Death-associated protein 1 (DAP1)

Death-associated protein 1 (DAP1) is a small, 15 kDa proline-rich protein that serves as a critical regulator of programmed cell death and cellular homeostasis. Originally identified as a positive mediator of interferon-gamma-induced apoptosis, it is now characterized as an intrinsically disordered protein and a direct substrate of the mechanistic target of rapamycin complex 1 (mTORC1). Under nutrient-replete conditions, mTORC1 phosphorylates DAP1 at Ser3 and Ser51 to functionally silence its activity; however, during starvation or pharmacological mTOR inhibition, DAP1 is dephosphorylated and acts as a potent suppressor of autophagy to prevent excessive autophagic flux. In the context of human disease, DAP1 is frequently downregulated in various cancers, including breast, colorectal, and pancreatic malignancies, where its low expression is often associated with poor clinical outcomes and increased metastatic potential. While direct small-molecule inhibitors of DAP1 are not yet in clinical use, its activity is modulated by rapalogs such as sirolimus and everolimus. Understanding the dual role of DAP1 in managing the balance between apoptosis and autophagy makes it a significant candidate for therapeutic targeting in both oncology and neurodegenerative disorders.

Other names

DAPDAP-115 kDa proline-rich protein