Regeneration of actin filament branches from the same Arp2/3 complex.

Branched actin filaments are found in many key cellular structures. Branches are nucleated by the Arp2/3 complex activated by nucleation-promoting factor (NPF) proteins and bound to the side of preexisting "mother" filaments. Over time, branches dissociate from their mother filament, leading to network reorganization and turnover, but this mechanism is less understood.

Direct observation of the conformational states of formin mDia1 at actin filament barbed ends and along the filament.

The fine regulation of actin polymerization is essential to control cell motility and architecture and to perform essential cellular functions. Formins are key regulators of actin filament assembly, known to processively elongate filament barbed ends and increase their polymerization rate. Different models have been extrapolated to describe the molecular mechanism governing the processive motion of formin FH2 domains at polymerizing barbed ends.

Synthesis, phloem mobility and induced plant resistance of synthetic salicylic acid amino acid or glucose conjugates.

Background: The growing demand for food, combined with a strong social expectation for a diet produced with fewer conventional agrochemical inputs, has led to the development of new alternatives in plant protection worldwide. Among different possibilities, the stimulation of the plant innate immune system by chemicals represents a novel and promising way. The vectorization strategy of an active ingredient that we previously developed with fungicides can potentially extend to salicylic acid (SA) or its halogenated analogues.

Actin filament oxidation by MICAL1 suppresses protections from cofilin-induced disassembly.

Proteins of the ADF/cofilin family play a central role in the disassembly of actin filaments, and their activity must be tightly regulated in cells. Recently, the oxidation of actin filaments by the enzyme MICAL1 was found to amplify the severing action of cofilin through unclear mechanisms. Using single filament experiments in vitro, we found that actin filament oxidation by MICAL1 increases, by several orders of magnitude, both cofilin binding and severing rates, explaining the dramatic synergy between oxidation and cofilin for filament disassembly.

Geometrical Constraints Greatly Hinder Formin mDia1 Activity.

Formins are one of the central players in the assembly of most actin networks in cells. The sensitivity of these processive molecular machines to mechanical tension is now well established. However, how the activity of formins is affected by geometrical constraints related to network architecture, such as filament cross-linking and formin spatial confinement, remains largely unknown.

Design on a Rational Basis of High-Affinity Peptides Inhibiting the Histone Chaperone ASF1.

Anti-silencing function 1 (ASF1) is a conserved H3-H4 histone chaperone involved in histone dynamics during replication, transcription, and DNA repair. Overexpressed in proliferating tissues including many tumors, ASF1 has emerged as a promising therapeutic target. Here, we combine structural, computational, and biochemical approaches to design peptides that inhibit the ASF1-histone interaction.

Surgical treatment of orbital hypertelorism: Historical evolution and development prospects.

Orbital hypertelorism (OR.H) is defined as an abnormal increase in the distance between the two orbits secondary to a skeletal anomaly, and it occurs in association with numerous congenital craniofacial malformations. Since its description by Greig in 1924, OR.

Management of non-syndromic craniosynostoses in France in 2015: A national survey.

Purpose: Craniosynostoses are managed by surgical and anaesthetic teams in specialist centres. Despite the availability of international guidelines, the perioperative management of craniosynostoses remains highly variable between centres. The aim of our study was to describe the different protocols for the management of non-syndromic craniosynostoses in France in 2015.

Using Microfluidics Single Filament Assay to Study Formin Control of Actin Assembly.

Formin is a highly processive motor that offers very unique features to control the elongation of actin filaments. When bound to the filament barbed-end, it enhances the addition of profilin-actin from solution to dramatically accelerate actin assembly. The different aspects of formin activity can be explored using single actin filament assays based on the combination of microfluidics with fluorescence microscopy.

IL11RA-related Crouzon-like autosomal recessive craniosynostosis in 10 new patients: Resemblances and differences.

By describing 10 new patients recruited in centres for Human Genetics, we further delineate the clinical spectrum of a Crouzon-like craniosynostosis disorder, officially termed craniosynostosis and dental anomalies (MIM614188). Singularly, it is inherited according to an autosomal recessive mode of inheritance. We identified six missense mutations in IL11RA, a gene encoding the alpha subunit of interleukin 11 receptor, 4 of them being novel, including 2 in the Ig-like C2-type domain.

Modulation of formin processivity by profilin and mechanical tension.

Formins are major regulators of actin networks. They enhance actin filament dynamics by remaining processively bound to filament barbed ends. How biochemical and mechanical factors affect formin processivity are open questions.

Descriptions of Mikrocytos veneroïdes n. sp. and Mikrocytos donaxi n. sp. (Ascetosporea: Mikrocytida: Mikrocytiidae), detected during important mortality events of the wedge clam Donax trunculus Linnaeus (Veneroida: Donacidae), in France between 2008 and 2011.

Background: Microcell parasites are small intracellular protozoans mostly detected in molluscs and can be associated with mortalities. In 2010 and 2011, strong increases in mortality events were reported in different wild beds of the wedge clam Donax trunculus Linnaeus, along the Atlantic coast of France and the presence of potential pathogens, including microcells, was investigated.

