Stable localization of signaling complex is essential for robust morphogenesis of polarized cells.Cell elongation involves molecular signaling centers which coordinately regulate intracellular transport and cytoskeletal structures.In Drosophila bristle elongation, the protein kinase IKKe is activated at the distal tip of the growing bristle, and regulates the shuttling movement of recycling endosomes and cytoskeletal organization.However, how the distal-tip localization of IKKe is established and maintained during bristle elongation is unknown.Here we demonstrate that IKKes distal tip location is regulated by Spindle-F (Spn-F), which is stably retained to the distal tip and functions as an adaptor linking IKKe to cytoplasmic dynein.We found that Javelin-like (Jvl) is a key regulator of Spn-Fs retention.In jvl mutant bristles,IKKe and Spn-F initially localize to the distal tip, but fail to be retained there.In S2 cells, particles that stain positive for Jvl or Spn-F move in a microtubule-dependent manner, whereas Jvl/Spn-F double-positive particles are immobile, indicating that Jvl and Spn-F are transported separately, and upon forming a complex, immobilize each other.These results suggest that polarized transport and selective retention regulate the distal tip localization of the IKKe/Spn-F complex during bristle-cell elongation.