Q9LD83 · SLAC1_ARATH

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).

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).

Features

Showing features for site.

155650100150200250300350400450500550
TypeIDPosition(s)Description
Site450Important for channel gating

GO annotations

AspectTerm
Cellular Componentmembrane
Cellular Componentplasma membrane
Molecular Functionmonoatomic anion transmembrane transporter activity
Molecular Functionprotein kinase binding
Molecular Functionprotein phosphatase binding
Molecular Functionvoltage-gated monoatomic anion channel activity
Biological Processabscisic acid-activated signaling pathway
Biological Processinorganic anion transport
Biological Processintracellular monoatomic ion homeostasis
Biological Processmonoatomic anion transport
Biological Processmulticellular organismal-level water homeostasis
Biological Processorganic anion transport
Biological Processregulation of stomatal closure
Biological Processregulation of stomatal opening
Biological Processresponse to abscisic acid
Biological Processresponse to carbon dioxide
Biological Processresponse to humidity
Biological Processresponse to light stimulus
Biological Processresponse to ozone
Biological Processstomatal closure
Biological Processstomatal movement

Keywords

Protein family/group databases

    • 2.A.16.5.1the telurite-resistance/dicarboxylate transporter (tdt) family

Names & Taxonomy

Protein names

  • Recommended name
    Guard cell S-type anion channel SLAC1
  • Alternative names
    • Protein CARBON DIOXIDE INSENSITIVE 3
    • Protein OZONE-SENSITIVE 1
    • Protein RADICAL-INDUCED CELL DEATH 3
    • Protein SLOW ANION CHANNEL-ASSOCIATED 1

Gene names

    • Name
      SLAC1
    • Synonyms
      CDI3
      , OZS1
      , RCD3
    • ORF names
      F5O11.23
      , T12C24.3
    • Ordered locus names
      At1g12480

Organism names

  • Taxonomic identifier
  • Strain
    • cv. Columbia
  • Taxonomic lineage
    Eukaryota > Viridiplantae > Streptophyta > Embryophyta > Tracheophyta > Spermatophyta > Magnoliopsida > eudicotyledons > Gunneridae > Pentapetalae > rosids > malvids > Brassicales > Brassicaceae > Camelineae > Arabidopsis

Accessions

  • Primary accession
    Q9LD83

Proteomes

Organism-specific databases

Genome annotation databases

Subcellular Location

Cell membrane
; Multi-pass membrane protein

Features

Showing features for topological domain, transmembrane.

Type
IDPosition(s)Description
Topological domain1-189Cytoplasmic
Transmembrane190-210Helical
Topological domain211-216Extracellular
Transmembrane217-237Helical
Topological domain238-265Cytoplasmic
Transmembrane266-286Helical
Topological domain287-295Extracellular
Transmembrane296-316Helical
Topological domain317-325Cytoplasmic
Transmembrane326-346Helical
Topological domain347-352Extracellular
Transmembrane353-373Helical
Topological domain374-388Cytoplasmic
Transmembrane389-409Helical
Topological domain410-418Extracellular
Transmembrane419-439Helical
Topological domain440Cytoplasmic
Transmembrane441-463Helical
Topological domain464-479Extracellular
Transmembrane480-500Helical
Topological domain501-556Cytoplasmic

Keywords

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.

TypeIDPosition(s)Description
Mutagenesis38In slac1-6; normal ozone-triggered rapid transient decrease (RTD) in stomatal conductance.
Mutagenesis120In slac1-7; impaired ozonetriggered rapid transient decrease (RTD) in stomatal conductance.
Mutagenesis146In slac1-8; impaired ozone-triggered rapid transient decrease (RTD) in stomatal conductance.
Mutagenesis194In 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.
Mutagenesis450Enhanced and constitutive anion transport activity. Impaired anion transport activity; when associated with D-194.
Mutagenesis450Enhanced and constitutive anion transport activity.
Mutagenesis450Impaired anion transport activity.
Mutagenesis456In 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.

Go to variant viewer

PTM/Processing

Features

Showing features for chain, modified residue.

Type
IDPosition(s)Description
ChainPRO_00004042591-556Guard cell S-type anion channel SLAC1
Modified residue59Phosphoserine; by SRK2E
Modified residue86Phosphoserine; by SRK2E
Modified residue113Phosphoserine; by SRK2E
Modified residue120Phosphoserine; by SRK2E
Modified residue146Phosphoserine

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).

Keywords

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).

Binary interactions

TypeEntry 1Entry 2Number of experimentsIntAct
BINARY Q9LD83CPK21 Q9ZSA22EBI-11174918, EBI-8519603
BINARY Q9LD83CPK23 Q9M1014EBI-11174918, EBI-15847592
BINARY Q9LD83SRK2E Q940H68EBI-11174918, EBI-782514

Protein-protein interaction databases

Family & Domains

Features

Showing features for region, coiled coil, compositional bias.

Type
IDPosition(s)Description
Region1-103Disordered
Coiled coil10-36
Compositional bias27-41Polar residues
Compositional bias67-82Basic and acidic residues

Sequence similarities

Belongs to the SLAC1 S-type anion channel family.

Keywords

Phylogenomic databases

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Length
    556
  • Mass (Da)
    63,235
  • Last updated
    2000-10-01 v1
  • Checksum
    E2E310F026EE0C01
MERKQSNAHSTFADINEVEDEAEQELQQQENNNNKRFSGNRGPNRGKQRPFRGFSRQVSLETGFSVLNRESRERDDKKSLPRSGRSFGGFESGGIINGGDGRKTDFSMFRTKSTLSKQKSLLPSIIRERDIENSLRTEDGETKDDSINENVSAGRYFAALRGPELDEVKDNEDILLPKEEQWPFLLRFPIGCFGICLGLSSQAVLWLALAKSPATNFLHITPLINLVVWLFSLVVLVSVSFTYILKCIFYFEAVKREYFHPVRVNFFFAPWVVCMFLAISVPPMFSPNRKYLHPAIWCVFMGPYFFLELKIYGQWLSGGKRRLCKVANPSSHLSVVGNFVGAILASKVGWDEVAKFLWAVGFAHYLVVFVTLYQRLPTSEALPKELHPVYSMFIAAPSAASIAWNTIYGQFDGCSRTCFFIALFLYISLVARINFFTGFKFSVAWWSYTFPMTTASVATIKYAEAVPGYPSRALALTLSFISTAMVCVLFVSTLLHAFVWQTLFPNDLAIAITKRKLTREKKPFKRAYDLKRWTKQALAKKISAEKDFEAEEESHH

Features

Showing features for compositional bias.

TypeIDPosition(s)Description
Compositional bias27-41Polar residues
Compositional bias67-82Basic and acidic residues

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
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

Genome annotation databases

Similar Proteins

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