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Endosperm transfer cell-specific genes and proteins: structure, function and applications in biotechnology.

Lopato S, Borisjuk N, Langridge P, Hrmova M - Front Plant Sci (2014)

Bottom Line: The success of molecular biology-based approaches to manipulating ETC function is dependent on a thorough understanding of the functions of ETC-specific genes and ETC-specific promoters.The aim of this review is to summarize the existing data on structure and function of ETC-specific genes and their products.Potential applications of ETC-specific genes, and in particular their promoters for biotechnology will be discussed.

View Article: PubMed Central - PubMed

Affiliation: Australian Centre for Plant Functional Genomics, University of Adelaide Glen Osmond, SA, Australia.

ABSTRACT
Endosperm transfer cells (ETC) are one of four main types of cells in endosperm. A characteristic feature of ETC is the presence of cell wall in-growths that create an enlarged plasma membrane surface area. This specialized cell structure is important for the specific function of ETC, which is to transfer nutrients from maternal vascular tissue to endosperm. ETC-specific genes are of particular interest to plant biotechnologists, who use genetic engineering to improve grain quality and yield characteristics of important field crops. The success of molecular biology-based approaches to manipulating ETC function is dependent on a thorough understanding of the functions of ETC-specific genes and ETC-specific promoters. The aim of this review is to summarize the existing data on structure and function of ETC-specific genes and their products. Potential applications of ETC-specific genes, and in particular their promoters for biotechnology will be discussed.

No MeSH data available.


Three-dimensional structure of the AHK5RD-AHP1 complex from Arabidopsis thaliana (PDB 4EUK), consisting of the histidine-containing phosphotransfer (AHP1, green) and kinase (AHK5RD, yellow) region, is shown in two orthogonal orientations. The structure of the complex in panel A is rotated by approximately 90 degrees to produce a view shown in panel B. The mechanism of intermolecular phosphotransfer mediated by the Arabidopsis AHK5RD-AHP1 complex. Maize ZmHP2 (PDB 1WN0, smudge green), Medicago truncatula MtHPT1 (PDB 3US6, limon green) and rice OsHPT (PDB 1YVI, forest green) are superposed over the Arabidopsis AHP1. The His in AHP1 and Asp in AHK5RD residues that respectively donate and accept a phosphoryl group are shown in sticks in atomic green and yellow colors, respectively. The octahedral coordination geometry of Mg2+ (green sphere) participating in the phosphotransfer reaction is indicated by black dashes (atomic distances between 1.9 Å and 2.0 Å), where Mg2+ is coordinated by Asp from AHK5RD, three water molecules (red spheres) and two other residues (Asp and Cys) of AHK5RD. The distance of 3.4 Å between His from AHP1 and one of the water molecules is also shown.
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Figure 2: Three-dimensional structure of the AHK5RD-AHP1 complex from Arabidopsis thaliana (PDB 4EUK), consisting of the histidine-containing phosphotransfer (AHP1, green) and kinase (AHK5RD, yellow) region, is shown in two orthogonal orientations. The structure of the complex in panel A is rotated by approximately 90 degrees to produce a view shown in panel B. The mechanism of intermolecular phosphotransfer mediated by the Arabidopsis AHK5RD-AHP1 complex. Maize ZmHP2 (PDB 1WN0, smudge green), Medicago truncatula MtHPT1 (PDB 3US6, limon green) and rice OsHPT (PDB 1YVI, forest green) are superposed over the Arabidopsis AHP1. The His in AHP1 and Asp in AHK5RD residues that respectively donate and accept a phosphoryl group are shown in sticks in atomic green and yellow colors, respectively. The octahedral coordination geometry of Mg2+ (green sphere) participating in the phosphotransfer reaction is indicated by black dashes (atomic distances between 1.9 Å and 2.0 Å), where Mg2+ is coordinated by Asp from AHK5RD, three water molecules (red spheres) and two other residues (Asp and Cys) of AHK5RD. The distance of 3.4 Å between His from AHP1 and one of the water molecules is also shown.

