Tensin-2 interactomics reveals interaction with GAPDH and a phosphorylation-mediated regulatory role in glycolysis.

Integrin adaptor proteins, like tensin-2, are crucial for cell adhesion and signaling. However, the function of tensin-2 beyond localizing to focal adhesions remain poorly understood. We utilized proximity-dependent biotinylation and Strep-tag affinity proteomics to identify interaction partners of tensin-2 in Flp-In 293 T-REx cells.

Talin-1 variants associated with spontaneous coronary artery dissection (SCAD) highlight how even subtle changes in multi-functional scaffold proteins can manifest in disease.

Variants of talin-1 (TLN1) have recently been linked with spontaneous coronary artery dissection (SCAD) a condition where a tear can form in the wall of a heart artery necessitating immediate medical care. One talin-1 variant, A2013T, has an extensive familial pedigree of SCAD, which led to the screening for, and identification of, further talin-1 variants in SCAD patients. Here we evaluated these variants with commonly used pathogenicity prediction tools and found it challenging to reliably classify SCAD-associated variants, even A2013T where the evidence of a causal role is strong.

Progression of herpesvirus infection remodels mitochondrial organization and metabolism.

Viruses target mitochondria to promote their replication, and infection-induced stress during the progression of infection leads to the regulation of antiviral defenses and mitochondrial metabolism which are opposed by counteracting viral factors. The precise structural and functional changes that underlie how mitochondria react to the infection remain largely unclear. Here we show extensive transcriptional remodeling of protein-encoding host genes involved in the respiratory chain, apoptosis, and structural organization of mitochondria as herpes simplex virus type 1 lytic infection proceeds from early to late stages of infection.

Visible Light-Induced Specific Protein Reaction Delineates Early Stages of Cell Adhesion.

Light is well-established for control of bond breakage but not for control of specific bond formation in complex environments. We previously engineered the diffusion-limited reactivity of the SpyTag003 peptide with its protein partner SpyCatcher003 through spontaneous isopeptide bond formation. This system enables precise and irreversible assembly of biological building blocks with applications from biomaterials to vaccines.

Visible light-induced specific protein reaction delineates early stages of cell adhesion.

Light is well established for control of bond breakage, but not for control of specific bond formation in complex environments. We previously engineered diffusion-limited reactivity of SpyTag003 peptide with its protein partner SpyCatcher003 through spontaneous transamidation. This system enables precise and irreversible assembly of biological building blocks, with applications from biomaterials to vaccines.

Talin variant P229S compromises integrin activation and associates with multifaceted clinical symptoms.

Adhesion of cells to the extracellular matrix (ECM) must be exquisitely coordinated to enable development and tissue homeostasis. Cell-ECM interactions are regulated by multiple signalling pathways that coordinate the activation state of the integrin family of ECM receptors. The protein talin is pivotal in this process, and talin's simultaneous interactions with the cytoplasmic tails of the integrins and the plasma membrane are essential to enable robust, dynamic control of integrin activation and cell-ECM adhesion.

Avidin-Conjugated Nanofibrillar Cellulose Hydrogel Functionalized with Biotinylated Fibronectin and Vitronectin Promotes 3D Culture of Fibroblasts.

The future success of physiologically relevant three-dimensional (3D) cell/tissue models is dependent on the development of functional biomaterials, which can provide a well-defined 3D environment instructing cellular behavior. To establish a platform to produce tailored hydrogels, we conjugated avidin (Avd) to anionic nanofibrillar cellulose (aNFC) and demonstrated the use of the resulting Avd-NFC hydrogel for 3D cell culture, where Avd-NFC allows easy functionalization biotinylated molecules. Avidin was successfully conjugated to nanocellulose and remained functional, as demonstrated by electrophoresis and titration with fluorescent biotin.

Extrusion-Based Bioprinting of Multilayered Nanocellulose Constructs for Cell Cultivation Using Freezing and Preprint CaCl Cross-Linking.

Extrusion-based bioprinting with a preprint cross-linking agent and an cooling stage provides a versatile method for the fabrication of 3D structures for cell culture. We added varying amounts of calcium chloride as a precross-linker into native nanofibrillated cellulose (NFC) hydrogel prior to 3D bioprinting to fabricate structurally stable multilayered constructs without the need for a separate cross-linking bath. To further enhance their stability, we bioprinted the multilayered structures onto an temperature-controlled printing stage at 25, 0, and -10 °C.

Cancer associated talin point mutations disorganise cell adhesion and migration.

