Polymyxin B causes coordinate inhibition of phorbol ester-induced C-kinase activity and proliferation of B lymphocytes.


Journal Article

Lymphocytes were found to be rich in phospholipid/Ca2+-dependent (C-kinase) activity. Addition of polymyxin B (PMB) to in vitro assays of endogenous and exogenous phosphorylation resulted in profound inhibition of C-kinase activity. The phorbol ester 12-o-tetradecanoyl phorbol-13-acetate (TPA) directly activated C-kinase, leading to increased phosphorylation of the same substrates. TPA also stimulated proliferation of B cells as assessed by 3H-thymidine uptake, and PMB strongly inhibited this effect. This coordinate inhibition of TPA-induced phosphorylation and mitogenesis indicates that PMB is a potentially useful inhibitor of C-kinase activity, and that this enzyme may play an important role in mediating B cell responses.

Full Text

Cited Authors

  • Nel, AE; Wooten, MW; Goldschmidt-Clermont, PJ; Miller, PJ; Stevenson, HC; Galbraith, RM

Published Date

  • May 1, 1985

Published In

Volume / Issue

  • 128 / 3

Start / End Page

  • 1364 - 1372

PubMed ID

  • 2988537

Pubmed Central ID

  • 2988537

Electronic International Standard Serial Number (EISSN)

  • 1090-2104

International Standard Serial Number (ISSN)

  • 0006-291X

Digital Object Identifier (DOI)

  • 10.1016/0006-291x(85)91091-5


  • eng