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The role of chordin fragments generated by partial tolloid cleavage in regulating BMP activity.

Troilo H, Barrett AL, Wohl AP, Jowitt TA, Collins RF, Bayley CP, Zuk AV, Sengle G, Baldock C - Biochem. Soc. Trans. (2015)

Bottom Line: As Tsg enhances this cleavage process, it serves a dual role as both promoter and inhibitor of BMP signalling.Recent developments in chordin research suggest that rather than simply being by-products, the cleavage fragments of chordin continue to play a role in BMP regulation.In particular, chordin cleavage at the C-terminus potentiates its anti-BMP activity in a type-specific manner.

View Article: PubMed Central - PubMed

Affiliation: Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, U.K.

No MeSH data available.


Related in: MedlinePlus

Structure of the C-terminally Cleaved Chordin Fragment Generated by Tolloid(A) MALS trace showing that following C-terminal cleavage the chordin fragment ∆C remains predominantly monomeric at 0.5 mg ml−1. Mr=102.3 kDa ± 0.038%. (B) Selected class averages (top) and re-projections of the 3D reconstruction (bottom) showing different views of chordin ∆C. (C) 3D TEM model of chordin ∆C generated from ∼10000 negatively stained particles from 20 micrographs using angular reconstruction with EMAN2, shown in three orthogonal orientations. Data collected on a Tecnai G2 Polara electron microscope at 300 kV and 5 Å (1 Å=0.1 nm) pixel. Resolution by Fourier shell correlation=24 Å. All data collected according to the methods described in Troilo et al. [10].
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Figure 2: Structure of the C-terminally Cleaved Chordin Fragment Generated by Tolloid(A) MALS trace showing that following C-terminal cleavage the chordin fragment ∆C remains predominantly monomeric at 0.5 mg ml−1. Mr=102.3 kDa ± 0.038%. (B) Selected class averages (top) and re-projections of the 3D reconstruction (bottom) showing different views of chordin ∆C. (C) 3D TEM model of chordin ∆C generated from ∼10000 negatively stained particles from 20 micrographs using angular reconstruction with EMAN2, shown in three orthogonal orientations. Data collected on a Tecnai G2 Polara electron microscope at 300 kV and 5 Å (1 Å=0.1 nm) pixel. Resolution by Fourier shell correlation=24 Å. All data collected according to the methods described in Troilo et al. [10].

Mentions: A subsequent study in zebrafish observed the effects of mutating the N-terminal, C-terminal or both cleavage sites of chordin to make them resistant to tolloids. N-terminally truncated chordin was a slightly less efficient BMP inhibitor [20]. However C-terminally truncated chordin was a more efficient in vivo BMP-inhibitor in vertebrates, similar to Supersog. It was also found to be present at steady-state levels in the developing embryo at comparable levels to full-length chordin, therefore likely to make a significant physiological contribution to BMP-inhibition. Tolloids are ubiquitous enzymes required for the processing of many essential matrix substrates including collagens. By utilizing either the N- or C-terminal chordin cleavage site tolloids may operate an intrinsic structural fine tune mechanism to yield either BMP-4 or -7 signalling. For instance, cleaving off the N-terminal vWC1 reduces BMP-7 but not BMP-4 inhibition, whereas C-terminal cleavage of vWC4 leads to stronger inhibition of BMP-4 while BMP-7 activity remains unaffected [10]. Our interaction studies with BMP growth factors and chordin cleavage variants combined with bioactivity assays employing human cell lines confirmed the reported in vivo property of chordin ∆C [10]. However, structurally there is little change following cleavage by tolloids either in chordin ∆N [10] or in chordin ∆C as shown in Figure 2. Multi angle light scattering (MALS) shows that, like full-length chordin, the protein is monomeric at 0.5 mg ml−1 (Figure 2A). Negative stain EM single particle analysis, shown in Figures 2(B) and 2(C), reveals a horseshoe-shaped nanoscale conformation similar to that previously described for full-length chordin.


