# NEK7 phosphorylation of cortactin modulates the migratory capacity of cells expressing EML4-ALK V3

## TL;DR

This study shows how EML4-ALK V3 promotes cancer cell migration by altering the actin cytoskeleton through NEK7-mediated phosphorylation of cortactin.

## Contribution

The study identifies cortactin as a novel downstream substrate of NEK7 in EML4-ALK V3-driven cell migration.

## Key findings

- Cortactin phosphorylation by NEK7 in the ABR is essential for EML4-ALK V3-induced cell migration.
- Phospho-mimetic cortactin mutations lead to filopodia-like structures, while phospho-null mutations disrupt F-actin binding.
- NEK9 and NEK7 activity causes cortactin-dependent morphological changes and migration in EML4-ALK V3-expressing cells.

## Abstract

EML4-ALK is a common oncogenic driver of non-small cell lung cancer. Distinct EML4-ALK variants cause different rates of disease progression, with patients expressing variant 3 (V3) exhibiting accelerated metastasis. Cells expressing EML4-ALK V3 develop a mesenchymal-like morphology and enhanced migration that is dependent on the NEK9 and NEK7 kinases. However, downstream substrates of these kinases relevant to these phenotypes are largely unknown. Here, we show that the actin-binding protein cortactin is phosphorylated by NEK7 within the F-actin-binding region (ABR) and that depletion of cortactin abrogates the morphological and migration phenotypes induced by EML4-ALK V3. Expression of constitutively active mutants of NEK9 or NEK7 causes similar cortactin-dependent morphological and migration changes. Cortactin co-localises with NEK7 and EML4-ALK V3 at branched filopodia-like extensions that are also generated upon expression of a cortactin protein with phospho-mimetic mutations in the ABR. In contrast, phospho-null mutations dissociate cortactin from F-actin. We propose that EML4-ALK V3 alters cell morphology and promotes directed cell migration by modulating the actin cytoskeleton via NEK7-mediated phosphorylation of cortactin within its ABR.

The online version contains supplementary material available at 10.1038/s41598-026-36484-4.