Signal transducing adapter molecule 1

Signal transducing adapter molecule 1 (STAM) is a 540-amino acid protein that mediates intracellular signal transduction downstream of cytokines and growth factors including IL-2 and GM-CSF, with roles in DNA synthesis, MYC induction, and T-cell development (UniProt: Q92783). It functions as part of the ESCRT-0 complex to recognize and sort ubiquitinated receptor tyrosine kinases toward lysosomal degradation via multivesicular bodies, and has also been implicated in dengue virus entry.

STAM is broadly expressed across tissues and participates in receptor downregulation and endosomal trafficking pathways (UniProt: Q92783). No baseline disease associations are documented in UniProt; however, the protein has been curated in the Chaparral dataset for Alzheimer's Disease relevance.

STAM is upregulated in Alzheimer's Disease brain tissue compared to age-matched controls, with a mean log2 fold-change of +0.62 (Chaparral AD proteomics). This elevation was detected in human post-mortem AD brain samples analyzed by TMT-labeled tandem mass spectrometry across multiple subcellular fractions, suggesting potential involvement in AD-related pathogenic processes, though the specific functional contribution remains to be elucidated.