A functional siRNA screen identifies genes modulating angiotensin II-mediated EGFR transactivation

作者：George Amee J; Purdue Brooke W; Gould Cathryn M; Thomas Daniel W; Handoko Yanny; Qian Hongwei; Quaife Ryan Gregory A; Morgan Kylie A; Simpson Kaylene J; Thomas Walter G^*; Hannan Ross D

来源：Journal of Cell Science, 2013, 126(23): 5377-5390.

DOI：10.1242/jcs.128280

• Angiotensin
• EGFR
• G protein-coupled receptor
• siRNA
• Transactivation

The angiotensin type 1 receptor (AT(1)R) transactivates the epidermal growth factor receptor (EGFR) to mediate cellular growth, however, the molecular mechanisms involved have not yet been resolved. To address this, we performed a functional siRNA screen of the human kinome in human mammary epithelial cells that demonstrate a robust AT(1)R-EGFR transactivation. We identified a suite of genes encoding proteins that both positively and negatively regulate AT(1)R-EGFR transactivation. Many candidates are components of EGFR signalling networks, whereas others, including TRIO, BMX and CHKA, have not been previously linked to EGFR transactivation. Individual knockdown of TRIO, BMX or CHKA attenuated tyrosine phosphorylation of the EGFR by angiotensin II stimulation, but this did not occur following direct stimulation of the EGFR with EGF, indicating that these proteins function between the activated AT(1)R and the EGFR. Further investigation of TRIO and CHKA revealed that their activity is likely to be required for AT(1)R-EGFR transactivation. CHKA also mediated EGFR transactivation in response to another G protein-coupled receptor (GPCR) ligand, thrombin, indicating a pervasive role for CHKA in GPCR-EGFR crosstalk. Our study reveals the power of unbiased, functional genomic screens to identify new signalling mediators important for tissue remodelling in cardiovascular disease and cancer.

• 出版日期2013-12-1