Talin-1 is a key component of the multiprotein adhesion complexes which mediate cell migration, adhesion and integrin signalling and has been linked to cancer in several studies. We analysed talin-1 mutations reported in the Catalogue of Somatic Mutations in Cancer database and developed a bioinformatics pipeline to predict the severity of each mutation. These predictions were then assessed using biochemistry and cell biology experiments.

Approaching infinite affinity through engineering of peptide-protein interaction.

Much of life's complexity depends upon contacts between proteins with precise affinity and specificity. The successful application of engineered proteins often depends on high-stability binding to their target. In recent years, various approaches have enabled proteins to form irreversible covalent interactions with protein targets.

Human Enterovirus Group B Viruses Rely on Vimentin Dynamics for Efficient Processing of Viral Nonstructural Proteins.

We report that several viruses from the human enterovirus group B cause massive vimentin rearrangements during lytic infection. Comprehensive studies suggested that viral protein synthesis was triggering the vimentin rearrangements. Blocking the host cell vimentin dynamics with β, β'-iminodipropionitrile (IDPN) did not significantly affect the production of progeny viruses and only moderately lowered the synthesis of structural proteins such as VP1.

Slow Infection due to Lowering the Amount of Intact versus Empty Particles Is a Characteristic Feature of Coxsackievirus B5 Dictated by the Structural Proteins.

Enterovirus B species typically cause a rapid cytolytic infection leading to efficient release of progeny viruses. However, they are also capable of persistent infections in tissues, which are suggested to contribute to severe chronic states such as myocardial inflammation and type 1 diabetes. In order to understand the factors contributing to differential infection strategies, we constructed a chimera by combining the capsid proteins from fast-cytolysis-causing echovirus 1 (EV1) with nonstructural proteins from coxsackievirus B5 (CVB5), which shows persistent infection in RD cells.

Talin-mediated force transmission and talin rod domain unfolding independently regulate adhesion signaling.

Talin protein is one of the key components in integrin-mediated adhesion complexes. Talins transmit mechanical forces between β-integrin and actin, and regulate adhesion complex composition and signaling through the force-regulated unfolding of talin rod domain. Using modified talin proteins, we demonstrate that these functions contribute to different cellular processes and can be dissected.

Echovirus 1 internalization negatively regulates epidermal growth factor receptor downregulation.

We have demonstrated previously that the human picornavirus Echovirus 1 (EV1) triggers an infectious internalization pathway that follows closely, but seems to stay separate, from the epidermal growth factor receptor (EGFR) pathway triggered by epidermal growth factor (EGF). Here, we confirmed by using live and confocal microscopy that EGFR and EV1 vesicles are following intimately each other but are distinct entities with different degradation kinetics. We show here that despite being sorted to different pathways and located in distinct endosomes, EV1 inhibits EGFR downregulation.

Infectious Entry Pathway of Enterovirus B Species.

Enterovirus B species (EV-B) are responsible for a vast number of mild and serious acute infections. They are also suspected of remaining in the body, where they cause persistent infections contributing to chronic diseases such as type I diabetes. Recent studies of the infectious entry pathway of these viruses revealed remarkable similarities, including non-clathrin entry of large endosomes originating from the plasma membrane invaginations.

6-o- and N-sulfated syndecan-1 promotes baculovirus binding and entry into Mammalian cells.

Baculoviruses are insect-specific viruses commonly found in nature. They are not able to replicate in mammalian cells but can transduce them when equipped with an appropriate mammalian cell active expression cassette. Although the viruses have been studied in several types of mammalian cells from different origins, the receptor that baculovirus uses to enter or interact with mammalian cells has not yet been identified.

Cell susceptibility to baculovirus transduction and echovirus infection is modified by protein kinase C phosphorylation and vimentin organization.

Some cell types are more susceptible to viral gene transfer or virus infection than others, irrespective of the number of viral receptors or virus binding efficacy on their surfaces. In order to characterize the cell-line-specific features contributing to efficient virus entry, we studied two cell lines (Ea.hy926 and MG-63) that are nearly nonpermissive to insect-specific baculovirus (BV) and the human enterovirus echovirus 1 (EV1) and compared their characteristics with those of a highly permissive (HepG2) cell line.

Clathrin-independent entry of baculovirus triggers uptake of E. coli in non-phagocytic human cells.

The prototype baculovirus, Autographa californica multiple nucleopolyhedrovirus, an insect pathogen, holds great potential as a gene therapy vector. To develop transductional targeting and gene delivery by baculovirus, we focused on characterizing the nature and regulation of its uptake in human cancer cells. Baculovirus entered the cells along fluid-phase markers from the raft areas into smooth-surfaced vesicles devoid of clathrin.