Ro 31-8220 (Synonyms: Bisindolylmaleimide IX)

Ro 31-8220 is a selective inhibitor of protein kinase C (PKC) with IC50 values of 5, 24, 14, 27, and 24 nM for PKC α, PKC βI, PKC βII, PKC γ and PKC ε, respectively [1].

PKC is a monomeric Ca2+- and phospholipid-dependent Ser/Thr protein kinases and plays an important role in growth factor-activated signaling and malignant transformation.

Ro 31-8220 is a selective inhibitor of PKC. Also, Ro 31-8220 increased growth factor-stimulated expression of c-Jun but inhibited MKP-1 and c-Fos expression. Ro-31-8220 strongly stimulated the stress-activated protein kinase JNK1 in a PKC-independent way [2]. In peripheral blood mononuclear cells, Ro 31-8220 inhibited the production of mitogen-induced interleukin (IL) -2 and IL-2-dependent T lymphoblast proliferation with IC50 values of 80 and 350 nM, respectively. Also, Ro 31-8220 (400 nM) inhibited IL-2Rα (CD25) expression by 27%, which suggested that Ro 31-8220 inhibited early and late T cell activation [3].

In rat adipocytes and L6 myotubes, RO 31-8220 activated c-Jun N-terminal kinase (JNK) and glycogen synthase (GS) and stimulated glucose incorporation into glycogen. While, RO 31-8220 inhibited the activity of extracellular response kinases 1 and 2 (ERK1/2) in a PKC-independent way [4].

References:
[1].  Wilkinson SE, Parker PJ, Nixon JS. Isoenzyme specificity of bisindolylmaleimides, selective inhibitors of protein kinase C. Biochem J, 1993, 294 ( Pt 2): 335-337.
[2].  Beltman J, McCormick F, Cook SJ. The selective protein kinase C inhibitor, Ro-31-8220, inhibits mitogen-activated protein kinase phosphatase-1 (MKP-1) expression, induces c-Jun expression, and activates Jun N-terminal kinase. J Biol Chem, 1996, 271(43): 27018-27024.
[3].  Geiselhart L, Conti DJ, Freed BM. RO 31-8220, a novel protein kinase C inhibitor, inhibits early and late T cell activation events. Transplantation, 1996, 61(11): 1637-1642.
[4].  Standaert ML, Bandyopadhyay G, Antwi EK, et al. RO 31-8220 activates c-Jun N-terminal kinase and glycogen synthase in rat adipocytes and L6 myotubes. Comparison to actions of insulin.