Q9LD83 · SLAC1_ARATH
- ProteinGuard cell S-type anion channel SLAC1
- GeneSLAC1
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids556 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Slow, weak voltage-dependent S-type anion efflux channel involved in maintenance of anion homeostasis. Cl- efflux through SLAC1 causes membrane depolarization, which activates outward-rectifying K1 channels, leading to KCl and water efflux to reduce turgor further and cause stomatal closure, that reduces water loss and promotes leaf turgor. Essential for stomatal closure in response to CO2, abscisic acid (ABA), ozone O3, light/dark transitions, humidity change, calcium ions, hydrogen peroxide H2O2, reactive oxygen species (ROS), and nitric oxide. Binds to the highly selective inward-rectifying potassium channels KAT1 and AKT2, and inhibits their activities. Functions as an essential negative regulator of inward potassium channels in guard cells. Essential for the efficient stomatal closure and opening in guard cells (PubMed:27002025).
Involved in the local and/or systemic stomatal responses (e.g. stomatal closure) to light stress (PubMed:29463779).
Involved in the local and/or systemic stomatal responses (e.g. stomatal closure) to light stress (PubMed:29463779).
Activity regulation
Activated by GHR1-mediated phosphorylation which is negatively regulated by ABI2 but not ABI1 (PubMed:22730405).
Activation by SRK2E/OST1 and GHR1 is repressed by HT1 (PubMed:27694184).
Activation by SRK2E/OST1 and GHR1 is repressed by HT1 (PubMed:27694184).
Features
Showing features for site.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Site | 450 | Important for channel gating | |||
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | membrane | |
Cellular Component | plasma membrane | |
Molecular Function | monoatomic anion transmembrane transporter activity | |
Molecular Function | protein kinase binding | |
Molecular Function | protein phosphatase binding | |
Molecular Function | voltage-gated monoatomic anion channel activity | |
Biological Process | abscisic acid-activated signaling pathway | |
Biological Process | inorganic anion transport | |
Biological Process | intracellular monoatomic ion homeostasis | |
Biological Process | monoatomic anion transport | |
Biological Process | multicellular organismal-level water homeostasis | |
Biological Process | organic anion transport | |
Biological Process | regulation of stomatal closure | |
Biological Process | regulation of stomatal opening | |
Biological Process | response to abscisic acid | |
Biological Process | response to carbon dioxide | |
Biological Process | response to humidity | |
Biological Process | response to light stimulus | |
Biological Process | response to ozone | |
Biological Process | stomatal closure | |
Biological Process | stomatal movement |
Keywords
- Biological process
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameGuard cell S-type anion channel SLAC1
- Alternative names
Gene names
Organism names
- Strain
- Taxonomic lineageEukaryota > Viridiplantae > Streptophyta > Embryophyta > Tracheophyta > Spermatophyta > Magnoliopsida > eudicotyledons > Gunneridae > Pentapetalae > rosids > malvids > Brassicales > Brassicaceae > Camelineae > Arabidopsis
Accessions
- Primary accessionQ9LD83
Proteomes
Organism-specific databases
Genome annotation databases
Subcellular Location
UniProt Annotation
GO Annotation
Cell membrane ; Multi-pass membrane protein
Features
Showing features for topological domain, transmembrane.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Topological domain | 1-189 | Cytoplasmic | |||
Transmembrane | 190-210 | Helical | |||
Topological domain | 211-216 | Extracellular | |||
Transmembrane | 217-237 | Helical | |||
Topological domain | 238-265 | Cytoplasmic | |||
Transmembrane | 266-286 | Helical | |||
Topological domain | 287-295 | Extracellular | |||
Transmembrane | 296-316 | Helical | |||
Topological domain | 317-325 | Cytoplasmic | |||
Transmembrane | 326-346 | Helical | |||
Topological domain | 347-352 | Extracellular | |||
Transmembrane | 353-373 | Helical | |||
Topological domain | 374-388 | Cytoplasmic | |||
Transmembrane | 389-409 | Helical | |||
Topological domain | 410-418 | Extracellular | |||
Transmembrane | 419-439 | Helical | |||
Topological domain | 440 | Cytoplasmic | |||
Transmembrane | 441-463 | Helical | |||
Topological domain | 464-479 | Extracellular | |||
Transmembrane | 480-500 | Helical | |||
Topological domain | 501-556 | Cytoplasmic | |||
Keywords
- Cellular component
Phenotypes & Variants
Disruption phenotype
Constitutively higher stomatal conductance with over-accumulation of the osmoregulatory anions in guard cell. Impaired slow (S-type) anion channel currents that are activated by cytosolic calcium ions and abscisic acid (ABA) (normally leading to a decrease in stomatal conductance). Higher sensitivity to ozone. Increased water loss associated with a constitutive stomatal opening phenotype. Reduced circadian leaf turgor changes.