Methods: Clams collected in different beds showing mortality were examined by histology.

ADF/Cofilin Accelerates Actin Dynamics by Severing Filaments and Promoting Their Depolymerization at Both Ends.

Actin-depolymerizing factor (ADF)/cofilins contribute to cytoskeletal dynamics by promoting rapid actin filament disassembly. In the classical view, ADF/cofilin sever filaments, and capping proteins block filament barbed ends whereas pointed ends depolymerize, at a rate that is still debated. Here, by monitoring the activity of the three mammalian ADF/cofilin isoforms on individual skeletal muscle and cytoplasmic actin filaments, we directly quantify the reactions underpinning filament severing and depolymerization from both ends.

Profilin Interaction with Actin Filament Barbed End Controls Dynamic Instability, Capping, Branching, and Motility.

Cell motility and actin homeostasis depend on the control of polarized growth of actin filaments. Profilin, an abundant regulator of actin dynamics, supports filament assembly at barbed ends by binding G-actin. Here, we demonstrate how, by binding and destabilizing filament barbed ends at physiological concentrations, profilin also controls motility, cell migration, and actin homeostasis.

Lower jaw reconstruction and dental rehabilitation after war injuries: The experience of Paul Tessier in Iran in the late 1980s.

Iraq-Iran war resulted in more than 400,000 people requiring prolonged medical care in Iran. An international team of prominent reconstructive surgeons led by Paul Tessier, the founder of craniofacial surgery, was invited to Iran during the war by official organizations entitled to support war victims. This team provided up-to-date oral and maxillofacial rehabilitation to patients with severe trauma defects in the lower third of the face.

Paul Tessier facial reconstruction in 1970 Iran, a series of post-noma defects.

Background: Paul Tessier was a pioneering plastic surgeon who founded craniofacial surgery and had an international influence in the field of reconstructive surgery. We reviewed his techniques in the reconstruction of post-noma defects in Iran in the late 1970s.

Patients And Methods: We studied a series of 23 patients operated on by Tessier from 1974 to 1978 in Iran (property of Association Française des Chirurgiens de la Face).

Structural insight into how the human helicase subunit MCM2 may act as a histone chaperone together with ASF1 at the replication fork.

MCM2 is a subunit of the replicative helicase machinery shown to interact with histones H3 and H4 during the replication process through its N-terminal domain. During replication, this interaction has been proposed to assist disassembly and assembly of nucleosomes on DNA. However, how this interaction participates in crosstalk with histone chaperones at the replication fork remains to be elucidated.

Empty fenestration of the internal jugular vein: a rare phenomenon.

Though there are common variations of the internal jugular vein (IJV), fenestrations are extremely rare. The lateral branch of the accessory nerve classically goes through the fenestration. We report a case of an empty fenestration of the IJV that was discovered during clearance of cervical lymph nodes.

Unilateral complete articulated ossification of the stylohyoid apparatus: case report and review of the literature.

Anatomical variations of the stylohyoid apparatus are frequent. Two types can occur: an elongation of the stylohyoid ligament, from a long styloid process to a complete ossified structure connecting the skull base to the lesser horn of the hyoid bone, or the existence of supernumerary bones in the stylohyoid fibrous matrix, which sometimes resembles phalanges. These variations are in the majority of cases bilateral and symmetrical.

Spire and Formin 2 synergize and antagonize in regulating actin assembly in meiosis by a ping-pong mechanism.

In mammalian oocytes, three actin binding proteins, Formin 2 (Fmn2), Spire, and profilin, synergistically organize a dynamic cytoplasmic actin meshwork that mediates translocation of the spindle toward the cortex and is required for successful fertilization. Here we characterize Fmn2 and elucidate the molecular mechanism for this synergy, using bulk solution and individual filament kinetic measurements of actin assembly dynamics. We show that by capping filament barbed ends, Spire recruits Fmn2 and facilitates its association with barbed ends, followed by rapid processive assembly and release of Spire.

[Mandibular metastasis of a cutaneous melanoma or metachronous amelanotic melanoma of the oral cavity? A case report and literature review].

Primary and metastatic mandibular melanoma are extremely rare. We report the original case of a 55-year-old woman treated 16 years before for a cutaneous melanoma, and now presenting with a huge mandibular amelanotic melanoma. Was it an histologically different mandibular metastasis of the previous cutaneous melanoma, or a metachronous oral amelanotic melanoma?

[Can one harvest a long bone stick in the radial forearm flap? Original radioanatomical and NanoSPECT-CT Bioscan microvascular study].

Objectives: The composite radial forearm flap is a surgical option in the reconstruction of large traumatic or oncologic orofacial defects. Nevertheless, it has been criticized for its poor bone transport faculties that would make this flap insufficient in large osseous mandibular reconstructions, or for oral prosthetic rehabilitation with dental implants. What is more, the morbidity of the donor site has often been pointed.