Diversification of molecular pattern recognition in bacterial NLR-like proteins.

Antiviral STANDs (Avs) are bacterial anti-phage proteins evolutionarily related to immune pattern recognition receptors of the NLR family. Type 2 Avs proteins (Avs2) were suggested to recognize the phage large terminase subunit as a signature of phage infection. Here, we show that Avs2 from Klebsiella pneumoniae (KpAvs2) can recognize several different phage proteins as signature for infection.

Genetic control over biogenic crystal morphogenesis in zebrafish.

Organisms evolve mechanisms that regulate the properties of biogenic crystals to support a wide range of functions, from vision and camouflage to communication and thermal regulation. Yet, the mechanism underlying the formation of diverse intracellular crystals remains enigmatic. Here we unravel the biochemical control over crystal morphogenesis in zebrafish iridophores.

The molecular mechanism of on-demand sterol biosynthesis at organelle contact sites.

Contact-sites are specialized zones of proximity between two organelles, essential for organelle communication and coordination. The formation of contacts between the Endoplasmic Reticulum (ER), and other organelles, relies on a unique membrane environment enriched in sterols. However, how these sterol-rich domains are formed and maintained had not been understood.

Large-scale proteomics analysis of five brain regions from Parkinson's disease patients with a GBA1 mutation.

Despite being the second most common neurodegenerative disorder, little is known about Parkinson's disease (PD) pathogenesis. A number of genetic factors predispose towards PD, among them mutations in GBA1, which encodes the lysosomal enzyme acid-β-glucosidase. We now perform non-targeted, mass spectrometry based quantitative proteomics on five brain regions from PD patients with a GBA1 mutation (PD-GBA) and compare to age- and sex-matched idiopathic PD patients (IPD) and controls.

Proteomics analysis of the brain from a Gaucher disease mouse identifies pathological pathways including a possible role for transglutaminase 1.

Gaucher disease (GD) is a lysosomal storage disorder (LSD) caused by the defective activity of acid β-glucosidase (GCase) which results from mutations in GBA1. Neurological forms of GD (nGD) can be generated in mice by intra-peritoneal injection of conduritol B-epoxide (CBE) which irreversibly inhibits GCase. Using this approach, a number of pathological pathways have been identified in mouse brain by RNAseq.

B cell class switch recombination is regulated by DYRK1A through MSH6 phosphorylation.

Protection from viral infections depends on immunoglobulin isotype switching, which endows antibodies with effector functions. Here, we find that the protein kinase DYRK1A is essential for B cell-mediated protection from viral infection and effective vaccination through regulation of class switch recombination (CSR). Dyrk1a-deficient B cells are impaired in CSR activity in vivo and in vitro.

A toolbox for systematic discovery of stable and transient protein interactors in baker's yeast.

Identification of both stable and transient interactions is essential for understanding protein function and regulation. While assessing stable interactions is more straightforward, capturing transient ones is challenging. In recent years, sophisticated tools have emerged to improve transient interactor discovery, with many harnessing the power of evolved biotin ligases for proximity labelling.

Designed High-Redox Potential Laccases Exhibit High Functional Diversity.

White-rot fungi secrete an impressive repertoire of high-redox potential laccases (HRPLs) and peroxidases for efficient oxidation and utilization of lignin. Laccases are attractive enzymes for the chemical industry due to their broad substrate range and low environmental impact. Since expression of functional recombinant HRPLs is challenging, however, iterative-directed evolution protocols have been applied to improve their expression, activity, and stability.

Amniotic fluid biomarkers predict the severity of congenital cytomegalovirus infection.

BACKGROUNDCytomegalovirus (CMV) is the most common intrauterine infection, leading to infant brain damage. Prognostic assessment of CMV-infected fetuses has remained an ongoing challenge in prenatal care, in the absence of established prenatal biomarkers of congenital CMV (cCMV) infection severity. We aimed to identify prognostic biomarkers of cCMV-related fetal brain injury.

