Publications by authors named "Sabine Keppler-Ross"

Mothers contribute cytoplasmic components to their progeny in a process called maternal provisioning. Provisioning is influenced by the parental environment, but the molecular pathways that transmit environmental cues between generations are not well understood. Here, we show that, in , social cues modulate maternal provisioning to regulate gene silencing in offspring.

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During the first hours of embryogenesis, formation of higher-order heterochromatin coincides with the loss of developmental potential. Here, we examine the relationship between these two events, and we probe the processes that contribute to the timing of their onset. Mutations that disrupt histone H3 lysine 9 (H3K9) methyltransferases reveal that the methyltransferase MET-2 helps terminate developmental plasticity, through mono- and di-methylation of H3K9 (me1/me2), and promotes heterochromatin formation, through H3K9me3.

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Heterochromatin formation during early embryogenesis is timed precisely, but how this process is regulated remains elusive. We report the discovery of a histone methyltransferase complex whose nuclear accumulation and activation establish the onset of heterochromatin formation in embryos. We find that the inception of heterochromatin generation coincides with the accumulation of the histone H3 lysine 9 (H3K9) methyltransferase MET-2 (SETDB) into nuclear hubs.

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The human fungal pathogen Candida albicans causes lethal systemic infections because of its ability to grow and disseminate in a host. The C. albicans plasma membrane is essential for virulence by acting as a protective barrier and through its key roles in interfacing with the environment, secretion of virulence factors, morphogenesis, and cell wall synthesis.

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The first barrier against infection by Candida albicans involves fungal recognition and destruction by phagocytic cells of the innate immune system. It is well established that interactions between different phagocyte receptors and components of the fungal cell wall trigger phagocytosis and subsequent immune responses, but the fungal ligands mediating the initial stage of recognition have not been identified. Here, we describe a novel assay for fungal recognition and uptake by macrophages which monitors this early recognition step independently of other downstream events of phagocytosis.

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N-Linked glycosylation begins with the formation of a dolichol-linked oligosaccharide in the endoplasmic reticulum (ER). The first two steps of this pathway lead to the formation of GlcNAc(2)-PP-dolichol, whose synthesis is sequentially catalyzed by the Alg7p GlcNAc phosphotransferase and by the dimeric Alg13p/Alg14p UDP-GlcNAc transferase on the cytosolic face of the endoplasmic reticulum. Here, we show that the Alg7p, Alg13p, and Alg14p glycosyltransferases form a functional multienzyme complex.

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The ability to visualize cellular events by linking them to color or fluorescence changes has been an invaluable tool for biology. We describe a novel plasmid-borne color marker whose expression in yeast leads to purple-colored cells that are also brightly fluorescent. This dominant marker provides a useful tool for rapidly screening plasmid maintenance using a visual or fluorescence assay in both Saccharomyces cerevisiae and Candida albicans.

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N-linked glycosylation begins in the endoplasmic reticulum with the synthesis of a highly conserved dolichol-linked oligosaccharide precursor. The UDP-GlcNAc glycosyltransferase catalyzing the second sugar addition of this precursor consists in most eukaryotes of at least two subunits, Alg14 and Alg13. Alg14 is a membrane protein that recruits the soluble Alg13 catalytic subunit from the cytosol to the face of the endoplasmic reticulum (ER) membrane where this reaction occurs.

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Cystinosis is a lysosomal storage disease caused by an accumulation of insoluble cystine in the lumen of the lysosome. CTNS encodes the lysosomal cystine transporter, mutations in which manifest as a range of disorders and are the most common cause of inherited renal Fanconi syndrome. Cystinosin, the CTNS product, is highly conserved among mammals.

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