These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Anti-IgM-mediated growth inhibition of a human B lymphoma cell line is independent of phosphatidylinositol turnover and protein kinase C activation and involves tyrosine phosphorylation.
    Author: Beckwith M, Urba WJ, Ferris DK, Freter CE, Kuhns DB, Moratz CM, Longo DL.
    Journal: J Immunol; 1991 Oct 01; 147(7):2411-8. PubMed ID: 1918971.
    Abstract:
    The RL cell line is an EBV-negative, surface IgM, IgD-positive B lymphoma line, which is significantly growth arrested in the presence of acrylamide-linked antibodies to the surface IgM receptor. We demonstrate here that activation of protein kinase C (PKC) with PMA abrogates anti-IgM-induced phosphoinositide turnover and Ca2+ mobilization; however, growth inhibition is not affected. In addition, inhibitors of PKC are unable to reverse the anti-IgM-mediated growth inhibition. Two-dimensional gel electrophoresis reveals a different pattern of protein phosphorylation after treatment of RL with PMA or anti-IgM. These data strongly suggest that anti-IgM-induced growth inhibition does not rely on phospholipase C-mediated phosphoinositide turnover, Ca2+ mobilization, or PKC activation. On the other hand, the phosphatase inhibitor orthovanadate results in an augmentation of proteins phosphorylated on tyrosine and the growth inhibition which follows anti-IgM treatment. Furthermore, protein tyrosine kinase inhibitors, genistein and herbimycin A, are able to reverse the anti-IgM-induced inhibition of growth. These data demonstrate that multiple signaling pathways are activated by the interaction of anti-IgM with its ligand, and suggest that tyrosine kinase activation is a critical component of the inhibitory response.
    [Abstract] [Full Text] [Related] [New Search]