Implication of acyl chain of diacylglycerols in activation of different isoforms of protein kinase C

ABSTRACT We synthesized diacylglycerols (DAGs) containing ω‐6 or ω‐3 polyunsaturated fatty acids [i.e., 1‐stearoyl‐2‐arachidonoyl‐sn‐glycerol (SAG), 1‐stearoyl‐2‐docosahexaenoyL‐sn‐glycerol (SDG), and 1‐stearoyl‐2‐eicosapentaenoyl‐sn‐glycerol (SEG)] and assessed their efficiency on activation of conventional (α, βI, γ) and novel (ε, δ) protein kinase C (PKC). SAG exerted significantly higher stimulatory effects than SDG and SEG on activation of PKCα and PKCδ. Activation of PKCβI by SEG and SDG was higher than that by SAG. Activation of PKCγ did not differ significantly among DAG molecular species. Addition of SAG to assays containing SEG and SDG exerted additive effects on activation of α and ε, but not on βI and γ, isoforms of PKC. SDG‐ and SEG‐induced activation of PKCδ was significantly curtailed by the addition of SAG. Three DAG species significantly curtailed the PMA‐induced activation of βl, γ, and δ, but not of α and ε, isoforms of PKC. Our study demonstrates for the first time that in vitro activation of different PKC isoenzymes vary in response to different DAG species, and one can envisage that this differential regulation may be responsible for their in vivo effects on target organs.—Madani, S., Hichami, A., Legrand, A., Belleville, J., Khan, N. A. Implication of acyl chain of diacylglycerols in activation of different isoforms of protein kinase C. FASEB J. 15, 2595–2601 (2001)