TY - JOUR
T1 - Unveiling the Metal-Dependent Aggregation Properties of the C-terminal Region of Amyloidogenic Intrinsically Disordered Protein Isoforms DPF3b and DPF3a
AU - Leyder, Tanguy
AU - Mignon, Julien
AU - Mottet, Denis
AU - Michaux, Catherine
N1 - Funding Information:
J.M., D.M. and C.M. are supported by the Belgian Fund for Scientific Research (F.R.S.-FNRS). J.M. benefits from a Research Fellow FNRS grant.
Publisher Copyright:
© 2022 by the authors.
PY - 2022/12/4
Y1 - 2022/12/4
N2 - Double-PHD fingers 3 (DPF3) is a BAF-associated human epigenetic regulator, which is increasingly recognised as a major contributor to various pathological contexts, such as cardiac defects, cancer, and neurodegenerative diseases. Recently, we unveiled that its two isoforms (DPF3b and DPF3a) are amyloidogenic intrinsically disordered proteins. DPF3 isoforms differ from their C-terminal region (C-TERb and C-TERa), containing zinc fingers and disordered domains. Herein, we investigated the disorder aggregation properties of C-TER isoforms. In agreement with the predictions, spectroscopy highlighted a lack of a highly ordered structure, especially for C-TERa. Over a few days, both C-TERs were shown to spontaneously assemble into similar antiparallel and parallel β-sheet-rich fibrils. Altered metal homeostasis being a neurodegeneration hallmark, we also assessed the influence of divalent metal cations, namely Cu
2+, Mg
2+, Ni
2+, and Zn
2+, on the C-TER aggregation pathway. Circular dichroism revealed that metal binding does not impair the formation of β-sheets, though metal-specific tertiary structure modifications were observed. Through intrinsic and extrinsic fluorescence, we found that metal cations differently affect C-TERb and C-TERa. Cu
2+ and Ni
2+ have a strong inhibitory effect on the aggregation of both isoforms, whereas Mg
2+ impedes C-TERb fibrillation and, on the contrary, enhances that of C-TERa. Upon Zn
2+ binding, C-TERb aggregation is also hindered, and the amyloid autofluorescence of C-TERa is remarkably red-shifted. Using electron microscopy, we confirmed that the metal-induced spectral changes are related to the morphological diversity of the aggregates. While metal-treated C-TERb formed breakable and fragmented filaments, C-TERa fibrils retained their flexibility and packing properties in the presence of Mg
2+ and Zn
2+ cations.
AB - Double-PHD fingers 3 (DPF3) is a BAF-associated human epigenetic regulator, which is increasingly recognised as a major contributor to various pathological contexts, such as cardiac defects, cancer, and neurodegenerative diseases. Recently, we unveiled that its two isoforms (DPF3b and DPF3a) are amyloidogenic intrinsically disordered proteins. DPF3 isoforms differ from their C-terminal region (C-TERb and C-TERa), containing zinc fingers and disordered domains. Herein, we investigated the disorder aggregation properties of C-TER isoforms. In agreement with the predictions, spectroscopy highlighted a lack of a highly ordered structure, especially for C-TERa. Over a few days, both C-TERs were shown to spontaneously assemble into similar antiparallel and parallel β-sheet-rich fibrils. Altered metal homeostasis being a neurodegeneration hallmark, we also assessed the influence of divalent metal cations, namely Cu
2+, Mg
2+, Ni
2+, and Zn
2+, on the C-TER aggregation pathway. Circular dichroism revealed that metal binding does not impair the formation of β-sheets, though metal-specific tertiary structure modifications were observed. Through intrinsic and extrinsic fluorescence, we found that metal cations differently affect C-TERb and C-TERa. Cu
2+ and Ni
2+ have a strong inhibitory effect on the aggregation of both isoforms, whereas Mg
2+ impedes C-TERb fibrillation and, on the contrary, enhances that of C-TERa. Upon Zn
2+ binding, C-TERb aggregation is also hindered, and the amyloid autofluorescence of C-TERa is remarkably red-shifted. Using electron microscopy, we confirmed that the metal-induced spectral changes are related to the morphological diversity of the aggregates. While metal-treated C-TERb formed breakable and fragmented filaments, C-TERa fibrils retained their flexibility and packing properties in the presence of Mg
2+ and Zn
2+ cations.
KW - Double doigt PHD 3 (DPF3)
KW - Protéine intrinsèquement désordonnée
KW - Maladies neurodégénératives
KW - Agrégation
KW - Fibrillation amyloïde
KW - Cations métalliques
KW - Spectroscopie
KW - Autofluorescence du bleu profond
KW - Microscopie électronique
KW - Double-PHD fingers 3 (DPF3)
KW - Intrinsically disordered protein
KW - Neurodegenerative disease
KW - Aggregation
KW - Amyloid fibrillation
KW - Metal cations
KW - Spectroscopy
KW - Deep-blue autofluorescence
KW - Electron microscopy
KW - intrinsically disordered protein
KW - amyloid fibrillation
KW - aggregation
KW - neurodegenerative diseases
KW - metal cations
KW - spectroscopy
KW - electron microscopy
KW - double-PHD fingers 3 (DPF3)
KW - deep-blue autofluorescence
UR - http://www.scopus.com/inward/record.url?scp=85143649839&partnerID=8YFLogxK
U2 - 10.3390/ijms232315291
DO - 10.3390/ijms232315291
M3 - Article
SN - 1661-6596
VL - 23
JO - International Journal of Molecular Sciences
JF - International Journal of Molecular Sciences
IS - 23
M1 - 15291
ER -