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Role of phospholipase C and D signalling pathways in vasopressin‐dependent myogenic differentiation
Author(s) -
Naro Fabio,
Donchenko Viktoria,
Minotti Simona,
Zolla Lello,
Molinaro Mario,
Adamo Sergio
Publication year - 1997
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/(sici)1097-4652(199704)171:1<34::aid-jcp5>3.0.co;2-i
Subject(s) - phosphatidic acid , phospholipase c , dephosphorylation , vasopressin , phospholipase d , phosphatidylethanol , microbiology and biotechnology , medicine , endocrinology , diacylglycerol kinase , biology , myogenesis , myocyte , phosphatidylinositol , signal transduction , protein kinase c , chemistry , phosphatase , biochemistry , phosphorylation , phospholipid , membrane
Arg 8 ‐vasopressin (AVP) is a potent inducer of myogenic differentiation stimulating the expression of myogenic regulatory factors. To understand the mechanism of its effect on myogenesis, we investigated the early signals induced by AVP in myogenic target cells. In the rat skeletal muscle cell line L6, AVP selectively stimulates phosphatidylinositol (PtdIns) and phosphatidylcholine (PtdCho) breakdown, through the activation of phospholipases C and D (PLC, PLD), as shown by the generation of Ins(1,4,5)P 3 and phosphatidylethanol (PtdEtOH), respectively. AVP induces the biphasic increase of sn‐1,2‐diacylglycerol (DAG) consisting in a rapid peak followed by a sustained phase, and the monophasic generation of phosphatidic acid (PA). Propranolol (a PA phosphatase inhibitor) and Zn 2+ (a PLD inhibitor), abolish the sustained phase of DAG generation. Our data indicate that PtdIns‐PLC activity is mainly responsible for the rapid phase of AVP‐dependent DAG generation, whereas the sustained phase is dependent upon PtdCho‐PLD activity and PA dephosphorylation, ruling out any significant role of DAG kinase. Modifications of PA level correlate with parallel changes of PLC activity, indicating a possible cross‐talk between the two signal transduction pathways in the intact cell. PLD activation is elicited at AVP concentrations two orders of magnitude lower than those required for PLC activation. The differentiation of L6 myoblasts into multinucleated fibers is stimulated significantly by AVP at concentrations at which PLD, but not PLC, is activated. These data provide the first evidence for an important role of PLD in the mechanism of AVP‐induced muscle differentiation. J. Cell. Physiol. 171:34–42, 1997. © 1997 Wiley‐Liss, Inc.