A disruption-replacement approach for the targeted integration of foreign genes in Hansenula polymorpha.

A system has been developed which allows the selection of integrative transformants with replacement of the Hansenula polymorpha methanol oxidase gene (MOX) with expression cassettes carrying heterologous gene under the control of the MOX promoter. The system is convenient for comparison of the expression levels of different constructs integrated into the same locus of the H. polymorpha genome. This system was used to compare the secretion levels of human urinary plasminogen activator, the secretion of which was directed by different signal sequences.