3,500 research outputs found
The phosphoinositide-associated protein Rush hour regulates endosomal trafficking in<i>Drosophila</i>
No full textEndocytosis regulates multiple cellular processes, including the protein composition of the plasma membrane, intercellular signaling, and cell polarity. We have identified the highly conserved protein Rush hour (Rush) and show that it participates in the regulation of endocytosis. Rush localizes to endosomes via direct binding of its FYVE (Fab1p, YOTB, Vac1p, EEA1) domain to phosphatidylinositol 3-phosphate. Rush also directly binds to Rab GDP dissociation inhibitor (Gdi), which is involved in the activation of Rab proteins. Homozygous rush mutant flies are viable but show genetic interactions with mutations in Gdi, Rab5, hrs, and carnation, the fly homologue of Vps33. Overexpression of Rush disrupts progression of endocytosed cargo and increases late endosome size. Lysosomal marker staining is decreased in Rush-overexpressing cells, pointing to a defect in the transition between late endosomes and lysosomes. Rush also causes formation of endosome clusters, possibly by affecting fusion of endosomes via an interaction with the class C Vps/homotypic fusion and vacuole protein-sorting (HOPS) complex. These results indicate that Rush controls trafficking from early to late endosomes and from late endosomes to lysosomes by modulating the activity of Rab proteins.</jats:p
PP2A Antagonizes Phosphorylation of Bazooka by PAR-1 to Control Apical-Basal Polarity in Dividing Embryonic Neuroblasts
No full textSummaryBazooka/Par-3 (Baz) is a key regulator of cell polarity in epithelial cells and neuroblasts (NBs). Phosphorylation of Baz by PAR-1 and aPKC is required for its function in epithelia, but little is known about the dephosphorylation mechanisms that antagonize the activities of these kinases or about the relevance of Baz phosphorylation for NB polarity. We found that protein phosphatase 2A (PP2A) binds to Baz via its structural A subunit. By using phospho-specific antibodies, we show that PP2A dephosphorylates Baz at the conserved serine residue 1085 and thereby antagonizes the kinase activity of PAR-1. Loss of PP2A function leads to complete reversal of polarity in NBs, giving rise to an “upside-down” polarity phenotype. Overexpression of PAR-1 or Baz, or mutation of 14-3-3 proteins that bind phosphorylated Baz, causes essentially the same phenotype, indicating that the balance of PAR-1 and PP2A effects on Baz phosphorylation determines NB polarity
protein related to vertebrate HURP, is required for the attachment of centrosomes to the mitotic spindle during syncytial nuclear divisions
No full textThe formation of the mitotic spindle is controlled by the microtubule organizing activity of the centrosomes and by the effects of chromatin-associated Ran-GTP on the activities of spindle assembly factors. In this study we show that Mars, a Drosophila protein with sequence similarity to vertebrate hepatoma upregulated protein (HURP), is required for the attachment of the centrosome to the mitotic spindle. More than 80% of embryos derived from mars mutant females do not develop properly due to severe mitotic defects during the rapid nuclear divisions in early embryogenesis. Centrosomes frequently detach from spindles and from the nuclear envelope and nucleate astral microtubules in ectopic positions. Consistent with its function in spindle organization, Mars localizes to nuclei in interphase and associates with the mitotic spindle, in particular with the spindle poles, during mitosis. We propose that Mars is an important linker between the spindle and the centrosomes that is required for proper spindle organization during the rapid mitotic cycles in early embryogenesis.Deutsche Forschungsgemeinschaft [SFB 590, TP A2, WO 584/4-1, 42
Windei, the Drosophila homolog of mAM/MCAF1, is an essential cofactor of the H3K9 methyl transferase dSETDB1/Eggless in germ line development.
