抄録
ENO1-'1acZ fusions with various lengths of the ENO1 5'-flanking region were constructed on various types of yeast plasmid vectors. The fully expressed level of βGal directed by ENO1-'1acZ fusions differed depending on the type of vector, but on any type of vector, βGal activity was not greatly influenced by the carbon source in the medium. The 86-bp DNA region of ENO1 at position -487 to -402 upstream of the initiation codon, in which we had previously delimited the positive regulatory region of ENO1 (Uemura, H., Shiba, T., Paterson, M., Jigami, Y., & Tanaka, H. (1986) Gene 45, 67-75), exerted its function without requiring precise location with respect to the TATA box. The action of the positive regulatory region was not affected by its orientation. In addition, the substitution of the UASs of PHO5, encoding repressible acid phosphatase, with the regulatory region of ENO1 changed the expression of PHO5-'lacZ gene to constitutive, irrespective of the concen-tration of inorganic phosphate in the medium. Furthermore, the GCR1 gene cloned in a multicopy plasmid increased the expression of the ENO1-'lacZ fused genes.
