Role of ACK1 condensates in STAT5 activation in LUSC cells

ACK1 is a non-receptor tyrosine kinase that phosphorylates multiple substrates involved in cancer progression. Additional regulatory mechanisms governing ACK1 activity remain to be elucidated. We demonstrate that ACK1 is frequently amplified and overexpressed in lung squamous cell carcinoma (LUSC). We found that ACK1 undergoes liquid-liquid phase separation (LLPS), a process dependent on the intrinsically disordered region (IDR, 96-156aa), but independent of its kinase activity. Our data also reveal that ACK1 phosphorylates STAT5 and promote STAT5 nuclear localization and transcriptional activity. To examine the gene regulation mediated by ACK1 condensates, we performed RNA-seq profiling of H2170 cells expressing GFP, ACK1 (WT)-GFP, or ACK1 (IDRmut)-GFP.