Homologue structure of the SLAC1 anion channel for closing stomata in leaves

Chen, Yu Hang; Hu, Lei; Punta, Marco; Bruni, Renato; Hillerich, B.; Kloss, Brian; Rost, Burkhard; Love, J.; Siegelbaum, Steven A.; Hendrickson, Wayne A.

doi:10.1038/nature09487

Cited by 125 publications

(177 citation statements)

References 57 publications

Supporting

Mentioning

168

Contrasting

Order By: Relevance

“…The crystal structure of Hi-TehA, a bacterial homolog of SLAC1, suggests that an inner five-helix transmembrane ring forms the pore with a central phenylalanine residue, which is invariant in this superfamily and seemingly blocks the pore (Chen et al, 2010;Dreyer et al, 2012). Whereas wild-type Hi-TehA showed no ion transport when expressed in oocytes, mutation of the blocking phenylalanine residue (Phe-262) to alanine rendered this channel constitutively active (Chen et al, 2010).…”

Section: Homology Modeling Of Slac1 and Slah2 To Reveal Potential Sitmentioning

confidence: 99%

“…Whereas wild-type Hi-TehA showed no ion transport when expressed in oocytes, mutation of the blocking phenylalanine residue (Phe-262) to alanine rendered this channel constitutively active (Chen et al, 2010). Similarly, replacement of the pore phenylalanine (SLAC1 F450A) also gated SLAC1 (constitutively) open even in the absence of an activating kinase (Chen et al, 2010).…”

Section: Homology Modeling Of Slac1 and Slah2 To Reveal Potential Sitmentioning

confidence: 99%

“…Both the SLAC1 and SLAH3 channels interact with distinct kinasephosphatase pairs shown to be associated with water stress signaling (Geiger et al, 2009b(Geiger et al, , 2010(Geiger et al, , 2011Brandt et al, 2012;Scherzer et al, 2012). Although anion channels of the SLAC/SLAH family show homology to tellurite resistance/C(4)-dicarboxylate transporters expressed in bacteria, archaea, and fungi, SLAC1 and SLAH3 exhibit a preference for nitrate and chloride but not for malate (Schmidt and Schroeder, 1994;Geiger et al, 2009b;Chen et al, 2010). These channels are further characterized by a NO 3 2 /Cl 2 permeability ratio of ;10, in the case of SLAC1, and of 20 for SLAH3 (Geiger et al, 2009b(Geiger et al, , 2011.…”

Section: Introductionmentioning

confidence: 99%

“…While these early studies did not elucidate the function of the bacterial SLAC1 homolog, recently, Chen et al (2010) determined the crystal structure of TehA from the bacteria Haemophilus influenzae (Hi-TehA). The structure of Hi-TehA (and the SLAC1 model derived from it) shows a trimeric assembly composed of quasisymmetrical subunits.…”

Section: Introductionmentioning

confidence: 99%

“…The inner five-helix transmembrane ring contains a pore with a central, highly conserved, phenylalanine residue (in Arabidopsis SLAC1, F450) potentially representing the anion gate. Mutation of this pore phenylalanine turned HiTehA and its plant homolog, At-SLAC1, into an open anion channel (Chen et al, 2010). However, the molecular determinants of anion selectivity remain unclear.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

A Single-Pore Residue Renders the Arabidopsis Root Anion Channel SLAH2 Highly Nitrate Selective

et al. 2014

View full text Add to dashboard Cite

In contrast to animal cells, plants use nitrate as a major source of nitrogen. Following the uptake of nitrate, this major macronutrient is fed into the vasculature for long-distance transport. The Arabidopsis thaliana shoot expresses the anion channel SLOW ANION CHANNEL1 (SLAC1) and its homolog SLAC1 HOMOLOGOUS3 (SLAH3), which prefer nitrate as substrate but cannot exclude chloride ions. By contrast, we identified SLAH2 as a nitrate-specific channel that is impermeable for chloride. To understand the molecular basis for nitrate selection in the SLAH2 channel, SLAC1 and SLAH2 were modeled to the structure of HiTehA, a distantly related bacterial member. Structure-guided site-directed mutations converted SLAC1 into a SLAH2-like nitrate-specific anion channel and vice versa. Our findings indicate that two pore-occluding phenylalanines constrict the pore. The selectivity filter of SLAC/SLAH anion channels is determined by the polarity of pore-lining residues located on alpha helix 3. Changing the polar character of a single amino acid side chain (Ser-228) to a nonpolar residue turned the nitrate-selective SLAH2 into a chloride/nitrate-permeable anion channel. Thus, the molecular basis of the anion specificity of SLAC/SLAH anion channels seems to be determined by the presence and constellation of polar side chains that act in concert with the two pore-occluding phenylalanines.

