scispace - formally typeset
Search or ask a question
Journal ArticleDOI

Phospholipase D Stimulates Release of Nascent Secretory Vesicles from the trans-Golgi Network

11 Aug 1997-Journal of Cell Biology (The Rockefeller University Press)-Vol. 138, Iss: 3, pp 495-504
TL;DR: It is demonstrated that immunoaffinity-purified human PLD1 stimulated nascent secretory vesicle budding from the TGN and ARF-1 stimulated endogenous PLD activity in Golgi membranes approximately threefold and this activation correlated with its enhancement of vesicles budding.
Abstract: Phospholipase D (PLD) is a phospholipid hydrolyzing enzyme whose activation has been implicated in mediating signal transduction pathways, cell growth, and membrane trafficking in mammalian cells. Several laboratories have demonstrated that small GTP-binding proteins including ADP-ribosylation factor (ARF) can stimulate PLD activity in vitro and an ARF-activated PLD activity has been found in Golgi membranes. Since ARF-1 has also been shown to enhance release of nascent secretory vesicles from the TGN of endocrine cells, we hypothesized that this reaction occurred via PLD activation. Using a permeabilized cell system derived from growth hormone and prolactin-secreting pituitary GH3 cells, we demonstrate that immunoaffinity-purified human PLD1 stimulated nascent secretory vesicle budding from the TGN approximately twofold. In contrast, a similarly purified but enzymatically inactive mutant form of PLD1, designated Lys898Arg, had no effect on vesicle budding when added to the permeabilized cells. The release of nascent secretory vesicles from the TGN was sensitive to 1% 1-butanol, a concentration that inhibited PLD-catalyzed formation of phosphatidic acid. Furthermore, ARF-1 stimulated endogenous PLD activity in Golgi membranes approximately threefold and this activation correlated with its enhancement of vesicle budding. Our results suggest that ARF regulation of PLD activity plays an important role in the release of nascent secretory vesicles from the TGN.

Content maybe subject to copyright    Report

Citations
More filters
Journal ArticleDOI
TL;DR: This review summarizes and evaluates current information about how secretory proteins are thought to be sorted for the regulated secretory pathway and how these activities are positioned with respect to other post-Golgi sorting events that must occur in parallel.
Abstract: Secretory granules are specialized intracellular organelles that serve as a storage pool for selected secretory products. The exocytosis of secretory granules is markedly amplified under physiologically stimulated conditions. While granules have been recognized as post-Golgi carriers for almost 40 years, the molecular mechanisms involved in their formation from the trans-Golgi network are only beginning to be defined. This review summarizes and evaluates current information about how secretory proteins are thought to be sorted for the regulated secretory pathway and how these activities are positioned with respect to other post-Golgi sorting events that must occur in parallel. In the first half of the review, the emerging role of immature secretory granules in protein sorting is highlighted. The second half of the review summarizes what is known about the composition of granule membranes. The numerous similarities and relatively limited differences identified between granule membranes and other vesicular carriers that convey products to and from the plasmalemma, serve as a basis for examining how granule membrane composition might be established and how its unique functions interface with general post-Golgi membrane traffic. Studies of granule formation in vitro offer additional new insights, but also important challenges for future efforts to understand how regulated secretory pathways are constructed and maintained.

514 citations

Journal ArticleDOI
TL;DR: Common themes of localized signal generation and the spatially localized recruitment of effector proteins appear to underlie mechanisms employed in signal transduction, cytoskeletal, and membrane trafficking events.
Abstract: Signaling roles for phosphoinositides that involve their regulated hydrolysis to generate second messengers have been well characterized. Recent work has revealed additional signaling roles for phosphoinositides that do not involve their hydrolysis. PtdIns 3-P, PtdIns 3,4,5-P3, and PtdIns 4,5-P2 function as site-specific signals on membranes that recruit and/or activate proteins for the assembly of spatially localized functional complexes. A large number of phosphoinositide-binding proteins have been identified as the potential effectors for phosphoinositide signals. Common themes of localized signal generation and the spatially localized recruitment of effector proteins appear to underlie mechanisms employed in signal transduction, cytoskeletal, and membrane trafficking events.

493 citations

Journal ArticleDOI
TL;DR: This paper provides an overview of the biochemistry, biophysics, and neuropathology of α‐synuclein aggregation and possesses remarkable conformational plasticity.
Abstract: Aggregation of α-synuclein, an abundant and conserved pre-synaptic brain protein, is implicated as a critical factor in several neurodegenerative diseases. These diseases, known as synucleinopathies, include Parkinson’s disease, dementia with Lewy bodies (LBs), diffuse LB disease, the LB variant of Alzheimer’s disease, multiple system atrophy, and neurodegeneration with brain iron accumulation type I. Although the precise nature of in vivoα-synuclein function remains elusive, considerable knowledge has been accumulated about its structural properties and conformational behavior. α-Synuclein is a typical natively unfolded protein. It is characterized by the lack of rigid, well-defined, 3-D structure and possesses remarkable conformational plasticity. The structure of this protein depends dramatically on its environment and it accommodates a number of unrelated conformations. This paper provides an overview of the biochemistry, biophysics, and neuropathology of α-synuclein aggregation.

