SYAP1/BSTA Antibody #14077

Synapse-associated protein 1 (SYAP1) was originally described by its similarity to the Drosophila synapse-associated SAP47 protein (1). Subsequent research using a yeast two-hybrid system described the protein as a BSD domain–containing signal transducer and Akt interactor (BSTA) based on protein structure and function. The ubiquitously expressed BSTA protein contains a central BSD domain that may play a role in mediating interaction between the BSTA protein and the serine/threonine kinase Akt1 (2). Research studies support a model of Akt1 activation that involves interactions between the BSTA protein and both Akt1 and the mTORC2 kinase complex, followed by phosphorylation of both BSTA and Akt1 by mTORC2. This series of interactions and phosphorylation events is thought to result in phosphorylation of Akt1 at Ser473 and Akt1 kinase activation (2). The BSTA mediated phosphorylation of Akt1 may promote adipocyte differentiation by suppressing the expression of the transcription factor FoxC2 (2). Additional studies show that the estrogen receptor antagonist tamoxifen can regulate the expression of BSTA in some breast cancer cells, suggesting a possible role for BSTA in pathways related to response to tamoxifen and other chemopreventative agents (3).