Ligand-independent pathway that controls stability of interferon alpha receptor.

Jianghuai Liu (1) , Alexander Plotnikov (1) , Anamika Banerjee (1) , K. G. Suresh Kumar (1) , Josiane Ragimbeau (2) , Zrinka Marijanovic (2) , Darren P. Baker (3) , Sandra Pellegrini (2) , Serge Y. Fuchs (1)

1 School of Veterinary Medicine
2 Signalisation des Cytokines - Cytokine Signaling
3 Biogen Idec Inc.

Ligand-specific negative regulation of cytokine-induced signaling relies on down regulation of the cytokine receptors. Down regulation of the IFNAR1 sub-unit of the Type I interferon (IFN) receptor proceeds via lysosomal receptor proteolysis, which is triggered by ubiquitination that depends on IFNAR1 serine phosphorylation. While IFN-inducible phosphorylation, ubiquitination, and degradation requires the catalytic activity of the Tyk2 Janus kinase, here we found the ligand- and Tyk2-independent pathway that promotes IFNAR1 phosphorylation, ubiquitination, and degradation when IFNAR1 is expressed at high levels. A major cellular kinase activity that is responsible for IFNAR1 phosphorylation in vitro does not depend on either ligand or Tyk2 activity. Inhibition of ligand-independent IFNAR1 degradation suppresses cell proliferation. We discuss the signaling events that might lead to ubiquitination and degradation of IFNAR1 via ligand-dependent and independent pathways and their potential physiologic significance.

Domaines: Immunologie

Jianghuai Liu, Alexander Plotnikov, Anamika Banerjee, K. G. Suresh Kumar, Josiane Ragimbeau, et al.. Ligand-independent pathway that controls stability of interferon alpha receptor.. Biochemical and Biophysical Research Communications, 2008, 367 (2), pp.388-93. ⟨10.1016/j.bbrc.2007.12.137⟩. ⟨pasteur-00332724⟩