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A functional bipartite nuclear localisation signal in the cytokine interleukin‐5
Author(s) -
Jans David A.,
Briggs Lyndall J.,
Gustin Sonja E.,
Jans Patricia,
Ford Sally,
Young Ian G.
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(97)00293-7
Subject(s) - bipartite graph , cytokine , chemistry , signal (programming language) , microbiology and biotechnology , computational biology , physics , biology , computer science , immunology , theoretical computer science , graph , programming language
Interleukin (IL)‐5 is central in regulating eosinophilia in allergic disease and parasitic infections. We have identified a bipartite nuclear localisation signal (NLS) within amino acids 95–111 of human IL‐5 (hIL‐5), also present in mouse IL‐5 (mIL‐5). hIL‐5 and mIL‐5 were labelled fluorescently, and nuclear uptake subsequent to membrane binding and internalisation by intact receptor expressing cells visualised and quantified using confocal laser scanning microscopy. hIL‐5 and mIL‐5 were shown to be transported to the nucleus in in vivo and in vitro nuclear protein import assays. The hIL‐5 NLS was able to target a heterologous protein to the nucleus both in vivo and in vitro. Mutations within the proximal arm of the NLS abrogated nuclear targeting activity, confirming its bipartite nature. The results imply a nuclear signalling role for IL‐5 additional to pathways linked to the membrane receptor system.