493 citations

Journal ArticleDOI
TL;DR: A hypothesis whereby synuclein supports localized, experience‐dependent turnover of synaptic membranes may be important for lifelong learning and memory functions and may be especially vulnerable to disruption in aging‐associated neurodegenerative diseases is outlined.
Abstract: Synucleins are small highly conserved proteins in vertebrates, especially abundant in neurons and typically enriched at presynaptic terminals. Three genes in humans produce closely related synuclein proteins, all of which share a large amphipathic domain capable of reversible binding to lipid vesicles. Alpha synuclein has been specifically implicated in neurodegenerative disease. Two point mutations are genetically linked to familial Parkinson's disease, and alpha synuclein appears to form the major fibrillary component of Lewy bodies. Alpha synuclein also contributes to the intracellular inclusions of multiple system atrophy, and a fragment has been found in senile plaques in Alzheimer's disease. Although their normal cellular functions are unknown, several observations suggest the synucleins may serve to integrate presynaptic signaling and membrane trafficking. Alpha synuclein has been identified as a potent and selective inhibitor of phospholipase D2, which produces phosphatidic acid (to which synuclein binds) and is believed to function in the partitioning of membranes between the cell surface and intracellular stores. We outline a hypothesis whereby synuclein supports localized, experience-dependent turnover of synaptic membranes. Such a process may be important for lifelong learning and memory functions and may be especially vulnerable to disruption in aging-associated neurodegenerative diseases.

462 citations

Journal ArticleDOI
TL;DR: This review focuses on the lipid precursors and products of mammalian PLD metabolism, especially phosphatidic acid and the roles this lipid performs in the mediation of the functions of PLD.
Abstract: Phospholipase D (PLD) hydrolyzes the phosphodiester bond of the glycerolipid phosphatidylcholine, resulting in the production of phosphatidic acid and free choline. Phosphatidic acid is widely considered to be the intracellular lipid mediator of many of the biological functions attributed to PLD. However, phosphatidic acid is a tightly regulated lipid in cells and can be converted to other potentially bioactive lipids, including diacylglycerol and lysophosphatidic acid. PLD activities have been described in multiple organisms, including plants, mammals, bacteria and yeast. In mammalian systems, PLD activity regulates the actin cytoskeleton, vesicle trafficking for secretion and endocytosis, and receptor signaling. PLD is in turn regulated by phosphatidylinositol-4,5-bisphosphate, protein kinase C and ADP Ribosylation Factor and Rho family GTPases. This review focuses on the lipid precursors and products of mammalian PLD metabolism, especially phosphatidic acid and the roles this lipid performs in the mediation of the functions of PLD.

458 citations

References
More filters
Journal Article
TL;DR: The general protein apparatus used by all eukaryotes for intracellular transport, including secretion and endocytosis, and for triggered exocyTosis of hormones and neurotransmitters, is uncovered.
Abstract: Recent advances have uncovered the general protein apparatus used by all eukaryotes for intracellular transport, including secretion and endocytosis, and for triggered exocytosis of hormones and neurotransmitters. Membranes are shaped into vesicles by cytoplasmic coats which then dissociate upon GTP hydrolysis. Both vesicles and their acceptor membranes carry targeting proteins which interact specifically to initiate docking. A general apparatus then assembles at the docking site and fuses the vesicle with its target.

2,174 citations


"Phospholipase D Stimulates Release ..." refers background in this paper

  • ...The essential role ARF1 plays in vesicle trafficking (Donaldson and Klausner, 1994; Rothman, 1994), its regulation of PLD (Brown et al., 1993; Kahn et al., 1993; Cockcroft et al., 1994; Liscovitch and Cantley, 1995), the presence of an ARF-regulated form of PLD in Golgi membranes (Ktistakis et al.,…...

    [...]

  • ...The essential role ARF1 plays in vesicle trafficking (Donaldson and Klausner, 1994; Rothman, 1994), its regulation of PLD (Brown et al....

    [...]

