Molecular mechanisms of PKCα localization and activation by arachidonic acid.: The C2 domain also plays a role

被引:32
作者
López-Nicolás, R [1 ]
López-Andreo, MJ [1 ]
Marín-Vicente, C [1 ]
Gómez-Fernández, JC [1 ]
Corbalán-García, S [1 ]
机构
[1] Univ Murcia, Dept Bioquim & Biol Mol A, Fac Vet, E-30100 Murcia, Spain
关键词
C2; domain; C1; calcium; arachidonic acid; PKC;
D O I
10.1016/j.jmb.2006.01.018
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Arachidonic acid, one of the major unsaturated fatty acids released during cell stimulation, participates in the signaling necessary for activation of different enzymes, including protein kinase C (PKC). Here, we demonstrate that arachidonic acid is a direct activator of PKC alpha, but needs the cooperation of Ca2+ to exert its function. By using several mutants of the C2 and C I domains, we were able to determine the molecular mechanism of this activation. More specifically, site-directed mutagenesis in key residues found in the C2 domain showed that the Ca2+-binding region was essential for the arachidonic acid-dependent localization and activation of PKC alpha. However, the lysine-rich cluster, also located in the C2 domain, played no relevant role in either the membrane localization or activation of the enzyme. Moreover, site-directed mutagenesis in key residues placed in the C1A and C1B subdomains, which are responsible for the diacylglycerol/phorbil ester interaction, demonstrated that the C1A subdomain was involved in the membrane localization and activation mechanism. Taken together, these data suggest a very precise mechanism for PKC alpha activation by arachidonic acid, involving a sequential model of activation in which an increase in intracytosolic Ca2+ leads to the interaction of arachidonic acid with the Ca2+-binding region; only after this step, does the C1A subdomain interact with arachidonic acid, leading to full activation of the enzyme. (c) 2006 Elsevier Ltd. All rights reserved.
引用
收藏
页码:1105 / 1120
页数:16
相关论文
共 51 条
[1]   Activation mechanisms of conventional protein kinase C isoforms are determined by the ligand affinity and conformational flexibility of their C1 domains [J].
Ananthanarayanan, B ;
Stahelin, RV ;
Digman, MA ;
Cho, WH .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2003, 278 (47) :46886-46894
[2]   Cellular regulation and proposed biological functions of group VIA calcium-independent phospholipase A2 in activated cells [J].
Balsinde, J ;
Balboa, MA .
CELLULAR SIGNALLING, 2005, 17 (09) :1052-1062
[3]   Roles of ionic residues of the C1 domain in protein kinase C-α activation and the origin of phosphatidylserine specificity [J].
Bittova, L ;
Stahelin, RV ;
Cho, W .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2001, 276 (06) :4218-4226
[4]  
Bögi K, 1998, CANCER RES, V58, P1423
[5]   Role of the Ca2+/phosphatidylserine binding region of the C2 domain in the translocation of protein kinase Cα to the plasma membrane [J].
Bolsover, SR ;
Gomez-Fernandez, JC ;
Corbalan-Garcia, S .
JOURNAL OF BIOLOGICAL CHEMISTRY, 2003, 278 (12) :10282-10290
[6]   A non-capacitative pathway activated by arachidonic acid is the major Ca2+ entry mechanism in rat A7r5 smooth muscle cells stimulated with low concentrations of vasopressin [J].
Broad, LM ;
Cannon, TR ;
Taylor, CW .
JOURNAL OF PHYSIOLOGY-LONDON, 1999, 517 (01) :121-134
[7]  
Cave WT, 1996, NUTRITION, V12, pS39
[8]   Phospholipase A2 isoforms:: a perspective [J].
Chakraborti, S .
CELLULAR SIGNALLING, 2003, 15 (07) :637-665
[9]   Membrane-protein interactions in cell signaling and membrane trafficking [J].
Cho, WH ;
Stahelin, RV .
ANNUAL REVIEW OF BIOPHYSICS AND BIOMOLECULAR STRUCTURE, 2005, 34 :119-151
[10]   The C2 domain of protein kinase Cα is directly involved in the diacylglycerol-dependent binding of the C1 domain to the membrane [J].
Conesa-Zamora, P ;
Gómez-Fernández, JC ;
Corbalán-García, S .
BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR AND CELL BIOLOGY OF LIPIDS, 2000, 1487 (2-3) :246-254