Dissecting Henipavirus W proteins conformational and fibrillation properties: contribution of their N- and C-terminal constituent domains.

The Nipah and Hendra viruses are severe human pathogens. In addition to the P protein, their P gene also encodes the V and W proteins that share with P their N-terminal intrinsically disordered domain (NTD) and possess distinct C-terminal domains (CTDs). The W protein is a key player in the evasion of the host innate immune response.

Molecular Determinants of Fibrillation in a Viral Amyloidogenic Domain from Combined Biochemical and Biophysical Studies.

The Nipah and Hendra viruses (NiV and HeV) are biosafety level 4 human pathogens classified within the genus of the family. In both NiV and HeV, the gene encoding the Phosphoprotein (P protein), an essential polymerase cofactor, also encodes the V and W proteins. These three proteins, which share an intrinsically disordered N-terminal domain (NTD) and have unique C-terminal domains (CTD), are all known to counteract the host innate immune response, with V and W acting by either counteracting or inhibiting Interferon (IFN) signaling.

Functional benefit of structural disorder for the replication of measles, Nipah and Hendra viruses.

Measles, Nipah and Hendra viruses are severe human pathogens within the Paramyxoviridae family. Their non-segmented, single-stranded, negative-sense RNA genome is encapsidated by the nucleoprotein (N) within a helical nucleocapsid that is the substrate used by the viral RNA-dependent-RNA-polymerase (RpRd) for transcription and replication. The RpRd is a complex made of the large protein (L) and of the phosphoprotein (P), the latter serving as an obligate polymerase cofactor and as a chaperon for N.

Predicting Protein Conformational Disorder and Disordered Binding Sites.

In the last two decades it has become increasingly evident that a large number of proteins adopt either a fully or a partially disordered conformation. Intrinsically disordered proteins are ubiquitous proteins that fulfill essential biological functions while lacking a stable 3D structure. Their conformational heterogeneity is encoded by the amino acid sequence, thereby allowing intrinsically disordered proteins or regions to be recognized based on their sequence properties.

Identification of a Region in the Common Amino-terminal Domain of Hendra Virus P, V, and W Proteins Responsible for Phase Transition and Amyloid Formation.

Henipaviruses are BSL-4 zoonotic pathogens responsible in humans for severe encephalitis. Their V protein is a key player in the evasion of the host innate immune response. We previously showed that the V proteins consist of a long intrinsically disordered N-terminal domain (NTD) and a β-enriched C-terminal domain (CTD).

Extended disorder at the cell surface: The conformational landscape of the ectodomains of syndecans.

Syndecans are membrane proteoglycans regulating extracellular matrix assembly, cell adhesion and signaling. Their ectodomains can be shed from the cell surface, and act as paracrine and autocrine effectors or as competitors of full-length syndecans. We report the first biophysical characterization of the recombinant ectodomains of the four human syndecans using biophysical techniques, and show that they behave like flexible random-coil intrinsically disordered proteins, and adopt several conformation ensembles in solution.

Structures and interactions of syndecans.

The four syndecans identified in mammals are membrane proteoglycans that play major roles in regulating cell behavior, cell signaling, and cell-matrix interactions. The membrane forms of these syndecans function as receptors and co-receptors. Their ectodomains, which are proteolytically released in the extracellular matrix by shedding, also regulate various biological processes.

[Shuttling from the extracellular matrix to the nucleus].

Several enzymes secreted in the extracellular space, such as matrix metalloproteinases and lysyl oxidase, are internalized and translocated to the nucleus, where they may act as proteases and transcription factors to regulate gene expression and enhance apoptosis. Membrane proteoglycan syndecans, glycosaminoglycans and an anti-angiogenic matricryptin of collagen XVIII have also been identified in the nucleus. The nuclear entry of most extracellular proteins is likely mediated by nuclear localizing sequences.