The RMCE cassette in TI{TI}18wattP has been replaced with mutated 18w sequence, reconstituting a 18w locus in which the tyrosine residues in the C1 cluster of the C-terminal domain have been mutated so that they are non-phosphorylatable (this region is normally targeted by Src). In addition, the coding sequence is tagged at the C-terminal end with Tag:V5.