Phospholipase D Regulation by a Physical Interaction with the Actin-Binding Protein Gelsolin

Steed, Paul M.; Nagar, Steven; Wennogle, Lawrence P.

doi:10.1021/bi952370j

Cited by 64 publications

(36 citation statements)

References 61 publications

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“…When phagosomes were preincubated with G1-3 and then reisolated on gradients, their subsequent ability to polymerize actin was significantly enhanced (Defacque et al, 2000a). It is possible that gelsolin can bind to and influence the activity of signaling molecules, such as phospholipases C and D (Steed et al, 1996;Baldassare et al, 1997;Sun et al, 1997), that regulate the actin assembly process; pharmacological evidence suggests that these enzymes are also present and active on isolated phagosomes (our unpublished data). However, preincubation or coincubation of LBPs with gelsolin G1-3 had no effects on the synthesis of PI(4)P, P(4,5)P 2 , or phosphatidic acid by phagosomes (results not shown).…”

Section: Discussionmentioning

confidence: 82%

Phosphoinositides Regulate Membrane-dependent Actin Assembly by Latex Bead Phagosomes

Defacque

Bos

Garvalov

et al. 2002

MBoC

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Actin assembly on membrane surfaces is an elusive process in which several phosphoinositides (PIPs) have been implicated. We have reconstituted actin assembly using a defined membrane surface, the latex bead phagosome (LBP), and shown that the PI(4,5)P 2 -binding proteins ezrin and/or moesin were essential for this process (Defacque et al., 2000b). Here, we provide several lines of evidence that both preexisting and newly synthesized PI(4,5)P 2 , and probably PI(4)P, are essential for phagosomal actin assembly; only these PIPs were routinely synthesized from ATP during in vitro actin assembly. Treatment of LBP with phospholipase C or with adenosine, an inhibitor of type II PI 4-kinase, as well as preincubation with anti-PI(4)P or anti-PI(4,5)P 2 antibodies all inhibited this process. Incorporation of extra PI(4)P or PI(4,5)P 2 into the LBP membrane led to a fivefold increase in the number of phagosomes that assemble actin. An ezrin mutant mutated in the PI(4,5)P 2 -binding sites was less efficient in binding to LBPs and in reconstituting actin assembly than wild-type ezrin. Our data show that PI 4-and PI 5-kinase, and under some conditions also PI 3-kinase, activities are present on LBPs and can be activated by ATP, even in the absence of GTP or cytosolic components. However, PI 3-kinase activity is not required for actin assembly, because the process was not affected by PI 3-kinase inhibitors. We suggest that the ezrin-dependent actin assembly on the LBP membrane may require active turnover of D4 and D5 PIPs on the organelle membrane. INTRODUCTIONA significant fraction of the de novo nucleation of actin in cells occurs on the cytoplasmic surface of eukaryotic cell membranes, especially the plasma membrane (Tilney, 1976;Carraway and Carraway, 1989;Small et al., 1995;Mitchison and Cramer, 1996), and a role for phosphoinositides in this elusive process has been widely discussed (Divecha and Irvine, 1995;Martin, 1998;Caroni, 2001). However, the precise function of these lipids is still not clear and is likely to be quite complicated. In several cellular systems that show rapid actin assembly in response to extracellular ligands, synthesis of phosphoinositides, especially phosphatidylinositol-4,5-bisphosphate [PI(4,5)P 2 ], and in some cases phosphatidylinositol-3,4,5-trisphosphate [PI(3,4,5)P 3 ], coincides precisely with the transient burst of actin assembly (Eberle et al., 1990;Dobos et al., 1992;Apgar, 1995;Hartwig et al., 1995;Gachet et al., 1997). In addition, overexpression of phosphatidylinositol-4-phosphate [PI(4)P] 5-kinase in cells leads to a significant polymerization of actin (Shibasaki et al., 1997). However, in other systems, the synthesis of PI(4,5)P 2 as well as PI(3,4,5)P 3 coincides more with actin depolymerization, after a transient assembly of F-actin (Apgar, 1995;Gratacap et al., 1998).One important clue to the functions of phosphoinositides in actin assembly/disassembly is that these lipids can bind in vitro to an increasing number of actin-binding proteins (ABPs). Interestingly, two different...

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Section: Discussionmentioning

confidence: 82%

Phosphoinositides Regulate Membrane-dependent Actin Assembly by Latex Bead Phagosomes

Defacque

Bos

Garvalov

et al. 2002

MBoC

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“…Many negative regulators of PLD activity have been identified, including fodrin (16), ␣-actinin (17), actin (19), gelsolin (18), amphiphysin (21), aldolase (20), ␣-/␤-synuclein (24), synaptojanin (22), clathrin assembly protein 3 (23), and collapsin response mediator protein-2 (25). However, the roles of these inhibitors in signal-dependent PLD activity has not been demonstrated.…”

Section: Figmentioning

confidence: 99%

Inhibition of Muscarinic Receptor-linked Phospholipase D Activation by Association with Tubulin