The role of chordin fragments generated by partial tolloid cleavage in regulating BMP activity.

Troilo H, Barrett AL, Wohl AP, Jowitt TA, Collins RF, Bayley CP, Zuk AV, Sengle G, Baldock C - Biochem. Soc. Trans. (2015)

Structure of the C-terminally Cleaved Chordin Fragment Generated by Tolloid(A) MALS trace showing that following C-terminal cleavage the chordin fragment ∆C remains predominantly monomeric at 0.5 mg ml−1. Mr=102.3 kDa ± 0.038%. (B) Selected class averages (top) and re-projections of the 3D reconstruction (bottom) showing different views of chordin ∆C. (C) 3D TEM model of chordin ∆C generated from ∼10000 negatively stained particles from 20 micrographs using angular reconstruction with EMAN2, shown in three orthogonal orientations. Data collected on a Tecnai G2 Polara electron microscope at 300 kV and 5 Å (1 Å=0.1 nm) pixel. Resolution by Fourier shell correlation=24 Å. All data collected according to the methods described in Troilo et al. [10].
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Related In: Results  -  Collection

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Figure 2: Structure of the C-terminally Cleaved Chordin Fragment Generated by Tolloid(A) MALS trace showing that following C-terminal cleavage the chordin fragment ∆C remains predominantly monomeric at 0.5 mg ml−1. Mr=102.3 kDa ± 0.038%. (B) Selected class averages (top) and re-projections of the 3D reconstruction (bottom) showing different views of chordin ∆C. (C) 3D TEM model of chordin ∆C generated from ∼10000 negatively stained particles from 20 micrographs using angular reconstruction with EMAN2, shown in three orthogonal orientations. Data collected on a Tecnai G2 Polara electron microscope at 300 kV and 5 Å (1 Å=0.1 nm) pixel. Resolution by Fourier shell correlation=24 Å. All data collected according to the methods described in Troilo et al. [10].
Mentions: A subsequent study in zebrafish observed the effects of mutating the N-terminal, C-terminal or both cleavage sites of chordin to make them resistant to tolloids. N-terminally truncated chordin was a slightly less efficient BMP inhibitor [20]. However C-terminally truncated chordin was a more efficient in vivo BMP-inhibitor in vertebrates, similar to Supersog. It was also found to be present at steady-state levels in the developing embryo at comparable levels to full-length chordin, therefore likely to make a significant physiological contribution to BMP-inhibition. Tolloids are ubiquitous enzymes required for the processing of many essential matrix substrates including collagens. By utilizing either the N- or C-terminal chordin cleavage site tolloids may operate an intrinsic structural fine tune mechanism to yield either BMP-4 or -7 signalling. For instance, cleaving off the N-terminal vWC1 reduces BMP-7 but not BMP-4 inhibition, whereas C-terminal cleavage of vWC4 leads to stronger inhibition of BMP-4 while BMP-7 activity remains unaffected [10]. Our interaction studies with BMP growth factors and chordin cleavage variants combined with bioactivity assays employing human cell lines confirmed the reported in vivo property of chordin ∆C [10]. However, structurally there is little change following cleavage by tolloids either in chordin ∆N [10] or in chordin ∆C as shown in Figure 2. Multi angle light scattering (MALS) shows that, like full-length chordin, the protein is monomeric at 0.5 mg ml−1 (Figure 2A). Negative stain EM single particle analysis, shown in Figures 2(B) and 2(C), reveals a horseshoe-shaped nanoscale conformation similar to that previously described for full-length chordin.

Bottom Line: As Tsg enhances this cleavage process, it serves a dual role as both promoter and inhibitor of BMP signalling.Recent developments in chordin research suggest that rather than simply being by-products, the cleavage fragments of chordin continue to play a role in BMP regulation.In particular, chordin cleavage at the C-terminus potentiates its anti-BMP activity in a type-specific manner.

View Article: PubMed Central - PubMed

Affiliation: Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, U.K.

No MeSH data available.


Related in: MedlinePlus