2,012 research outputs found
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Sec24 phosphorylation regulates COPII vesicles during autophagy
No full textMacroautophagy is a process of bulk degradation initiated during cellular starvation or stress. When macroautophagy (hereafter referred to as autophagy) is induced there is a rapid upregulation in the formation of autophagosomes; double membrane vesicles, which engulf cytoplasmic materials and organelles. After formation, autophagosomes fuse with the vacuole releasing their contents for degradation, which is essential to maintain homeostasis during nutrient deprivation. Although the membrane source and trafficking events leading to autophagosome formation are poorly understood, recent findings have implicated endoplasmic reticulum (ER)-derived COPII vesicles in autophagosome biogenesis. During nutrient rich conditions, COPII vesicles work on the secretory pathway by transporting cargo from the ER to the Golgi. How the function of COPII vesicles is regulated to balance their roles in secretion and autophagy is unclear. Moreover, the molecular mechanism of how COPII vesicles recognize autophagy machinery to aid in autophagosome formation is unknown. The current understanding of the function of COPII vesicles and other parts of the secretory pathway in autophagy is discussed in Chapter 1. The work in this dissertation examines how phosphorylation of Sec24, a subunit of the inner COPII coat, regulates autophagosome formation. In Chapter 2 we rule out a major role for Sec24 phosphorylation in regulating the secretory pathway. We next screened for Sec24 phosphorylation sites that are required for autophagy and not ER-Golgi transport. This analysis identified a patch of conserved phosphorylation sites that are required for autophagosome formation during starvation. Phosphorylation of these residues regulates autophagosome frequency and enhances the interaction of the COPII coat with Atg9, a key regulator of autophagosome initiation. Chapter 3 discusses the role of the serine/threonine kinase Hrr25 in regulating the Sec24-Atg9 interaction through Sec24 phosphorylation. Chapter 4 discusses the interacting domains of Uso1, a long coil-coiled tether that links COPII vesicles to the Golgi on the secretory pathway. Chapter 5 places these findings into the broader context of COPII vesicle trafficking and autophagosome formation. Additionally, this final chapter gives recommendations for future experiments to further our knowledge of the membrane rearrangements required for autophagosome initiation
sj-docx-1-sci-10.1177_00368504241242276 - Supplemental material for Harnessing technology to improve sleep in frontline healthcare workers: A pilot study of electronic noise-masking earbuds on subjective and objective sleep measures
No full textSupplemental material, sj-docx-1-sci-10.1177_00368504241242276 for Harnessing technology to improve sleep in frontline healthcare workers: A pilot study of electronic noise-masking earbuds on subjective and objective sleep measures by Heinrich C Haller, Susan L Moore, Katherine K Green, Rachel L Johnson, Mary D Sammel, C Neill Epperson and Andrew M Novick in Science Progress</p
sj-docx-2-sci-10.1177_00368504241242276 - Supplemental material for Harnessing technology to improve sleep in frontline healthcare workers: A pilot study of electronic noise-masking earbuds on subjective and objective sleep measures
No full textSupplemental material, sj-docx-2-sci-10.1177_00368504241242276 for Harnessing technology to improve sleep in frontline healthcare workers: A pilot study of electronic noise-masking earbuds on subjective and objective sleep measures by Heinrich C Haller, Susan L Moore, Katherine K Green, Rachel L Johnson, Mary D Sammel, C Neill Epperson and Andrew M Novick in Science Progress</p
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Actin assembly at sites of contact between the cortical ER and endocytic pits promotes ER autophagy.
No full textA recent screen of the Saccharomyces cerevisiae deletion library implicated End3 in autophagy of the endoplasmic reticulum (ER). Together with Pan1, End3 coordinates endocytic site initiation with the localized assembly of branching actin filaments that promotes invagination of endocytic pits. Oxysterol binding proteins function as an inter-organelle bridge by interacting with VAP proteins on the cortical ER and type I myosins on the endocytic pit. These proteins not only promote localized actin assembly at contact sites, they are required for ER autophagy as well. We propose that localized actin polymerization can push the edge of an ER sheet from the cell cortex toward the site of autophagosome assembly near the vacuole
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Autophagy of the ER requires actin assembly driven by the interaction of ER with endocytic pits.
No full textAutophagy of the cortical ER in budding yeast was unexpectedly found to require End3, a component of the endocytic machinery that promotes the assembly of actin at endocytic pits on the plasma membrane. The cortical ER transiently interacts with invaginating endocytic pits through a linkage consisting of VAP proteins, oxysterol binding proteins and type I myosins. These proteins are required for actin assembly and for autophagy of the ER. Assembly of actin at these contact sites may direct the movement of ER away from the cortex towards sites of autophagosome assembly
ER network formation requires a balance of the dynamin-like GTPase Sey1p and the Lunapark family member Lnp1p
No full textDifferent polarisome components play distinct roles in Slt2p-regulated cortical ER inheritance in Saccharomyces cerevisiae.
No full textPtc1p, a type 2C protein phosphatase, is required for a late step in cortical endoplasmic reticulum (cER) inheritance in Saccharomyces cerevisiae. In ptc1Δ cells, ER tubules migrate from the mother cell and contact the bud tip, yet fail to spread around the bud cortex. This defect results from the failure to inactivate a bud tip-associated pool of the cell wall integrity mitogen-activated protein kinase, Slt2p. Here we report that the polarisome complex affects cER inheritance through its effects on Slt2p, with different components playing distinct roles: Spa2p and Pea2p are required for Slt2p retention at the bud tip, whereas Bni1p, Bud6p, and Sph1p affect the level of Slt2p activation. Depolymerization of actin relieves the ptc1Δ cER inheritance defect, suggesting that in this mutant the ER becomes trapped on the cytoskeleton. Loss of Sec3p also blocks ER inheritance, and, as in ptc1Δ cells, this block is accompanied by activation of Slt2p and is reversed by depolymerization of actin. Our results point to a common mechanism for the regulation of ER inheritance in which Slt2p activity at the bud tip controls the association of the ER with the actin-based cytoskeleton
Il milanese Francesco Ellio traduttore del 'Persiles' di Cervantes (1626)
No full textThe essay presents a research around the figure of the Milanese poet Francesco Ellio,
who lived in Milan in the early seventeenth century and is so far known for being the
author of idylls. In this paper Ellio, whose dense network of contacts and relationships in the
Lombard city is gathered, is studied because he is the author of the first Italian translation of
Cervantes’ Perciles, the last masterpiece of the Hispanic genius, published in 1617. The translation
was edited in Venice for the printer Fontana in 1626, placing itself among the last traces
of Ellio’s life, and will remain the only one in Italian until the nineteenth century
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