5-Lipoxygenase Compartmentalization in Granulocytic Cells Is Modulated by an Internal Bipartite Nuclear Localizing Sequence and Nuclear Factor κB Complex Formation

Abstract

A region of basic amino acids spanning residues 639–656 in the human 5-lipoxygenase sequence resembles a consensus bipartite nuclear localizing sequence. A synthetic peptide consisting of the Kaposi fibroblast growth factor signal sequence fused to the 5-lipoxygenase639–656bipartite nuclear localizing sequence has a prominent inhibitory effect on 5-lipoxygenase catalysis in granulocytic HL-60 cells activated by calcium ionophor A23187. Recombinant 5-lipoxygenase was not affected by the peptide. The peptide also inhibited redistribution of 5-lipoxygenase from the cytosol to the nuclear membrane of HL-60 cells stimulated by A23187. 5-Lipoxygenase protein was detected in nuclear factor κB (NF-κB) p65 subunit immunoprecipitate fractions prepared from HL-60 cell lysates. The amount of 5-lipoxygenase protein coimmunoprecipitated by NF-κB antiserum was increased following A23187 stimulation. In cells treated with agents that block 5-lipoxygenase translocation to the nucleus, 5-lipoxygenase protein appearing in the NF-κB immunoprecipitate was diminished. Our results implicate an internal bipartite nuclear localizing sequence as a regulatory domain that modulates 5-lipoxygenase redistribution and catalysis in granulocytic cells. Additionally, our results suggest that molecular determinants which govern 5-lipoxygenase and NF-κB redistribution to the nucleus may be coordinately controlled in granulocytic cells.