Tài liệu Báo cáo khoa học: Peroxiredoxin II functions as a signal terminator for H2O2-activated

Peroxiredoxin II functions as a signal terminator

for H2O2-activated phospholipase D1

Nianzhou Xiao, Guangwei Du and Michael A. Frohman

Department of Pharmacology and the Center for Developmental Genetics, University Medical Center at Stony Brook, NY, USA

Mammalian phospholipase D (PLD) is a signal-trans￾ducing enzyme that hydrolyzes PtdCho to generate the

membrane-bound lipid signal phosphatidic acid (PA)

(reviewed in [1,2]). PA is a second messenger and can

be further converted into diacylglycerol. PLD is indi￾rectly activated in response to cellular stimulation by

various extracellular agonists including hormones,

growth factors, neurotransmitters, adhesion molecules,

cytokines and physical stimuli. The direct mechanism

by which PLD is activated involves physical interac￾tion with protein kinase C (PKC) and the ADP-ribosy￾lation factor (ARF) and RhoA small GTPase families.

A well-studied role for PLD in stimulation of

NADPH during respiratory oxidative burst has been

described by may groups [3–6] (reviewed in [7]). PLD

functions both directly, by generating PA, which binds

to and stimulates the p47(phox) component of the

NADPH oxidase complex [5,8], and by conversion

of some of the PA into diacylglycerol. Diacylglycerol

recruits PKC to the plasma membrane, which is also

required for NADPH activation [9,10]. Once NADPH

oxidase is activated, it generates H2O2, which can func￾tion to kill intracellular bacteria and play pro-apopto￾tic or anti-apoptotic roles depending on the cellular

context. In addition, H2O2 stimulates PLD activity by

a poorly understood, probably indirect, mechanism

involving tyrosine kinases and PKC [11–13]. This cre￾ates a runaway positive feedback cycle: PLD activation

promotes H2O2 production and PKC recruitment,

which leads to even more PLD activity. This paper

reports the identification of a cellular mechanism by

which this positive feedback cycle may be regulated

and terminated.

In addition to the extensively documented interac￾tions between PLD1 and the proteins (PKC, ARF and

RhoA) that stimulate it directly [14–18], interactions

involving other proteins, such as actin, protein kinase N,

casein-kinase-2-like serine kinase and amphiphysin,

Keywords

hydrogen peroxide; peroxiredoxin II;

phosphatidic acid; phospholipase D1; PMA

Correspondence

M. Frohman, Center for Developmental

Genetics, 438 CMM, Stony Brook, NY

11794-5140, USA

Fax: +1 631 632 1692

Tel: +1 631 632 1476

E-mail: [email protected]

(Received 4 May 2005, revised 3 June

2005, accepted 8 June 2005)

doi:10.1111/j.1742-4658.2005.04809.x

Phospholipase D1 (PLD1) is a signal-transduction regulated enzyme which

regulates several cell intrinsic processes including activation of NAPDH

oxidase, which elevates intracellular H2O2. Several proteins have been

reported to interact with PLD1 in resting cells. We sought to identify pro￾teins that interact with PLD1 after phorbol 12-myristate 13-acetate (PMA)

stimulation. A novel interaction with peroxiredoxin II (PrxII), an enzyme

that eliminates cellular H2O2, which is a known stimulator of PLD1, was

identified by PLD1-affinity pull-down and MS. PMA stimulation was con￾firmed to promote physical interaction between PLD1 and PrxII and to

cause PLD1 and PrxII to colocalize subcellularly. Functional significance

of the interaction was suggested by the observation that over-expression of

PrxII specifically reduces the response of PLD1 to stimulation by H2O2.

These results indicate that PrxII may have a signal-terminating role for

PLD1 by being recruited to sites containing activated PLD1 after cellular

stimulation involving production of H2O2.

Abbreviations

HA, hemagglutinin; MobA, molybdopterin guanine dinucleotide biosynthesis protein AI; PA, phosphatidic acid; PLD, phospholipase D; PKC,

protein kinase C; PMA, phorbol-12-myristate 13-acetate; PrxII, peroxiredoxin II.

FEBS Journal 272 (2005) 3929–3937 ª 2005 FEBS 3929