Limits...
Modulation of Arabidopsis and monocot root architecture by CLAVATA3/EMBRYO SURROUNDING REGION 26 peptide.

Czyzewicz N, Shi CL, Vu LD, Van De Cotte B, Hodgman C, Butenko MA, Smet ID - J. Exp. Bot. (2015)

Bottom Line: Using chemically synthesized peptide variants, it was found that CLE26 plays an important role in regulating A. thaliana root architecture and interacts with auxin signalling.In addition, through alanine scanning and in silico structural modelling, key residues in the CLE26 peptide sequence that affect its activity are pinpointed.Finally, some interesting similarities and differences regarding the role of CLE26 in regulating monocot root architecture are presented.

View Article: PubMed Central - PubMed

Affiliation: Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Leicestershire LE12 5RD, UK.

No MeSH data available.


Related in: MedlinePlus

Sequence and structure versus activity of CLE26p. (A) Conserved residues between CLE26p and CLV3p are denoted by asterisks. (B) The top-ranked predicted structure with amino acids of the cleaved CLE26 peptide named, the position of a potentially stabilizing salt bridge marked, and the hydroxyl group of Pro-7-Hyp (in the 2S, 4S conformation reported from other studies) depicted in yellow. (C) The solvent-accessible surface (left) and solvent-accessible surface of the opposite face of the peptide in (B) (right) coloured in shades of red or blue to indicate the level of acidity or alkalinity, respectively. (D, E) Quantification of primary root length (D) and emerged lateral root density (E) for CLE26p, CLE27pP7A (~mCLE26p A7), and CLE26p7Hyp-treated wild-type seedlings. The graph indicates the mean ±SE. Statistical significance (Student’s t-test) compared with no peptide treatment is indicated: ***P<0.01.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
getmorefigures.php?uid=PMC4526925&req=5

Figure 5: Sequence and structure versus activity of CLE26p. (A) Conserved residues between CLE26p and CLV3p are denoted by asterisks. (B) The top-ranked predicted structure with amino acids of the cleaved CLE26 peptide named, the position of a potentially stabilizing salt bridge marked, and the hydroxyl group of Pro-7-Hyp (in the 2S, 4S conformation reported from other studies) depicted in yellow. (C) The solvent-accessible surface (left) and solvent-accessible surface of the opposite face of the peptide in (B) (right) coloured in shades of red or blue to indicate the level of acidity or alkalinity, respectively. (D, E) Quantification of primary root length (D) and emerged lateral root density (E) for CLE26p, CLE27pP7A (~mCLE26p A7), and CLE26p7Hyp-treated wild-type seedlings. The graph indicates the mean ±SE. Statistical significance (Student’s t-test) compared with no peptide treatment is indicated: ***P<0.01.

Mentions: CLE26 has similar residues at the N- and C-termini as CLV3 that are critical for correct function in A. thaliana, and mutation of more central amino acids causes a similar reduction in bioactivity to that reported for CLV3 (Kondo et al., 2008) (Fig. 5A). That these amino acids are critical for function indicates that they contribute to the correct conformation for ligand−receptor interaction. Structural analysis of CLE26 indicates that Gly6 and Pro7 form the sharp bend of a hairpin, potentially putting the proteolytic cleavage sites close together. This resembles earlier CLE structure predictions (Meng and Feldman, 2010). Rotamer analysis also showed that this conformation brings Arg5 and Asp8 into close proximity to form a salt bridge, potentially increasing the stability of the mature peptide (Fig. 5B). Surface hydrophobicity analysis suggested that one surface of this structure bulges and is predominantly basic, owing to Arg5, while the opposite surface is uncharged and has a cavity (Fig. 5C). These two surfaces could be involved in binding to receptors. The flanking precursor sequences are predicted to be α-helices, which may interact prior to mature peptide cleavage, facilitating the formation of a hairpin, and one of these could be membrane associated (Supplementary Fig. S7 at JXB online). It has been shown that CLV3p is hydroxylated on each of its proline residues and that the proline at position 7 in the CLV3 peptide is also arabinosylated, enhancing binding to CLV1 and CLV2 (Kondo et al., 2006; Ohyama et al., 2009; Shinohara and Matsubayashi, 2013). CLE26p also contains a proline residue at position 7, and it is worth noting that hydroxyl and arabinose side chains would point towards the arginine–aspartate surface noted above, perturbing their positions slightly (Fig. 5B). Similar modifications in CLE26p might be mimicked by mCLE26pP7A, potentially increasing binding affinity for its orphan receptor and explaining the enhanced biological activity. Indeed, the mCLE26pP7A effect could be mimicked by using a CLE26p variant that is hydroxylated at position 7 (CLE26pP7Hyp) (Fig. 5D,E). The alanine at position 7 allows more flexibility in the arms of the hairpin, potentially enabling the arginine–aspartate surface to adopt a more favourable conformation for binding. Molecular dynamics studies of β-1,2-linked tri-arabinosylated CLV3pP7 suggest that the effect of the trisaccharide is to bring the N- and C-terminal ends of the peptide closer together (Shinohara and Matsubayashi, 2013), making it more like the hairpin model of CLE26.


