SHC-Transforming Protein 1 (SHC1) Protein

Background

SHC1 is an adaptor protein that plays a critical role in linking receptor tyrosine kinases (RTKs) and cytokine receptors to downstream signaling pathways such as Ras/MAPK, PI3K/Akt, and JNK. It contains PTB and SH2 domains that mediate interactions with phosphorylated tyrosine residues on activated receptors, facilitating the recruitment of Grb2 and SOS to activate Ras signaling. SHC1 is widely expressed and is involved in cellular processes such as proliferation, survival, differentiation, and stress responses. It exists in multiple isoforms, including p46, p52, and p66, with p66 SHC1 acting as a redox sensor that regulates oxidative stress and apoptosis. Dysregulation of SHC1 contributes to cancer progression, as it enhances cell survival and proliferation through oncogenic signaling pathways, and has also been linked to aging and cardiovascular diseases. Knockout studies reveal defects in growth factor signaling, increased oxidative stress resistance, and reduced tumorigenesis, underscoring its dual role in promoting survival signaling and regulating cellular stress responses.