Karunaraj Prashath, Scheele Remkes, Wells Malcolm L, Rathod Ruchita, Abrahamson Sophia, Taylor Lila C, Gokulu Ipek S, Chowdhury Lamia, Kazmi Abiha, Song Weixiao, Hornbeck Peter, Li Jing, Glasgow Anum, Vasan Neil
Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA.
Department of Medicine, New York University Grossman School of Medicine, New York, NY, USA.
bioRxiv. 2025 Jun 16:2025.06.11.659120. doi: 10.1101/2025.06.11.659120.
SHP2 is a phosphatase and a critical mediator of receptor tyrosine kinase (RTK)-driven RAS/mitogen-activated protein kinase (MAPK) signaling. Despite promising preclinical data, SHP2 inhibitors have shown minimal clinical efficacy, with no defined clinical mechanisms of primary resistance. Here, we elucidate phosphorylation of SHP2 at tyrosine 62 (pY62) as a hotspot phosphorylation site in the proteome and RTK-driven tumor types in patients. We demonstrate that SRC family kinases directly phosphorylate SHP2 at Y62, downstream of but not directly phosphorylated by RTKs. Using biochemical and biophysical analyses, we show that SHP2 Y62D enforces an open, active conformation, resulting in constitutive phosphatase activation that is sufficient to activate MAPK signaling and confer resistance to allosteric SHP2 inhibitors. These findings establish that SHP2 pY62 is a phosphorylation hotspot phenocopying mutational activation, a mechanism of primary resistance to SHP2 inhibitors, and a cancer drug target distinct from wildtype SHP2.
SHP2是一种磷酸酶，是受体酪氨酸激酶（RTK）驱动的RAS/丝裂原活化蛋白激酶（MAPK）信号传导的关键介质。尽管临床前数据很有前景，但SHP2抑制剂的临床疗效甚微，且尚无明确的原发性耐药临床机制。在此，我们阐明了酪氨酸62位点（pY62）的SHP2磷酸化是蛋白质组和患者RTK驱动的肿瘤类型中的一个热点磷酸化位点。我们证明SRC家族激酶直接在Y62位点磷酸化SHP2，该位点位于RTK下游但不被RTK直接磷酸化。通过生化和生物物理分析，我们表明SHP2 Y62D导致一种开放的活性构象，从而导致组成型磷酸酶激活，足以激活MAPK信号传导并赋予对变构SHP2抑制剂的抗性。这些发现表明，SHP2 pY62是一种模拟突变激活的磷酸化热点，是对SHP2抑制剂原发性耐药的一种机制，也是一种不同于野生型SHP2的癌症药物靶点。