Mentions: Two component signaling (TCS) was initially discovered in 1981 for bacteria (Hall and Silhavy, 1981), and its involvement in nearly all signal transduction events has been demonstrated. Existence of TCS in plants was revealed for the first time in 1996 (Kakimoto, 1996). The first type of TCS components described in plants are membrane-localized receptor histidine kinases (HK), responsible for the perception of signals transferred by ligand molecules, usually hormones. The binding of a ligand molecule leads to auto-phosphorylation of the receptor domain and intra-molecular transfer of the phosphoryl residue to the receiver domain of the HK (Hwang and Sheen, 2001). This is followed by phosphate transfer to a small soluble histidine phospho-transfer protein (HP), which is able to move to the nucleus. The structural characteristics of the AHK5RD-AHP1 complex from Arabidopsis thaliana (Bauer et al., 2013), suggest the process for transfer of the phosphoryl group from AHK5RD to AHP1 (Figure 2). HP proteins from maize (Sugawara et al., 2005), Medicago truncatula (Ruszkowski et al., 2013) and rice (Wesenberg et al., unpublished data, PDB 1YVI) superimposed over the AHP1 protein from Arabidopsis indicate that HP acceptor proteins from diverse plant species fold similarly, and that interfaces between HP and kinases are highly conserved (Figure 2). Further, comparison of the level of conservation of residues at the binding interface region of 22 HP proteins from 16 plant species including those from Arabidopsis, reveals a remarkably high level of preservation of architecture in HP proteins; in particular the spatial positions of a key His residue. It is therefore expected that the mode of action of the AHK5RD-AHP1 complex serves as a paradigm to understand the function of TCS in higher plants at the molecular level (Bauer et al., 2013). Analogous machineries of intermolecular phosphotransfers are likely to operate in both mono- and dicotyledonous plants. In the nucleus, HP activates type-B response regulators (RR), which are a subfamily of MYB transcription factors (TF). Members of this MYB subfamily in turn activate target genes, including genes encoding the type-A RR, which are usually negative regulators of hormone signaling pathways (Hwang and Sheen, 2001).


Endosperm transfer cell-specific genes and proteins: structure, function and applications in biotechnology.

Lopato S, Borisjuk N, Langridge P, Hrmova M - Front Plant Sci (2014)

Three-dimensional structure of the AHK5RD-AHP1 complex from Arabidopsis thaliana (PDB 4EUK), consisting of the histidine-containing phosphotransfer (AHP1, green) and kinase (AHK5RD, yellow) region, is shown in two orthogonal orientations. The structure of the complex in panel A is rotated by approximately 90 degrees to produce a view shown in panel B. The mechanism of intermolecular phosphotransfer mediated by the Arabidopsis AHK5RD-AHP1 complex. Maize ZmHP2 (PDB 1WN0, smudge green), Medicago truncatula MtHPT1 (PDB 3US6, limon green) and rice OsHPT (PDB 1YVI, forest green) are superposed over the Arabidopsis AHP1. The His in AHP1 and Asp in AHK5RD residues that respectively donate and accept a phosphoryl group are shown in sticks in atomic green and yellow colors, respectively. The octahedral coordination geometry of Mg2+ (green sphere) participating in the phosphotransfer reaction is indicated by black dashes (atomic distances between 1.9 Å and 2.0 Å), where Mg2+ is coordinated by Asp from AHK5RD, three water molecules (red spheres) and two other residues (Asp and Cys) of AHK5RD. The distance of 3.4 Å between His from AHP1 and one of the water molecules is also shown.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3936200&req=5

