Identification and characterization of human GDF15 knockouts.

Growth differentiation factor 15 (GDF15) is a secreted protein that regulates food intake, body weight and stress responses in pre-clinical models. The physiological function of GDF15 in humans remains unclear. Pharmacologically, GDF15 agonism in humans causes nausea without accompanying weight loss, and GDF15 antagonism is being tested in clinical trials to treat cachexia and anorexia.

Replication stress promotes cell elimination by extrusion.

Cell extrusion is a mechanism of cell elimination that is used by organisms as diverse as sponges, nematodes, insects and mammals. During extrusion, a cell detaches from a layer of surrounding cells while maintaining the continuity of that layer. Vertebrate epithelial tissues primarily eliminate cells by extrusion, and the dysregulation of cell extrusion has been linked to epithelial diseases, including cancer.

Anti-tubulins DEPendably induce apoptosis.

Anti-tubulin drugs are life-saving chemotherapeutics that kill cancer cells by stabilizing or disrupting microtubules. Despite their clinical utility, the molecular mechanisms by which anti-tubulins cause apoptotic cell death remain poorly understood. It is now shown that microtubule disruption can inhibit anti-apoptotic Bcl-2 family proteins through an evolutionarily conserved signalling axis involving DEPDC1 (LET-99 in Caenorhabditis elegans) and JNK.

Xk-related protein 8 and CED-8 promote phosphatidylserine exposure in apoptotic cells.

A classic feature of apoptotic cells is the cell-surface exposure of phosphatidylserine (PtdSer) as an "eat me" signal for engulfment. We show that the Xk-family protein Xkr8 mediates PtdSer exposure in response to apoptotic stimuli. Mouse Xkr8(-/-) cells or human cancer cells in which Xkr8 expression was repressed by hypermethylation failed to expose PtdSer during apoptosis and were inefficiently engulfed by phagocytes.

Both the caspase CSP-1 and a caspase-independent pathway promote programmed cell death in parallel to the canonical pathway for apoptosis in Caenorhabditis elegans.

Caspases are cysteine proteases that can drive apoptosis in metazoans and have critical functions in the elimination of cells during development, the maintenance of tissue homeostasis, and responses to cellular damage. Although a growing body of research suggests that programmed cell death can occur in the absence of caspases, mammalian studies of caspase-independent apoptosis are confounded by the existence of at least seven caspase homologs that can function redundantly to promote cell death. Caspase-independent programmed cell death is also thought to occur in the invertebrate nematode Caenorhabditis elegans.

Programmed elimination of cells by caspase-independent cell extrusion in C. elegans.

The elimination of unnecessary or defective cells from metazoans occurs during normal development and tissue homeostasis, as well as in response to infection or cellular damage. Although many cells are removed through caspase-mediated apoptosis followed by phagocytosis by engulfing cells, other mechanisms of cell elimination occur, including the extrusion of cells from epithelia through a poorly understood, possibly caspase-independent, process. Here we identify a mechanism of cell extrusion that is caspase independent and that can eliminate a subset of the Caenorhabditis elegans cells programmed to die during embryonic development.

SPK-1, an SR protein kinase, inhibits programmed cell death in Caenorhabditis elegans.

To identify genes involved in protecting cells from programmed cell death in Caenorhabditis elegans, we performed a genetic screen to isolate mutations that cause an increase in the number of programmed cell deaths. We screened for suppressors of the cell-death defect caused by a partial loss-of-function mutation in ced-4, which encodes an Apaf-1 homolog that promotes programmed cell death by activating the caspase CED-3. We identified one extragenic ced-4 suppressor, which has a mutation in the gene spk-1.

Intramolecular cohesion of coils mediated by phenylalanine--glycine motifs in the natively unfolded domain of a nucleoporin.

The nuclear pore complex (NPC) provides the sole aqueous conduit for macromolecular exchange between the nucleus and the cytoplasm of cells. Its diffusion conduit contains a size-selective gate formed by a family of NPC proteins that feature large, natively unfolded domains with phenylalanine-glycine repeats (FG domains). These domains of nucleoporins play key roles in establishing the NPC permeability barrier, but little is known about their dynamic structure.

Rapid evolution exposes the boundaries of domain structure and function in natively unfolded FG nucleoporins.

Nucleoporins with phenylalanine-glycine repeats (FG Nups) function at the nuclear pore complex (NPC) to facilitate nucleocytoplasmic transport. In Saccharomyces cerevisiae, each FG Nup contains a large natively unfolded domain that is punctuated by FG repeats. These FG repeats are surrounded by hydrophilic amino acids (AAs) common to disordered protein domains.

Sleep deprivation effects on growth factor expression in neonatal rats: a potential role for BDNF in the mediation of delta power.

The sleeping brain differs from the waking brain in its electrophysiological and molecular properties, including the expression of growth factors and immediate early genes (IEG). Sleep architecture and homeostatic regulation of sleep in neonates is distinct from that of adults. Hence, the present study addressed the question whether the unique homeostatic response to sleep deprivation in neonates is reflected in mRNA expression of the IEG cFos, brain-derived nerve growth factor (BDNF), and basic fibroblast growth factor (FGF2) in the cortex.

Disorder in the nuclear pore complex: the FG repeat regions of nucleoporins are natively unfolded.

Nuclear transport proceeds through nuclear pore complexes (NPCs) that are embedded in the nuclear envelope of eukaryotic cells. The Saccharomyces cerevisiae NPC is comprised of 30 nucleoporins (Nups), 13 of which contain phenylalanine-glycine repeats (FG Nups) that bind karyopherins and facilitate the transport of karyopherin-cargo complexes. Here, we characterize the structural properties of S.

The Saccharomyces cerevisiae nucleoporin Nup2p is a natively unfolded protein.

Little is known about the structure of the individual nucleoporins that form eukaryotic nuclear pore complexes (NPCs). We report here in vitro physical and structural characterizations of a full-length nucleoporin, the Saccharomyces cerevisiae protein Nup2p. Analyses of the Nup2p structure by far-UV circular dichroism (CD) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, protease sensitivity, gel filtration, and sedimentation velocity experiments indicate that Nup2p is a "natively unfolded protein," belonging to a class of proteins that exhibit little secondary structure, high flexibility, and low compactness.