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An isoform‐specific PDZ‐binding motif targets type I PIP5 kinase beta to the uropod and controls polarization of neutrophil‐like HL60 cells

2010; Wiley; Volume: 24; Issue: 9 Linguagem: Inglês

10.1096/fj.09-153106

1530-6860

Santos Mañes, Gloria Fuentes, Rosa M. Peregil, Ana M. Rojas, Rosa Ana Lacalle,

Cancer-related gene regulation

Type I phosphatidylinositol 4-phosphate 5-kinase (PIP5KI)-β participates in establishing polarity during leukocyte chemotaxis. Its final 83 amino acids localize PIP5KIβ to the uropod of chemotaxing neutrophils and T cells, and interact with ezrin-radixinmoesin (ERM) proteins and EBP50 (4.1-ERM-binding phosphoprotein 50), a scaffold protein with 2 PDZ (PSD-95, disc large, ZO-1) domains. The structural motifs at the PIP5KIβ C terminus that confer signaling specificity are, nonetheless, unknown. We show that the last 4 residues of PIP5KIβ constitute an atypical PDZ-binding motif, which steers PIP5KIβ to the uropod by binding to both EBP50 PDZ domains. Molecular modeling and mutagenesis indicated that PDZ-binding motif is necessary for PIP5KIβ localization and for chemoattractant-induced neutrophil polarization. Polarity in cells that express PIP5KIβ mutants lacking the PDZ-binding motif was restored by overexpression of PIP5KIβ, but not of PIP5KIγ_i2, another isoform that localizes to the neutrophil uropod. Our results identify an isoform-specific PDZ-binding motif in PIP5KIβ, which confers specificity for PIP5KIβ signaling at the uropod during leukocyte chemotaxis.—Mañes, S., Fuentes, G., Peregil, R. M., Rojas, A. M., Lacalle, R. A. An isoform-specific PDZ-binding motif targets type I PIP5 kinase beta to the uropod and controls polarization of neutrophil-like HL60 cells. FASEB J. 24, 3381–3392 (2010). www.fasebj.org