Molecular architecture of the endocytic TPLATE complex

Eukaryotic cells rely on endocytosis to regulate their plasma membrane proteome and lipidome. Most eukaryotic groups, except fungi and animals, have retained the evolutionary ancient TSET complex as an endocytic regulator. Unlike other coatomer complexes, structural insight into TSET is lacking. Here, we reveal the molecular architecture of plant TSET [TPLATE complex (TPC)] using an integrative structural approach. We identify crucial roles for specific TSET subunits in complex assembly and membrane interaction. Our data therefore generate fresh insight into the differences between the hexameric TSET in Dictyostelium and the octameric TPC in plants. Structural elucidation of this ancient adaptor complex represents the missing piece in the coatomer puzzle and vastly advances our functional as well as evolutionary insight into the process of endocytosis

What controls the remobilization and deformation of surficial sediment by seismic shaking? Linking lacustrine slope stratigraphy to great earthquakes in South-Central Chile

Remobilization and deformation of surficial subaqueous slope sediments create turbidites and soft sediment deformation structures, which are common features in many depositional records. Palaeoseismic studies have used seismically- induced turbidites and soft sediment deformation structures preserved in sedimentary sequences to reconstruct recurrence patterns and – in some cases – allow quantifying rupture location and magnitude of past earthquakes. However, current understanding of earthquake-triggered remobilization and deformation lacks studies targeting where these processes take place, the subaqueous slope and involving direct comparison of sedimentary fingerprint with well-documented historical earthquakes. This study investigates the sedimentary imprint of six megathrust earthquakes with varying rupture characteristics in 17 slope sediment cores from two Chilean lakes, Rinihue and Calafquen, and evaluates how it links to seismic intensity, peak ground acceleration, bracketed duration and slope angle. Centimetre-scale stratigraphic gaps ranging from ca 1 to 20 cm – caused by remobilization of surficial slope sediment – were identified using high-resolution multi-proxy core correlation of slope to basin cores, and six types of soft sediment deformation structures ranging from ca 1 to 25 cm thickness using high-resolution three-dimensional X-ray computed tomography data. Stratigraphic gaps occur on slope angles of ≥2.3°, whereas deformation already occurs from slope angle 0.2°. The thickness of both stratigraphic gaps and soft sediment deformation structures increases with slope angle, suggesting that increased gravitational shear stress promotes both surficial remobilization and deformation. Seismic shaking is the dominant trigger for surficial remobilization and deformation at the studied lakes. Total remobilization depth correlates best with bracketed duration and is highest in both lakes for the strongest earthquakes (Mw ca 9.5). In lake Rinihue, soft sediment deformation structure thickness and type correlate best with peak ground acceleration providing the first field-based evidence of progressive soft sediment deformation structure development with increasing peak ground acceleration for soft sediment deformation structures caused by Kelvin-Helmholtz instability. The authors propose that long duration and low frequency content of seismic shaking favours surficial remobilization, whereas ground motion amplitude controls Kelvin-Helmholtz instability-related soft sediment deformation structure development

The endocytic TPLATE complex internalizes ubiquitinated plasma membrane cargo

Endocytosis controls the perception of stimuli by modulating protein abundance at the plasma membrane. In plants, clathrin-mediated endocytosis is the most prominent internalization pathway and relies on two multimeric adaptor complexes, the AP-2 and the TPLATE complex (TPC). Ubiquitination is a well-established modification triggering endocytosis of cargo proteins, but how this modification is recognized to initiate the endocytic event remains elusive. Here, we show that TASH3, one of the large subunits of TPC, recognizes ubiquitinated cargo at the plasma membrane via its SH3 domain-containing appendage. TASH3 lacking this evolutionary specific appendage modification allows TPC formation, but the plants show severely reduced endocytic densities, which correlates with reduced endocytic flux. Moreover, comparative plasma membrane proteomics identified differential accumulation of multiple ubiquitinated cargo proteins for which we confirm altered trafficking. Our findings position TPC as a key player for ubiquitinated cargo internalization, allowing future identification of target proteins under specific stress conditions

DynamIA: dynamic hardware reconfiguration in industrial applications

This paper presents the work that will be done in the research project “DynamIA: Dynamic Hardware Reconfiguration in Industrial Applications”. The project focuses on transferring knowledge on partial and dynamic reconfiguration of FPGAs from the academic partners to small and medium enterprises (SMEs), because the success stories on partial and dynamic reconfiguration were mainly only realized in large companies with a substantial amount of R&D activities. The reason is that the technology is still perceived as being difficult to adopt and expensive in terms of NRE costs. Therefore, the goal of the DynamIA project is two-fold. (1) It develops a number of use cases and guidelines in different application domains, tailored to the activities of the SMEs in the user group and in the broader target group. These use cases demonstrate a number of benefits of partial and dynamic FPGA reconfiguration, namely a faster startup, a faster design cycle and a lower occupation of resources leading to a lower static power consumption. (2) It develops a low-cost, vendor-independent emulation environment for dynamic and partial reconfiguration, which is non-existing in commercial and academic EDA tools. Another benefit of this emulation environment is that it can also be used for static designs. This allows SMEs to have a low-cost emulation environment for their applications instead of developing their own emulation environment manually (which is very time-consuming) or buying big cost-intensive commercial emulators

