| Structural highlights
Function
[ALMT1_ARATH] Malate transporter critical for aluminum tolerance. The STOP1 transcription factor is required for ALMT1 expression.[1] [2] [3] [4]
Publication Abstract from PubMed
The plant aluminum (Al)-activated malate transporter ALMT1 mediates the efflux of malate to chelate the Al in acidic soils and underlies the plant Al resistance. Here we present cryo-electron microscopy (cryo-EM) structures of Arabidopsis thaliana ALMT1 (AtALMT1) in the apo, malate-bound, and Al-bound states at neutral and/or acidic pH at up to 3.0 A resolution. The AtALMT1 dimer assembles an anion channel and each subunit contains six transmembrane helices (TMs) and six cytosolic alpha-helices. Two pairs of Arg residues are located in the center of the channel pore and contribute to malate recognition. Al binds at the extracellular side of AtALMT1 and induces conformational changes of the TM1-2 loop and the TM5-6 loop, resulting in the opening of the extracellular gate. These structures, along with electrophysiological measurements, molecular dynamic simulations, and mutagenesis study in Arabidopsis, elucidate the structural basis for Al-activated malate transport by ALMT1.
Structural basis of ALMT1-mediated aluminum resistance in Arabidopsis.,Wang J, Yu X, Ding ZJ, Zhang X, Luo Y, Xu X, Xie Y, Li X, Yuan T, Zheng SJ, Yang W, Guo J Cell Res. 2021 Nov 19. pii: 10.1038/s41422-021-00587-6. doi:, 10.1038/s41422-021-00587-6. PMID:34799726[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Hoekenga OA, Maron LG, Pineros MA, Cancado GM, Shaff J, Kobayashi Y, Ryan PR, Dong B, Delhaize E, Sasaki T, Matsumoto H, Yamamoto Y, Koyama H, Kochian LV. AtALMT1, which encodes a malate transporter, is identified as one of several genes critical for aluminum tolerance in Arabidopsis. Proc Natl Acad Sci U S A. 2006 Jun 20;103(25):9738-43. Epub 2006 Jun 1. PMID:16740662 doi:http://dx.doi.org/0602868103
- ↑ Kobayashi Y, Hoekenga OA, Itoh H, Nakashima M, Saito S, Shaff JE, Maron LG, Pineros MA, Kochian LV, Koyama H. Characterization of AtALMT1 expression in aluminum-inducible malate release and its role for rhizotoxic stress tolerance in Arabidopsis. Plant Physiol. 2007 Nov;145(3):843-52. doi: 10.1104/pp.107.102335. Epub 2007 Sep , 20. PMID:17885092 doi:http://dx.doi.org/10.1104/pp.107.102335
- ↑ Liu J, Magalhaes JV, Shaff J, Kochian LV. Aluminum-activated citrate and malate transporters from the MATE and ALMT families function independently to confer Arabidopsis aluminum tolerance. Plant J. 2009 Feb;57(3):389-99. doi: 10.1111/j.1365-313X.2008.03696.x. Epub 2008 , Oct 30. PMID:18826429 doi:http://dx.doi.org/10.1111/j.1365-313X.2008.03696.x
- ↑ Sawaki Y, Iuchi S, Kobayashi Y, Kobayashi Y, Ikka T, Sakurai N, Fujita M, Shinozaki K, Shibata D, Kobayashi M, Koyama H. STOP1 regulates multiple genes that protect arabidopsis from proton and aluminum toxicities. Plant Physiol. 2009 May;150(1):281-94. doi: 10.1104/pp.108.134700. Epub 2009 Mar , 25. PMID:19321711 doi:http://dx.doi.org/10.1104/pp.108.134700
- ↑ Wang J, Yu X, Ding ZJ, Zhang X, Luo Y, Xu X, Xie Y, Li X, Yuan T, Zheng SJ, Yang W, Guo J. Structural basis of ALMT1-mediated aluminum resistance in Arabidopsis. Cell Res. 2021 Nov 19. pii: 10.1038/s41422-021-00587-6. doi:, 10.1038/s41422-021-00587-6. PMID:34799726 doi:http://dx.doi.org/10.1038/s41422-021-00587-6
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