PhosphoPlus^® TAZ (Ser89) Antibody Duet

Background

TAZ is a transcriptional co-activator with a PDZ-binding motif that is regulated by its interaction with 14-3-3 proteins (1). TAZ shares homology with the WW domain of Yes-associated protein (YAP) (1). TAZ is proposed to modulate the switch between proliferation and differentiation of mesenchymal stem cells (MSC) via interaction with transcription factors Runx2 and PPARγ. This process is critical to normal tissue development and the prevention of tumor formation. Due to its role in determination of MSC fate, TAZ may have clinical relevance to several human diseases caused by an imbalance of MSC differentiation (2,3). TAZ is negatively regulated via phosphorylation by LATS1/2, core kinases in the Hippo signaling pathway that controls stem cell development, tissue growth and tumor development (4).
Phosphorylation of TAZ at Ser89 functions to destabilize TAZ protein by promoting 14-3-3 binding, cytoplasmic sequestration, and proteasomal degradation, thereby reducing the ability of TAZ to co-activate transcription of downstream target genes. Mutation of Ser89 to alanine (S89A) yields a constitutively active form of TAZ; expression of TAZ (S89A) in breast cancer cells was shown to promote a cancer stem cell phenotype (5).