Modulation of Arabidopsis and monocot root architecture by CLAVATA3/EMBRYO SURROUNDING REGION 26 peptide.

Czyzewicz N, Shi CL, Vu LD, Van De Cotte B, Hodgman C, Butenko MA, Smet ID - J. Exp. Bot. (2015)

Sequence and structure versus activity of CLE26p. (A) Conserved residues between CLE26p and CLV3p are denoted by asterisks. (B) The top-ranked predicted structure with amino acids of the cleaved CLE26 peptide named, the position of a potentially stabilizing salt bridge marked, and the hydroxyl group of Pro-7-Hyp (in the 2S, 4S conformation reported from other studies) depicted in yellow. (C) The solvent-accessible surface (left) and solvent-accessible surface of the opposite face of the peptide in (B) (right) coloured in shades of red or blue to indicate the level of acidity or alkalinity, respectively. (D, E) Quantification of primary root length (D) and emerged lateral root density (E) for CLE26p, CLE27pP7A (~mCLE26p A7), and CLE26p7Hyp-treated wild-type seedlings. The graph indicates the mean ±SE. Statistical significance (Student’s t-test) compared with no peptide treatment is indicated: ***P<0.01.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4526925&req=5

Figure 5: Sequence and structure versus activity of CLE26p. (A) Conserved residues between CLE26p and CLV3p are denoted by asterisks. (B) The top-ranked predicted structure with amino acids of the cleaved CLE26 peptide named, the position of a potentially stabilizing salt bridge marked, and the hydroxyl group of Pro-7-Hyp (in the 2S, 4S conformation reported from other studies) depicted in yellow. (C) The solvent-accessible surface (left) and solvent-accessible surface of the opposite face of the peptide in (B) (right) coloured in shades of red or blue to indicate the level of acidity or alkalinity, respectively. (D, E) Quantification of primary root length (D) and emerged lateral root density (E) for CLE26p, CLE27pP7A (~mCLE26p A7), and CLE26p7Hyp-treated wild-type seedlings. The graph indicates the mean ±SE. Statistical significance (Student’s t-test) compared with no peptide treatment is indicated: ***P<0.01.
Mentions: CLE26 has similar residues at the N- and C-termini as CLV3 that are critical for correct function in A. thaliana, and mutation of more central amino acids causes a similar reduction in bioactivity to that reported for CLV3 (Kondo et al., 2008) (Fig. 5A). That these amino acids are critical for function indicates that they contribute to the correct conformation for ligand−receptor interaction. Structural analysis of CLE26 indicates that Gly6 and Pro7 form the sharp bend of a hairpin, potentially putting the proteolytic cleavage sites close together. This resembles earlier CLE structure predictions (Meng and Feldman, 2010). Rotamer analysis also showed that this conformation brings Arg5 and Asp8 into close proximity to form a salt bridge, potentially increasing the stability of the mature peptide (Fig. 5B). Surface hydrophobicity analysis suggested that one surface of this structure bulges and is predominantly basic, owing to Arg5, while the opposite surface is uncharged and has a cavity (Fig. 5C). These two surfaces could be involved in binding to receptors. The flanking precursor sequences are predicted to be α-helices, which may interact prior to mature peptide cleavage, facilitating the formation of a hairpin, and one of these could be membrane associated (Supplementary Fig. S7 at JXB online). It has been shown that CLV3p is hydroxylated on each of its proline residues and that the proline at position 7 in the CLV3 peptide is also arabinosylated, enhancing binding to CLV1 and CLV2 (Kondo et al., 2006; Ohyama et al., 2009; Shinohara and Matsubayashi, 2013). CLE26p also contains a proline residue at position 7, and it is worth noting that hydroxyl and arabinose side chains would point towards the arginine–aspartate surface noted above, perturbing their positions slightly (Fig. 5B). Similar modifications in CLE26p might be mimicked by mCLE26pP7A, potentially increasing binding affinity for its orphan receptor and explaining the enhanced biological activity. Indeed, the mCLE26pP7A effect could be mimicked by using a CLE26p variant that is hydroxylated at position 7 (CLE26pP7Hyp) (Fig. 5D,E). The alanine at position 7 allows more flexibility in the arms of the hairpin, potentially enabling the arginine–aspartate surface to adopt a more favourable conformation for binding. Molecular dynamics studies of β-1,2-linked tri-arabinosylated CLV3pP7 suggest that the effect of the trisaccharide is to bring the N- and C-terminal ends of the peptide closer together (Shinohara and Matsubayashi, 2013), making it more like the hairpin model of CLE26.

Bottom Line: Using chemically synthesized peptide variants, it was found that CLE26 plays an important role in regulating A. thaliana root architecture and interacts with auxin signalling.In addition, through alanine scanning and in silico structural modelling, key residues in the CLE26 peptide sequence that affect its activity are pinpointed.Finally, some interesting similarities and differences regarding the role of CLE26 in regulating monocot root architecture are presented.

View Article: PubMed Central - PubMed

Affiliation: Division of Plant and Crop Sciences, School of Biosciences, University of Nottingham, Leicestershire LE12 5RD, UK.

No MeSH data available.


Related in: MedlinePlus