Identification of an Isoflavonoid Transporter Required for the Nodule Establishment of the Rhizobium-Fabaceae Symbiotic Interaction

Nitrogen (N) as well as Phosphorus (P) are key nutrients determining crop productivity. Legumes have developed strategies to overcome nutrient limitation by, for example, forming a symbiotic relationship with N-fixing rhizobia and the release of P-mobilizing exudates and are thus able to grow without supply of N or P fertilizers. The legume-rhizobial symbiosis starts with root release of isoflavonoids that act as signaling molecules perceived by compatible bacteria. Subsequently, bacteria release nod factors, which induce signaling cascades allowing the formation of functional N-fixing nodules. We report here the identification and functional characterization of a plasma membrane-localized MATE-type transporter (LaMATE2) involved in the release of genistein from white lupin roots. The LaMATE2 expression in the root is upregulated under N deficiency as well as low phosphate availability, two nutritional deficiencies that induce the release of this isoflavonoid. LaMATE2 silencing reduced genistein efflux and even more the formation of symbiotic nodules, supporting the crucial role of LaMATE2 in isoflavonoid release and nodulation. Furthermore, silencing of LaMATE2 limited the P-solubilization activity of lupin root exudates. Transport assays in yeast vesicles demonstrated that LaMATE2 acts as a proton-driven isoflavonoid transporter.

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Identification of an isoflavonoid transporter required for the nodule establishment of the Rhizobium-Fabaceae symbiotic interaction

10.1101/2021.07.30.452494 ◽

2021 ◽

Author(s):

Wanda Biala-Leonhard ◽

Laura Zanin ◽

Stefano Gottardi ◽

Rita de Brito Francisco ◽

Silvia Venuti ◽

...

Keyword(s):

Functional Characterization ◽

Crop Productivity ◽

Signaling Cascades ◽

Nutritional Deficiencies ◽

White Lupin ◽

Symbiotic Interaction ◽

Phosphate Availability ◽

Rhizobial Symbiosis

Nitrogen (N) as well as Phosphorus (P) are key nutrients determining crop productivity. Legumes have developed strategies to overcome nutrient limitation by e.g., forming a symbiotic relationship with N-fixing rhizobia and the release of P-mobilizing exudates and are thus able to grow without supply of N or P fertilizers. The legume-rhizobial symbiosis starts with root release of isoflavonoids, that act as signaling molecules perceived by compatible bacteria. Subsequently, bacteria release nod factors, which induce signaling cascades allowing the formation of functional N-fixing nodules. We report here the identification and functional characterization of a plasma membrane-localized MATE-type transporter (LaMATE2) involved in the release of genistein from white lupin roots. The LaMATE2 expression in the root is upregulated under N deficiency as well as low phosphate availability, two nutritional deficiencies that induce the release of this isoflavonoid. LaMATE2 silencing reduced genistein efflux and even more the formation of symbiotic nodules, supporting the crucial role of LaMATE2 in isoflavonoid release and nodulation. Furthermore, silencing of LaMATE2 limited the P-solubilization activity of lupin root exudates. Transport assays in yeast vesicles demonstrated that LaMATE2 acts as a proton-driven isoflavonoid transporter.

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Cloning and functional characterization of the smooth muscle ether-a-go-go-related gene K+ channel. Potential role of a conserved amino acid substitution in the S4 region. Vol. 278 (2003) 2503-2514

Journal of Biological Chemistry ◽

10.1016/s0021-9258(20)67993-5 ◽

2004 ◽

Vol 279 (46) ◽

pp. 48486

Author(s):

Fouzia Shoeb ◽

Anna P. Malykhina ◽

Hamid I. Akbarali

Keyword(s):

Smooth Muscle ◽

Amino Acid ◽

Amino Acid Substitution ◽

Potential Role ◽

Functional Characterization ◽

K Channel ◽

Related Gene ◽

Channel Potential

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Functional characterization of soybean (Glycine max) DIRIGENT genes reveals an important role of GmDIR27 in the regulation of pod dehiscence

Genomics ◽

10.1016/j.ygeno.2020.10.033 ◽

2020 ◽

Author(s):

Xiaofei Ma ◽

Wenying Xu ◽

Tong Liu ◽

Ruying Chen ◽

Hong Zhu ◽

...

