The cytokine interleukin‐5 (IL‐5) effects cotransport of its receptor subunits to the nucleus in vitro

FEBS Letters

Ford, Sally¹  Gustin, Sonja E¹  Jans, Patricia²  Young, Ian G¹  Briggs, Lyndall J²  Jans, David A² 

[1] Medical Molecular Biology Group, Division of Biochemistry and Molecular Biology, John Curtin School of Medical Research, Australian National University, Canberra, Australia;Nuclear Signalling Laboratory, Division of Biochemistry and Molecular Biology, John Curtin School of Medical Research, Australian National University, P.O. Box 334, Canberra, A.C.T. 2601, Australia

关键词: Interleukin-5;    Nuclear protein import;    Confocal laser scanning microscopy;    Piggy back transport;    Cytokine receptor;   

DOI  :  10.1016/S0014-5793(97)00622-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Interleukin (IL)-5 is central in regulating eosinophilia in allergic disease and parasitic infections. We have recently shown that human (h) IL-5 both possesses a functional nuclear localization signal capable of targeting a heterologous protein to the nucleus and localises to the nucleus of intact receptor-expressing cells. In this study, the extracellular domains of the hIL-5 α- and β-receptor subunits were expressed in baculovirus, fluorescently labelled and assayed for nuclear targeting in vitro in the absence and presence of IL-5. The β-subunit, which lacks IL-5 binding activity, only accumulated in the nucleus in the presence of both the hIL-5 binding α-subunit and hIL-5. The IL-5-binding α-subunit showed similar results. IL-5 thus effected nuclear transport of its α- and β-receptor subunits apparently through a ‘piggy back’ mechanism, raising the possibility that IL-5's nuclear signalling role may be to cotarget its receptor subunits to the nucleus. This is the first demonstration of nuclear protein piggy back transport in vitro.

【 授权许可】

Unknown