show abstract

Section: Homology Modeling Of Slac1 and Slah2 To Reveal Potential Sitmentioning

confidence: 99%

Section: Homology Modeling Of Slac1 and Slah2 To Reveal Potential Sitmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

A Single-Pore Residue Renders the Arabidopsis Root Anion Channel SLAH2 Highly Nitrate Selective

et al. 2014

View full text Add to dashboard Cite

show abstract

High‐Throughput Cloning and Expression of Integral Membrane Proteins in Escherichia coli

Bruni

Kloss

2013

CP Protein Science

Self Cite

View full text Add to dashboard Cite

Recently, several structural genomics centers have been established and a remarkable number of three-dimensional structures of soluble proteins have been solved. For membrane proteins, the number of structures solved has been significantly trailing those for their soluble counterparts, not least because over-expression and purification of membrane proteins is a much more arduous process. By using high throughput technologies, a large number of membrane protein targets can be screened simultaneously and a greater number of expression and purification conditions can be employed, leading to a higher probability of successfully determining the structure of membrane proteins. This unit describes the cloning, expression and screening of membrane proteins using high throughput methodologies developed in our laboratory. Basic Protocol 1 deals with the cloning of inserts into expression vectors by ligation-independent cloning. Basic Protocol 2 describes the expression and purification of the target proteins on a miniscale. Lastly, for the targets that express at the miniscale, basic protocols 3 and 4 outline the methods employed for the expression and purification of targets at the midi-scale, as well as a procedure for detergent screening and identification of detergent(s) in which the target protein is stable.

show abstract

TheSLAC1Anion Channel

Hõrak¹

2020

Encyclopedia of Life Sciences

View full text Add to dashboard Cite

The balance between CO 2 uptake for photosynthesis and water loss through transpiration determines plant growth and productivity. Guard cells form stomatal pores in plant epidermis that adjust this balance via volume changes that control stomatal aperture. Guard cell volume is regulated by fluxes of ions and water across the membrane via various ion channels. The slow anion channel 1 (SLAC1) is essential for efficient stomatal regulation, as it is the major mediator of the efflux of anions from guard cells during stomatal closure. The activation of SLAC1 requires phosphorylation and is the end point of signalling pathways initiated by abiotic and biotic triggers that cause stomata to close, such as the phytohormone abscisic acid, elevated CO 2 levels, darkness, low air humidity, ozone; and pathogen and damage‐associated molecular patterns and hormones. SLAC1 is conserved in evolution, but SLACs in different plant groups have different mechanisms of regulation. Key Concepts SLAC1 is the major guard cell slow‐type anion channel that needs to be activated by phosphorylation in the N ‐ and C ‐terminal regions for stomatal closure in response to endogenous and environmental stimuli. The plant hormone abscisic acid (ABA) triggers SLAC1 activation through a signalling pathway that involves ABA receptors and PP2C phosphatases, which regulate the Ca 2+ ‐independent kinase OST1 and several Ca 2+ ‐dependent protein kinases that phosphorylate SLAC1. The same pathway is involved in SLAC1 activation in response to darkness, CO 2 , ozone and low air humidity. Elevated CO 2 activates SLAC1 via bicarbonate, which directly enhances ion channel activity. The Raf‐type kinase HT1 and mitogen‐activated protein kinases MPK12 and MPK4 regulate SLAC1 activation in response to CO 2 , but not ABA, contributing to a CO 2 ‐specific branch of SLAC1 activation. Pathogen‐associated molecules trigger the activation of SLAC1 and its homologue SLAH3 that contributes to guard cell anion currents. SLAH3 is the key anion channel in stomatal response to fungal chitin, whereas SLAC1, SLAH3 and OST1 contribute to bacterial flagellin‐induced stomatal closure. SLAC1 and OST1 are conserved in early land plants, such as mosses, lycophytes and ferns, but their role in these plants needs further study. The regulation of SLAC1 anion channel differs among plant groups – for example, the monocot SLACs, unlike Arabidopsis SLAC1, require external nitrate for activation.

show abstract

Homologue structure of the SLAC1 anion channel for closing stomata in leaves

Cited by 125 publications

References 57 publications

A Single-Pore Residue Renders the Arabidopsis Root Anion Channel SLAH2 Highly Nitrate Selective

A Single-Pore Residue Renders the Arabidopsis Root Anion Channel SLAH2 Highly Nitrate Selective

High‐Throughput Cloning and Expression of Integral Membrane Proteins in Escherichia coli

TheSLAC1Anion Channel

Contact Info

Product

Resources

About