Increased Red Cell KCNN4 Activity in Sporadic Hereditary Xerocytosis Associated With Enhanced Single Channel Pressure Sensitivity of PIEZO1 Mutant V598M

Supplemental Digital Content is available in the text

TPLATE complex dependent endocytosis is required for shoot apical meristem maintenance by attenuating CLAVATA1 signaling

Abstract Endocytosis regulates the turnover of cell surface localized receptors, which are crucial for plants to sense and rapidly respond to both endogenous and environmental stimuli. The evolutionarily ancient TPLATE complex (TPC) plays an essential role in clathrin-mediated endocytosis (CME) in Arabidopsis plants. Knockout or strong knockdown of single TPC subunits causes male sterility and seedling lethality phenotypes, complicating analysis of the roles of TPC during plant development. Partially functional alleles of TPC subunits however only cause very mild developmental deviations. Here, we took advantage of the recently reported partially functional TPLATE allele, WDXM2, to investigate a role for TPC-dependent endocytosis in receptor-mediated signalling. We discovered that reduced TPC-dependent endocytosis confers a hypersensitivity to very low doses of CLAVATA3 (CLV3) peptide signalling. This hypersensitivity correlated with the abundance of the CLV3 receptor protein kinase CLAVATA1 (CLV1) at the plasma membrane. Genetic analysis and live-cell imaging revealed that TPC-dependent regulation of CLV3-dependent internalization of CLV1 from the plasma membrane is required for CLV3 function in the shoot. Our findings provide evidence that clathrin-mediated endocytosis of CLV1 is a mechanism to dampen CLV3-mediated signaling during plant development

TPLATE complex‐dependent endocytosis attenuates CLAVATA1 signaling for shoot apical meristem maintenance

International audienceEndocytosis regulates the turnover of cell surface localized receptors, which are crucial for plants to rapidly respond to stimuli. The evolutionary ancient TPLATE complex (TPC) plays an essential role in endocytosis in Arabidopsis plants. Knockout or knockdown of single TPC subunits causes male sterility and seedling lethality phenotypes, complicating analysis of the roles of TPC during plant development. Partially functional alleles of TPC subunits however only cause mild developmental deviations. Here, we took advantage of the partially functional TPLATE allele, WDXM2, to investigate a role for TPC‐dependent endocytosis in receptor‐mediated signaling. We discovered that reduced TPC‐dependent endocytosis confers a hypersensitivity to very low doses of CLAVATA3 peptide signaling. This hypersensitivity correlated with the abundance of the CLAVATA3 receptor protein kinase CLAVATA1 at the plasma membrane. Genetic and biochemical analysis as well as live‐cell imaging revealed that TPC‐dependent regulation of CLAVATA3‐dependent internalization of CLAVATA1 from the plasma membrane is required for shoot stem cell homeostasis. Our findings provide evidence that TPC‐mediated endocytosis and degradation of CLAVATA1 is a mechanism to dampen CLAVATA3‐mediated signaling during plant development

Plant AtEH/Pan1 proteins drive autophagosome formation at ER-PM contact sites with actin and endocytic machinery

The Arabidopsis EH proteins (AtEH1/Pan1 and AtEH2/Pan1) are components of the endocytic TPLATE complex (TPC) which is essential for endocytosis. Both proteins are homologues of the yeast ARP2/3 complex activator, Pan1p. Here, we show that these proteins are also involved in actin cytoskeleton regulated autophagy. Both AtEH/Pan1 proteins localise to the plasma membrane and autophagosomes. Upon induction of autophagy, AtEH/Pan1 proteins recruit TPC and AP-2 subunits, clathrin, actin and ARP2/3 proteins to autophagosomes. Increased expression of AtEH/Pan1 proteins boosts autophagosome formation, suggesting independent and redundant pathways for actin-mediated autophagy in plants. Moreover, AtEHs/Pan1-regulated autophagosomes associate with ER-PM contact sites (EPCS) where AtEH1/Pan1 interacts with VAP27-1. Knock-down expression of either AtEH1/Pan1 or VAP27-1 makes plants more susceptible to nutrient depleted conditions, indicating that the autophagy pathway is perturbed. In conclusion, we identify the existence of an autophagy-dependent pathway in plants to degrade endocytic components, starting at the EPCS through the interaction among AtEH/Pan1, actin cytoskeleton and the EPCS resident protein VAP27-1