Fatty acid transport protein 2 interacts with ceramide synthase 2 to promote ceramide synthesis.

Dihydroceramide is a lipid molecule generated via the action of (dihydro)ceramide synthases (CerSs), which use two substrates, namely sphinganine and fatty acyl-CoAs. Sphinganine is generated via the sequential activity of two integral membrane proteins located in the endoplasmic reticulum. Less is known about the source of the fatty acyl-CoAs, although a number of cytosolic proteins in the pathways of acyl-CoA generation modulate ceramide synthesis via direct or indirect interaction with the CerSs.

SUMOylation of linker histone H1 drives chromatin condensation and restriction of embryonic cell fate identity.

The fidelity of the early embryonic program is underlined by tight regulation of the chromatin. Yet, how the chromatin is organized to prohibit the reversal of the developmental program remains unclear. Specifically, the totipotency-to-pluripotency transition marks one of the most dramatic events to the chromatin, and yet, the nature of histone alterations underlying this process is incompletely characterized.

PRMT1 inhibition induces differentiation of colon cancer cells.

Differentiation therapy has been recently revisited as a prospective approach in cancer therapy by targeting the aberrant growth, and repairing the differentiation and cell death programs of cancer cells. However, differentiation therapy of solid tumors is a challenging issue and progress in this field is limited. We performed High Throughput Screening (HTS) using a novel dual multiplex assay to discover compounds, which induce differentiation of human colon cancer cells.

A Unified Linear Viscoelastic Model of the Cell Nucleus Defines the Mechanical Contributions of Lamins and Chromatin.

The cell nucleus is constantly subjected to externally applied forces. During metazoan evolution, the nucleus has been optimized to allow physical deformability while protecting the genome under load. Aberrant nucleus mechanics can alter cell migration across narrow spaces in cancer metastasis and immune response and disrupt nucleus mechanosensitivity.

CSNAP, the smallest CSN subunit, modulates proteostasis through cullin-RING ubiquitin ligases.

The cullin-RING ubiquitin E3 ligase (CRL) family consists of ~250 complexes that catalyze ubiquitylation of proteins to achieve cellular regulation. All CRLs are inhibited by the COP9 signalosome complex (CSN) through both enzymatic (deneddylation) and nonenzymatic (steric) mechanisms. The relative contribution of these two mechanisms is unclear.

Unraveling essential cellulosomal components of the () reveals an extensive reservoir of novel catalytic enzymes.

Background: () is a cellulolytic bacterium that produces the most extensive and intricate cellulosomal system known in nature. Recently, the elaborate architecture of the cellulosomal system was revealed from analysis of its genome sequence, and the first evidence regarding the interactions between its structural and enzymatic components were detected in vitro. Yet, the understanding of the cellulolytic potential of the bacterium in carbohydrate deconstruction is inextricably linked to its high-molecular-weight protein complexes, which are secreted from the bacterium.

Differential Roles of the Thylakoid Lumenal Deg Protease Homologs in Chloroplast Proteostasis.

Deg proteases are involved in protein quality control in prokaryotes. Of the three Arabidopsis () homologs, Deg1, Deg5, and Deg8, located in the thylakoid lumen, Deg1 forms a homohexamer, whereas Deg5 and Deg8 form a heterocomplex. Both Deg1 and Deg5-Deg8 were shown separately to degrade photosynthetic proteins during photoinhibition.

Degradation of Bcl-2 by XIAP and ARTS Promotes Apoptosis.

We describe a mechanism by which the anti-apoptotic B cell lymphoma 2 (Bcl-2) protein is downregulated to induce apoptosis. ARTS (Sept4_i2) is a tumor suppressor protein that promotes cell death through specifically antagonizing XIAP (X-linked inhibitor of apoptosis). ARTS and Bcl-2 reside at the outer mitochondrial membrane in living cells.