Expression of the green fluorescent protein derivative S65T in Xenopus laevis oocytes

The coding region of the green fluorescent protein mutant S65T has been fused to the eukaryotic expression vector pMT3 and injected into the nucleus of Xenopus laevis oocytes. The fluorescent gene product is observed within 24-48 h and can be used as an internal control to monitor gene expression without the need for added substrates. Co-injection of pMT3-S65T and a pMT3 construct containing the coding region of the mouse cerebellar type 1 inositol 1,4,5-trisphosphate receptor (IP₃R) showed that the fluorescence level of S65T paralleled expression of IP₃R. This correlation makes it possible to visually evaluate relative levels of IP₃R expression.