Does not act as a Rho1- or Rho-family GTPase-specific biosensor; the encoded protein binds to both GDP- and GTP-bound Rho1, Cdc42, and, to a lesser extent, Rac1.

The Ubi-p63E promoter drives expression of the Rho1 GTP-binding domain of scra (amino acids 748-1239 are present), tagged at the C-terminal end with a GSSGSS linker followed by mEGFP(A206K). This protein acts as a sensor for the activity of Rho1.