Keyword(s):

Glycine Max ◽

Functional Characterization ◽

Pod Dehiscence

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Molecular and Functional Characterization of a ToxR-Regulated Lipoprotein from a Clinical Isolate of Aeromonas hydrophila

Infection and Immunity ◽

10.1128/iai.00402-06 ◽

2006 ◽

Vol 74 (7) ◽

pp. 3742-3755 ◽

Cited By ~ 22

Author(s):

Lakshmi Pillai ◽

Jian Sha ◽

Tatiana E. Erova ◽

Amin A. Fadl ◽

Bijay K. Khajanchi ◽

...

Keyword(s):

Virulence Factor ◽

Aeromonas Hydrophila ◽

Functional Characterization ◽

Affinity Column ◽

Serum Resistance ◽

Classical Pathway ◽

Dependent Manner ◽

T7 Promoter

ABSTRACT Human diseases caused by species of Aeromonas have been classified into two major groups: septicemia and gastroenteritis. In this study, we reported the molecular and functional characterization of a new virulence factor, ToxR-regulated lipoprotein, or TagA, from a diarrheal isolate, SSU, of Aeromonas hydrophila. The tagA gene of A. hydrophila exhibited 60% identity with that of a recently identified stcE gene from Escherichia coli O157:H7, which encoded a protein (StcE) that provided serum resistance to the bacterium and prevented erythrocyte lysis by controlling classical pathway of complement activation by cleaving the complement C1-esterase inhibitor (C1-INH). We purified A. hydrophila TagA as a histidine-tagged fusion protein (rTagA) from E. coli DE3 strain using a T7 promoter-based pET30 expression vector and nickel affinity column chromatography. rTagA cleaved C1-INH in a time-dependent manner. The tagA isogenic mutant of A. hydrophila, unlike its corresponding wild-type (WT) or the complemented strain, was unable to cleave C1-INH, which is required to potentiate the C1-INH-mediated lysis of host and bacterial cells. We indeed demonstrated colocalization of C1-INH and TagA on the bacterial surface by confocal fluorescence microscopy, which ultimately resulted in increased serum resistance of the WT bacterium. Likewise, we delineated the role of TagA in contributing to the enhanced ability of C1-INH to inhibit the classical complement-mediated lysis of erythrocytes. Importantly, we provided evidence that the tagA mutant was significantly less virulent in a mouse model of infection (60%) than the WT bacterium at two 50% lethal doses, which resulted in 100% mortality within 48 h. Taken together, our data provided new information on the role of TagA as a virulence factor in bacterial pathogenesis. This is the first report of TagA characterization from any species of Aeromonas.

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Functional Characterization of Spliceosomal Introns and Identification of U2, U4, and U5 snRNAs in the Deep-Branching Eukaryote Entamoeba histolytica

Eukaryotic Cell ◽

10.1128/ec.00059-07 ◽

2007 ◽

Vol 6 (6) ◽

pp. 940-948 ◽

Cited By ~ 16

Author(s):

Carrie A. Davis ◽

Michael P. S. Brown ◽

Upinder Singh

Keyword(s):

Entamoeba Histolytica ◽

Splice Site ◽

Expressed Sequence Tag ◽

Functional Characterization ◽

Molecular Evidence ◽

Spliceosomal Introns ◽

Accurate Expression ◽

Eukaryotic Organisms

ABSTRACT Pre-mRNA splicing is essential to ensure accurate expression of many genes in eukaryotic organisms. In Entamoeba histolytica, a deep-branching eukaryote, approximately 30% of the annotated genes are predicted to contain introns; however, the accuracy of these predictions has not been tested. In this study, we mined an expressed sequence tag (EST) library representing 7% of amoebic genes and found evidence supporting splicing of 60% of the testable intron predictions, the majority of which contain a GUUUGU 5′ splice site and a UAG 3′ splice site. Additionally, we identified several splice site misannotations, evidence for the existence of 30 novel introns in previously annotated genes, and identified novel genes through uncovering their spliced ESTs. Finally, we provided molecular evidence for the E. histolytica U2, U4, and U5 snRNAs. These data lay the foundation for further dissection of the role of RNA processing in E. histolytica gene expression.

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