Search results for "Vesicular Transport"
showing 5 items of 55 documents
PHD3 regulates EGFR internalization and signalling in tumours
2014
Tumours exploit their hypoxic microenvironment to induce a more aggressive phenotype, while curtailing the growth-inhibitory effects of hypoxia through mechanisms that are poorly understood. The prolyl hydroxylase PHD3 is regulated by hypoxia and plays an important role in tumour progression. Here we identify PHD3 as a central regulator of epidermal growth factor receptor (EGFR) activity through the control of EGFR internalization to restrain tumour growth. PHD3 controls EGFR activity by acting as a scaffolding protein that associates with the endocytic adaptor Eps15 and promotes the internalization of EGFR. In consequence, loss of PHD3 in tumour cells suppresses EGFR internalization and hy…
The Synapse-Like Interaction between Chloroplast, dictyosome, and Other Cell Compartments during Increased Ethylene Production in Leaves of Rye (Seca…
2000
Rye (Secale cereale L.) plants were treated with an ethylene releaser ethephon (2-chloroethylphosphonic acid) in concentration of 4×10−2 M. We studied electron microscopically, if and how chloroplasts interact with well-documented sites of ethylene production/binding, i.e., with endoplasmic reticulum, dictyosomes, mitochondria, plasma membrane, and tonoplast. During the sharp increase of ethylene synthesis in mesophyll cells of rye leaves, the direct local continguity of chloroplast envelope or envelope protrusions with the above mentioned cell compartments was typical. Moreover, a large number and diversity of versatile chloroplast-dictyosome associations were conspicuous, in which both th…
Endoplasmic Reticulum stress reduces COPII vesicle formation and modifies Sec23a cycling at ERESs
2013
AbstractExit from the Endoplasmic Reticulum (ER) of newly synthesized proteins is mediated by COPII vesicles that bud from the ER at the ER Exit Sites (ERESs). Disruption of ER homeostasis causes accumulation of unfolded and misfolded proteins in the ER. This condition is referred to as ER stress. Previously, we demonstrated that ER stress rapidly impairs the formation of COPII vesicles. Here, we show that membrane association of COPII components, and in particular of Sec23a, is impaired by ER stress-inducing agents suggesting the existence of a dynamic interplay between protein folding and COPII assembly at the ER.
Immunoelectron Microscopy of Vesicle Transport to the Primary Cilium of Photoreceptor Cells
2009
Cilia are organelles of high structural complexity. Since the biosynthetic machinery is absent from cilia all their molecular components must be synthesized in organelles of the cytoplasm and subsequently transported to the cilium. Ciliary cargos are thought to be translocated in the membrane of transport vesicles or association with these vesicles to the base of the cilium where the vesicles fuse with the periciliary target membrane for further delivery of their cargo into the ciliary compartment by the intraflagellar transport (IFT). Here we describe a modified preembedding labeling method as an alternative technique to conventional postembedding methods eligible for analyses of ciliary c…
Huntingtin controls neurotrophic support and survival of neurons by enhancing BDNF vesicular transport along microtubules.
2004
AbstractPolyglutamine expansion (polyQ) in the protein huntingtin is pathogenic and responsible for the neuronal toxicity associated with Huntington's disease (HD). Although wild-type huntingtin possesses antiapoptotic properties, the relationship between the neuroprotective functions of huntingtin and pathogenesis of HD remains unclear. Here, we show that huntingtin specifically enhances vesicular transport of brain-derived neurotrophic factor (BDNF) along microtubules. Huntingtin-mediated transport involves huntingtin-associated protein-1 (HAP1) and the p150Glued subunit of dynactin, an essential component of molecular motors. BDNF transport is attenuated both in the disease context and b…