Anchors cAMP-dependent protein kinase (PKA) and acts as an adapter protein to selectively couple G alpha-13 and Rho. Augments gene activation by the estrogen receptor in an element-specific and ligand-dependent manner. Activates estrogen receptor beta by a p38 MAPK-dependent pathway. Isoform 6 stimulates exchange activity on Rho proteins in vitro, but not on CDC42, Ras or Rac and may bind calcium ions.
Isoform 3 and isoform 6 are found in hematopoietic cells, skeletal muscle, lung, heart, estrogen-responsive reproductive tissues, including breast ductal epithelium. Also found in testis and breast cancer cell lines. Isoform 6 is not found in brain, placenta, liver, pancreas or kidney. Isoform 7 is expressed in myeloid and lymphoid lineages, a variety of epithelial tissues and skeletal muscle. Isoform 2 is predominantly found in the heart and at lower levels in the lung, placenta, kidney, pancreas, skeletal muscle and liver.