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

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• 作者：Paul M. Steed ; Steven Nagar ; and Lawrence P. Wennogle
• 刊名：Biochemistry
• 出版年：1996
• 出版时间：April 23, 1996
• 年：1996
• 卷：35
• 期：16
• 页码：5229 - 5237
• 全文大小：426K
• 年卷期：v.35,no.16(April 23, 1996)
• ISSN：1520-4995

文摘

Increases in intracellular phosphatidic acid levels caused byreceptor-mediated activation ofphospholipase D (PLD) have been implicated in many signal transductionpathways leading to cellularactivation. PLD is known to be regulated by several means,including tyrosine kinase activity, increasesin Ca²⁺, receptor-coupled G proteins, small GTP bindingproteins, ceramide metabolism, and proteinkinase C. We have investigated an additional regulatory effect onPLD activity involving nucleosidetriphosphates (NTPs). A NTP binding protein copurifies with PLDactivity from rabbit brains using aGTP-agarose affinity column, and this protein stimulates PLD activityonly in the absence of NTPs.The NTP effect is reversible and labile, and the binding proteinis separable from the PLD activity byheparin-agarose chromatography. We identified this protein asthe actin-binding protein gelsolin byamino acid sequencing following peptide mapping. This finding wasverified by the co-immunoprecipitationof gelsolin and PLD activity as well as by the reconstitution ofgelsolin-dependent nucleotide sensitivePLD activity by the addition of purified gelsolin to gelsolin-free PLD.Our data indicate that actinrearrangements and PLD signaling are coordinately regulated through thephysical association betweenPLD and gelsolin and that this interaction may also serve to amplifyboth PLD signaling and actinreorganization.