Figure 2: Three-dimensional structure of the AHK5RD-AHP1 complex from Arabidopsis thaliana (PDB 4EUK), consisting of the histidine-containing phosphotransfer (AHP1, green) and kinase (AHK5RD, yellow) region, is shown in two orthogonal orientations. The structure of the complex in panel A is rotated by approximately 90 degrees to produce a view shown in panel B. The mechanism of intermolecular phosphotransfer mediated by the Arabidopsis AHK5RD-AHP1 complex. Maize ZmHP2 (PDB 1WN0, smudge green), Medicago truncatula MtHPT1 (PDB 3US6, limon green) and rice OsHPT (PDB 1YVI, forest green) are superposed over the Arabidopsis AHP1. The His in AHP1 and Asp in AHK5RD residues that respectively donate and accept a phosphoryl group are shown in sticks in atomic green and yellow colors, respectively. The octahedral coordination geometry of Mg2+ (green sphere) participating in the phosphotransfer reaction is indicated by black dashes (atomic distances between 1.9 Å and 2.0 Å), where Mg2+ is coordinated by Asp from AHK5RD, three water molecules (red spheres) and two other residues (Asp and Cys) of AHK5RD. The distance of 3.4 Å between His from AHP1 and one of the water molecules is also shown.
Mentions: Two component signaling (TCS) was initially discovered in 1981 for bacteria (Hall and Silhavy, 1981), and its involvement in nearly all signal transduction events has been demonstrated. Existence of TCS in plants was revealed for the first time in 1996 (Kakimoto, 1996). The first type of TCS components described in plants are membrane-localized receptor histidine kinases (HK), responsible for the perception of signals transferred by ligand molecules, usually hormones. The binding of a ligand molecule leads to auto-phosphorylation of the receptor domain and intra-molecular transfer of the phosphoryl residue to the receiver domain of the HK (Hwang and Sheen, 2001). This is followed by phosphate transfer to a small soluble histidine phospho-transfer protein (HP), which is able to move to the nucleus. The structural characteristics of the AHK5RD-AHP1 complex from Arabidopsis thaliana (Bauer et al., 2013), suggest the process for transfer of the phosphoryl group from AHK5RD to AHP1 (Figure 2). HP proteins from maize (Sugawara et al., 2005), Medicago truncatula (Ruszkowski et al., 2013) and rice (Wesenberg et al., unpublished data, PDB 1YVI) superimposed over the AHP1 protein from Arabidopsis indicate that HP acceptor proteins from diverse plant species fold similarly, and that interfaces between HP and kinases are highly conserved (Figure 2). Further, comparison of the level of conservation of residues at the binding interface region of 22 HP proteins from 16 plant species including those from Arabidopsis, reveals a remarkably high level of preservation of architecture in HP proteins; in particular the spatial positions of a key His residue. It is therefore expected that the mode of action of the AHK5RD-AHP1 complex serves as a paradigm to understand the function of TCS in higher plants at the molecular level (Bauer et al., 2013). Analogous machineries of intermolecular phosphotransfers are likely to operate in both mono- and dicotyledonous plants. In the nucleus, HP activates type-B response regulators (RR), which are a subfamily of MYB transcription factors (TF). Members of this MYB subfamily in turn activate target genes, including genes encoding the type-A RR, which are usually negative regulators of hormone signaling pathways (Hwang and Sheen, 2001).

Bottom Line: The success of molecular biology-based approaches to manipulating ETC function is dependent on a thorough understanding of the functions of ETC-specific genes and ETC-specific promoters.The aim of this review is to summarize the existing data on structure and function of ETC-specific genes and their products.Potential applications of ETC-specific genes, and in particular their promoters for biotechnology will be discussed.

View Article: PubMed Central - PubMed

Affiliation: Australian Centre for Plant Functional Genomics, University of Adelaide Glen Osmond, SA, Australia.

ABSTRACT
Endosperm transfer cells (ETC) are one of four main types of cells in endosperm. A characteristic feature of ETC is the presence of cell wall in-growths that create an enlarged plasma membrane surface area. This specialized cell structure is important for the specific function of ETC, which is to transfer nutrients from maternal vascular tissue to endosperm. ETC-specific genes are of particular interest to plant biotechnologists, who use genetic engineering to improve grain quality and yield characteristics of important field crops. The success of molecular biology-based approaches to manipulating ETC function is dependent on a thorough understanding of the functions of ETC-specific genes and ETC-specific promoters. The aim of this review is to summarize the existing data on structure and function of ETC-specific genes and their products. Potential applications of ETC-specific genes, and in particular their promoters for biotechnology will be discussed.

No MeSH data available.