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Mutagenesis | 38 | In slac1-6; normal ozone-triggered rapid transient decrease (RTD) in stomatal conductance. | |||
Mutagenesis | 120 | In slac1-7; impaired ozonetriggered rapid transient decrease (RTD) in stomatal conductance. | |||
Mutagenesis | 146 | In slac1-8; impaired ozone-triggered rapid transient decrease (RTD) in stomatal conductance. | |||
Mutagenesis | 194 | In slac1-2; impaired anion transport activity, strong insensitivity to abscisic acid (ABA), altered CO2-dependent leaf temperature change and stomatal closure, reduced sensitivity to darkness, and defective regulation of transpiration in response to drought stress. Impaired anion transport activity; when associated with A-450. | |||
Mutagenesis | 450 | Enhanced and constitutive anion transport activity. Impaired anion transport activity; when associated with D-194. | |||
Mutagenesis | 450 | Enhanced and constitutive anion transport activity. | |||
Mutagenesis | 450 | Impaired anion transport activity. | |||
Mutagenesis | 456 | In slac1-1; reduced slow (S-type) anion channel currents, and increased water loss due to impaired stomatal closure. | |||
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 22 variants from UniProt as well as other sources including ClinVar and dbSNP.
PTM/Processing
Features
Showing features for chain, modified residue.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Chain | PRO_0000404259 | 1-556 | Guard cell S-type anion channel SLAC1 | ||
Modified residue | 59 | Phosphoserine; by SRK2E | |||
Modified residue | 86 | Phosphoserine; by SRK2E | |||
Modified residue | 113 | Phosphoserine; by SRK2E | |||
Modified residue | 120 | Phosphoserine; by SRK2E | |||
Modified residue | 146 | Phosphoserine | |||
Post-translational modification
Phosphorylation by SRK2E, especially on Ser-120, activates the channel. Also phosphorylated and activated by CPK21 and CPK23. Abscisic acid (ABA) promotes phosphorylation. This phosphorylation is inhibited by ABI1. Phosphorylated and activated by GHR1; this phosphorylation is repressed by ABI2 but not ABI1 (PubMed:22730405).
Phosphorylated by HT1 on N-terminus but not C-terminus (PubMed:27694184).
Phosphorylated by HT1 on N-terminus but not C-terminus (PubMed:27694184).
Keywords
- PTM
Proteomic databases
PTM databases
Expression
Tissue specificity
Preferentially expressed in guard cells. Also detected in the vascular strands close to the leaf margins.
Induction
By drought stress in guard cells.
Gene expression databases
Interaction
Subunit
Homotrimer. Interacts with SRK2E, CPK6, CPK21, CPK23 and PP2CA. The channel is inactivated upon PP2CA and ABI1 binding. Interacts with KAT1, KAT2, KAT3/KC1 and AKT2 (PubMed:27002025).
Interacts with GHR1 (PubMed:22730405, PubMed:30361234).
Interacts with GHR1 (PubMed:22730405, PubMed:30361234).
Binary interactions
Type | Entry 1 | Entry 2 | Number of experiments | IntAct | |
---|---|---|---|---|---|
BINARY | Q9LD83 | CPK21 Q9ZSA2 | 2 | EBI-11174918, EBI-8519603 | |
BINARY | Q9LD83 | CPK23 Q9M101 | 4 | EBI-11174918, EBI-15847592 | |
BINARY | Q9LD83 | SRK2E Q940H6 | 8 | EBI-11174918, EBI-782514 |
Protein-protein interaction databases
Structure
Family & Domains
Features
Showing features for region, coiled coil, compositional bias.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Region | 1-103 | Disordered | |||
Coiled coil | 10-36 | ||||
Compositional bias | 27-41 | Polar residues | |||
Compositional bias | 67-82 | Basic and acidic residues | |||
Sequence similarities
Belongs to the SLAC1 S-type anion channel family.
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length556
- Mass (Da)63,235
- Last updated2000-10-01 v1
- ChecksumE2E310F026EE0C01
Features
Showing features for compositional bias.
Type | ID | Position(s) | Description | ||
---|---|---|---|---|---|
Compositional bias | 27-41 | Polar residues | |||
Compositional bias | 67-82 | Basic and acidic residues | |||
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AC025416 EMBL· GenBank· DDBJ | AAF79652.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AC025417 EMBL· GenBank· DDBJ | AAF88102.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
CP002684 EMBL· GenBank· DDBJ | AEE28888.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
AF424557 EMBL· GenBank· DDBJ | AAL11551.1 EMBL· GenBank· DDBJ | mRNA | ||
BT002640 EMBL· GenBank· DDBJ | AAO11556.1 EMBL· GenBank· DDBJ | mRNA |