No full textThe epigenetic regulation of gene expression by the covalent modification of histones is a fundamental mechanism required for the proper differentiation of germ line cells during development. Trimethylation of histone 3 lysine 9 (H3K9me3) leads to chromatin silencing and the formation of heterochromatin by recruitment of heterochromatin protein 1 (HP1). dSETDB1/Eggless (Egg), the ortholog of the human methyltransferase SETDB1, is the only essential H3K9 methyltransferase in Drosophila and is required for H3K9 trimethylation in the female germ line. Here we show that Windei (Wde), the Drosophila homolog of mouse mAM and human MCAF1, is an essential cofactor of Egg required for its nuclear localization and function in female germ line cells. By deletion analysis combined with coimmunoprecipitation, we have identified the protein regions in Wde and Egg that are necessary and sufficient for the interaction between the two proteins. We furthermore identified a region of Egg that gets covalently modified by SUMOylation, which may facilitate the formation of higher order chromatin-modifying complexes. Together with Egg, Wde localizes to euchromatin, is enriched on chromosome 4, and binds to the Painting of fourth (POF) protein. Our data provide the first genetic and phenotypic analysis of a mAM/MCAF1 homolog in a model organism and demonstrate its essential function in the survival of germ line cells
Diane Zinna, 45th Annual ODU Literary Festival
No full textDiane Zinna is the author of THE ALL-NIGHT SUN (Random House, 2020) which was longlisted for The Center for Fiction\u27s First Novel Prize and the Cabell First Novelist Award. She received her MFA from the University of Florida and was the longtime membership director for AWP, The Association of Writers & Writing Programs. There, she created the Writer to Writer Mentorship Program, helping to match more than six hundred writers over twelve seasons. She is also the creator of Grief Writing Sundays, a popular writing class on telling difficult stories that has met every week since the start of the pandemic. Diane is the recipient of an ArtsFairfax Artist Grant, and beginning Fall 2022, she will be the Darden Professor of Creative Writing at Old Dominion University. Her work has appeared or is forthcoming at Electric Literature, LiteraryHub, Brevity, Monkeybicycle, and Eat, Darling, Eat. Diane lives in Fairfax, Virginia, with her husband, daughter, and doodle
Author Diane Glancy discusses her first movie project and reads from a journal she is keeping about her experiences as a novice movie maker
No full textNoted author Diane Glancy discusses her first movie project and reads from a journal she is keeping about her experiences as a novice movie maker. After showing a clip from the still unfinished movie (not included here), she takes questions from the audience. Introduced by MSU Anthropology Professor Susan Applegate Krouse. Part of the Michigan State University Libraries' Michigan Writers Series
Leslie Behm interviews science fiction writer Diane Carey
No full textAuthor Diane Carey talks about how she came to write science fiction books for the "Star Trek" series, about the business of freelance writing, being a dependable writer, and being fortunate to have found a genre which she enjoys and is in demand. Carey is interviewed by Leslie Behm for the Michigan State University Libraries' Michigan Science Fiction Writers Series
Diane Wakoski, 4th Annual ODU Literary Festival
No full textOne of the two or three most important poets of her generation in America, wrote Hayden Carruth about the extremely prolific and talented Diane Wakoski. Author of more than a dozen full-length collections and as many chapbooks, Wakoski is considered one of the most poetically daring writers on the American scene. While she frequently writes about the difficulty of being a woman in an age of changing values, her range encompasses an array of contemporary subject matters and themes. Since 1962, when her first book of poetry appeared, Wakoski has continued to draw her ever-growing readership into the complex world created by her vision
Diane Ackerman, 15th Annual ODU Literary Festival
No full textDiane Ackerman, poet and nature writer, has cavorted with whales in Argentina, studied bats in the deserts of Texas, and scouted out rare albatrosses on Japan\u27s Torishima Island. Her non-fiction bestseller, A Natural History of the Senses, is a meticulously researched celebration of hearing, vision, smell, taste and touch. Her Jaguar of Sweet Laughter: New and Selected Poems was named a Notable Book of the Year in 1991 by the New York Times Book Review. She is also the author of Reverse Thunder, a dramatic poem on the life of a sixteenth century Mexican nun, Sister Juana Ines de la Cruz, from which the staged reading for the Literary Arts Festival has been adaped
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