Journal ArticleDOI
02 Apr 1993-Science
TL;DR: Overexpression of VPS34p resulted in an increase in PI 3-kinase activity, and this activity was specifically precipitated with antisera to Vps34p.
Abstract: The VPS34 gene product (Vps34p) is required for protein sorting to the lysosome-like vacuole of the yeast Saccharomyces cerevisiae. Vps34p shares significant sequence similarity with the catalytic subunit of bovine phosphatidylinositol (PI) 3-kinase [the 110-kilodalton (p110) subunit of PI 3-kinase], which is known to interact with activated cell surface receptor tyrosine kinases. Yeast strains deleted for the VPS34 gene or carrying vps34 point mutations lacked detectable PI 3-kinase activity and exhibited severe defects in vacuolar protein sorting. Overexpression of Vps34p resulted in an increase in PI 3-kinase activity, and this activity was specifically precipitated with antisera to Vps34p. VPS34 encodes a yeast PI 3-kinase, and this enzyme appears to regulate intracellular protein trafficking decisions.

925 citations


"Phospholipase D Stimulates Release ..." refers background in this paper

  • ...Earlier work (Herman et al., 1992; Schu et al., 1993; Stack and Emr, 1994) demonstrated that the yeast VPS34 gene encodes a PtdIns-3-kinase that is essential for protein transport from the Golgi apparatus to the vacuole....

    [...]

Journal ArticleDOI
TL;DR: PC hydrolysis by PLA2, PLC or PLD is a widespread response elicited by most growth factors, cytokines, neurotransmitters, hormones and other extracellular signals and the mechanisms can involve G-proteins, PKC, Ca2+ and tyrosine kinase activities.

924 citations


"Phospholipase D Stimulates Release ..." refers background in this paper

  • ...M ammalian phosphatidylcholine–specific phospholipase D (PLD) 1 has been implicated in a wide range of physiological responses including metabolic regulation, cell proliferation, mitogenesis, oncogenesis, inflammation, secretion, and diabetes (Exton, 1994)....

    [...]

  • ...M ammalian phosphatidylcholine–specific phospholipase D (PLD) 1 has been implicated in a wide range of physiological responses including metabolic regulation, cell proliferation, mitogenesis, oncogenesis, inflammation, secretion, and diabetes (Exton, 1994)....

    [...]

Journal ArticleDOI
17 Dec 1993-Cell
TL;DR: The current finding suggests that PLD activity plays a prominent role in the action of ARF and that ARF may be a key component in the generation of second messengers via phospholipase D.

875 citations


"Phospholipase D Stimulates Release ..." refers background or methods in this paper

  • ...line as substrate in the presence of GTP g S and ARF (Brown et al., 1993),...

    [...]

  • ...Evidence from several laboratories has shown that ARF and PLD co-chromatograph through several purification steps suggesting a direct interaction (Brown et al., 1993; Siddiqi et al., 1995) and ARF and purified PLD do interact in phospholipid micelles (Hammond et al....

    [...]

  • ...The essential role ARF1 plays in vesicle trafficking (Donaldson and Klausner, 1994; Rothman, 1994), its regulation of PLD (Brown et al., 1993; Kahn et al., 1993; Cockcroft et al., 1994; Liscovitch and Cantley, 1995), the presence of an ARF-regulated form of PLD in Golgi membranes (Ktistakis et al....

    [...]

  • ...The eluate was neutralized immediately, dialyzed against incubation buffer, and assayed for PLD activity (Brown et al., 1993)....

    [...]

  • ...The above results, together with the observation that ARF can activate PLD (Brown et al., 1993; Cockcroft et al., 1994; Ktistakis et al., 1995, 1996), suggested that ARF stimulation of nascent vesicle budding might occur via PLD activation....

    [...]

Journal ArticleDOI
15 Mar 1996-Science
TL;DR: Growing evidence suggests that phosphorylation-dephosphorylation of the polar heads of phosphoinositides in specific intracellular locations signals either the recruitment or the activation of proteins essential for vesicular transport.
Abstract: Phosphorylated products of phosphatidylinositol play critical roles in the regulation of membrane traffic, in addition to their classical roles as second messengers in signal transduction at the cell surface. Growing evidence suggests that phosphorylation-dephosphorylation of the polar heads of phosphoinositides (polyphosphorylated inositol lipids) in specific intracellular locations signals either the recruitment or the activation of proteins essential for vesicular transport. Cross talk between phosphatidylinositol metabolites and guanosine triphosphatases is an important feature of these regulatory mechanisms.

724 citations


"Phospholipase D Stimulates Release ..." refers background in this paper

  • ...Evidence from several laboratories has implicated phospholipid-modifying enzymes and inositol phospholipid metabolism in mediating various steps of intracellular vesicular transport (Boman and Kahn, 1995; Liscovitch and Cantley, 1995; De Camilli et al., 1996)....

    [...]

  • ...…coatomer to Golgi membranes (Ktistakis et al., 1995, 1996) and the increasing evidence that phospholipid-modifying enzymes play a role in membrane trafficking (Liscovitch and Cantley, 1995; De Camilli et al., 1996), we hypothesized that PLD could be a link between ARF and secretory vesicle release....

    [...]

Related Papers (5)