Mechanism of inhibition of protein kinase C by 14-3-3 isoforms. 14-3-3 isoforms do not have phospholipase A2 activity.
The ability of individual members of the 14-3-3 protein family to inhibit protein kinase C (PKC) has been studied by using a synthetic peptide based on the specific 80 kDa substrate for PKC (MARCKS protein) in two different assay systems. Recombinant 14-3-3 and isoforms renatured by a novel method after separation by reverse-phase h.p.l.c. were studied. The detailed effects of diacylglycerol and the phorbol ester phorbol 12-myristate 13-acetate on the inhibition were also investigated. This suggests that one of the sites of interaction of 14-3-3 may be the cysteine-rich (C1) domain in PKC. Since a region in secreted phospholipase A2 (PLA2) shares similarity with this domain, the ability of 14-3-3 to interact with mammalian PLA2 was studied. Cytosolic PLA2 has some similarity to the C2 region of PKC, and the effect of 14-3-3 on this class of PLA2 was also analysed. In contrast with a previous report, no PLA2 activity was found in brain 14-3-3, nor in any of the recombinant proteins tested. These include zeta 14-3-3 isoform, on which the original observation was made.
Robinson
K
K
Laboratory of Protein Structure, National Institute for Medical Research, Mill Hill, London, U.K.
Jones
D
D
Patel
Y
Y
Martin
H
H
Madrazo
J
J
Martin
S
S
Howell
S
S
Elmore
M
M
Finnen
M J
MJ
Aitken
A
A
D048948:14-3-3 Proteins; D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000378:metabolism / Q000494:pharmacology*; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D010743:Phospholipids / Q000378:metabolism; D011493:Protein Kinase C / Q000037:antagonists & inhibitors*; D017386:Sequence Homology, Amino Acid; D012756:Sheep; D013379:Substrate Specificity; D014446:Tyrosine 3-Monooxygenase
D048948:14-3-3 Proteins; D009419:Nerve Tissue Proteins; D010743:Phospholipids; D014446:Tyrosine 3-Monooxygenase; D011493:Protein Kinase C; D010741:Phospholipases A; D054467:Phospholipases A2; D002118:Calcium