Phospho-mTOR (Ser2448) Recombinant Rabbit mAb (S-3555)

Phospho-mTOR (Ser2448) refers to the phosphorylated form of the mammalian target of rapamycin (mTOR) at serine residue 2448, representing a key molecular marker of the activated state of mTOR complex 1 (mTORC1). This site is located within the C-terminal negative regulatory domain of mTOR and is primarily directly phosphorylated by the upstream PI3K-Akt signaling pathway—activated Akt kinase recognizes and modifies Ser2448, thereby partially relieving mTOR's intrinsic autoinhibition and enhancing its kinase activity toward downstream substrates such as S6K1 and 4E-BP1. Additionally, other kinases such as p38 MAPK and RSK can also contribute to the phosphorylation of this site under certain cellular conditions. Under physiological conditions, the phosphorylation level of Ser2448 dynamically reflects the cellular integration of growth factors, amino acids, and energy status, regulating protein synthesis, cell growth, and metabolic homeostasis. Pathologically, hyperphosphorylation of this site is commonly observed in various cancers (e.g., breast cancer, renal cancer, colorectal cancer), tuberous sclerosis complex, and overgrowth syndromes, closely associated with aberrant activation of the mTOR signaling pathway. In basic research and clinical applications, detecting Phospho-mTOR (Ser2448) is the most widely used biomarker for assessing mTORC1 activity.