Chae

Lee

et al. 2005

Journal of Biological Chemistry

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Mammalian phospholipase D (PLD) is considered a key enzyme in the transmission signals from various receptors including muscarinic receptors. PLD activation is a rapid and transient process, but a negative regulator has not been found that inhibits signal-dependent PLD activation. Here, for the first time, we report that tubulin binding to PLD 2 is an inhibition mechanism for muscarinic receptor-linked PLD 2 activation. Tubulin was identified in an immunoprecipitated PLD 2 complex from COS-7 cells by peptide mass fingerprinting. The direct interaction between PLD 2 and tubulin was found to be mediated by a specific region of PLD 2 (amino acids 476 -612). PLD 2 was potently inhibited (IC 50 <10 nM) by tubulin binding in vitro. In cells, the interaction between PLD 2 and tubulin was increased by the microtubule disrupting agent nocodazole and reduced by the microtubule stabilizing agent Taxol. Moreover, PLD 2 activity was found to be inversely correlated with the level of monomeric tubulin. In addition, we found that interaction with and the inhibition of PLD 2 by monomeric tubulin is important for the muscarinic receptor-linked PLD signaling pathway. Interaction between PLD 2 and tubulin was increased only after 1-2 min of carbachol stimulation when carbachol-stimulated PLD 2 activity was decreased. The expression of the tubulin binding region of PLD 2 blocked the later decrease in carbachol-induced PLD activity by masking tubulin binding. Taken together, these results indicate that an increase in local membrane monomeric tubulin concentration inhibits PLD 2 activity, and provides a novel mechanism for the inhibition of muscarinic receptor-induced PLD 2 activation by interaction with tubulin. Mammalian phospholipase D (PLD)1 hydrolyzes membrane phosphatidylcholine to generate phosphatidic acid and choline. PLD activity is dramatically activated in response to a variety of signals, including hormones, neurotransmitters, and growth factors (1). PLD products, phosphatidic acid itself or the hydrolyzed product diacylglycerol, have been known to act as intracellular lipid second messengers and to be involved in multiple physiological events, such as, the promotion of mitogenesis, stimulation of respiratory bursts, secretory processes, and actin cytoskeletal reorganization (2-7). Therefore, signal-dependent PLD activity must be tightly controlled in cells.Many reports have been issued about the mechanisms of receptor-mediated PLD activation. Although the mammalian PLD isozymes, PLD 1 and PLD 2 , have some different regulatory properties, in general, agonist-induced PLD is activated by various protein kinases, including protein kinase C, proteintyrosine kinase, and the MAP kinase family, in addition to small G proteins of the ARF, Rho, and Ras families (8 -13). The signal-dependent activation of PLD is rapid and transient. Although, the activation kinetics depend on the stimulus and cell type, the PLD signal is usually diminished within 10 min (14). However, the mechanisms involved in PLD signal inhibition remain unknow...

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“…By analogy, several actin-binding proteins, such as profilin, gelsolin, and CapG, have already been shown to bind PIP 2 and to modulate the activity of regulatory PLC isozymes both in vitro (Goldschmidt-Clermont et al, 1990Banno et al, 1992;Steed et al, 1996;Sun et al, 1997) and in vivo (Sun et al, 1997). The binding of PIP 2 by the above-mentioned proteins appears to prevent phospholipase access to this substrate (GoldschmidtClermont et al, 1990(GoldschmidtClermont et al, , 1991Banno et al, 1992;Steed et al, 1996;Sun et al, 1997). Because high tubulin concentrations inhibit PLC␤ 1 in vitro, a similar inhibitory mechanism was suggested (Popova et al, 1997).…”

Section: Kinase Cmentioning

confidence: 99%

Phosphatidylinositol 4,5-Bisphosphate Modifies Tubulin Participation in Phospholipase Cβ₁Signaling

Popova¹,

Greene²,

Wang³

et al. 2002

J. Neurosci.

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Phospholipase D Regulation by a Physical Interaction with the Actin-Binding Protein Gelsolin

Cited by 64 publications

References 61 publications

Phosphoinositides Regulate Membrane-dependent Actin Assembly by Latex Bead Phagosomes

Phosphoinositides Regulate Membrane-dependent Actin Assembly by Latex Bead Phagosomes

Inhibition of Muscarinic Receptor-linked Phospholipase D Activation by Association with Tubulin

Phosphatidylinositol 4,5-Bisphosphate Modifies Tubulin Participation in Phospholipase Cβ₁Signaling

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Phospholipase D Regulation by a Physical Interaction with the Actin-Binding Protein Gelsolin

Cited by 64 publications

References 61 publications

Phosphoinositides Regulate Membrane-dependent Actin Assembly by Latex Bead Phagosomes

Phosphoinositides Regulate Membrane-dependent Actin Assembly by Latex Bead Phagosomes

Inhibition of Muscarinic Receptor-linked Phospholipase D Activation by Association with Tubulin

Phosphatidylinositol 4,5-Bisphosphate Modifies Tubulin Participation in Phospholipase Cβ1Signaling

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Phosphatidylinositol 4,5-Bisphosphate Modifies Tubulin Participation in Phospholipase Cβ₁Signaling