FIG. 5.

Mutants of full-length MTK1 that can interact with MKK6 in the absence of GADD45. Yeast L40 cells were transformed with an ACT-MTK1 construct (pACT-MTK1-FL wild type or one of its derivatives, as indicated on the figure) and a common DB-MKK6-K/A construct (pBTM-MKK6-K/A). Transformed yeast cells were spread on the appropriate synthetic agar plates supplemented with (+His) or without (−His) histidine. Mutations are designated by a one-letter amino acid code: L534Q, for example, stands for a mutation of leucine at the 534th amino acid position to glutamine. ACT-MTK1(1309-1607), which contains only the MTK1 kinase catalytic domain, was used as a positive control.