131942 EMBL· GenBank· DDBJ | AAD37507.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AF131943 EMBL· GenBank· DDBJ | AAD37507.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AF131944 EMBL· GenBank· DDBJ | AAD37507.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AF131945 EMBL· GenBank· DDBJ | AAD37507.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AF131946 EMBL· GenBank· DDBJ | AAD37507.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AF131947 EMBL· GenBank· DDBJ | AAD37507.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AB198191 EMBL· GenBank· DDBJ | BAD86831.1 EMBL· GenBank· DDBJ | mRNA | ||
BC075037 EMBL· GenBank· DDBJ | AAH75037.3 EMBL· GenBank· DDBJ | mRNA |