We previously isolated the SKN7 gene in a screen designed to isolate new 
components of the G1-S cell cycle transcription machinery in budding yeast. We 
have now found that Skn7 associates with Mbp1, the DNA-binding component of the 
G1-S transcription factor DSC1/MBF. SKN7 and MBP1 show several genetic 
interactions. Skn7 overexpression is lethal and is suppressed by a mutation in 
MBP1. Similarly, high overexpression of Mbp1 is lethal and can be suppressed by 
skn7 mutations. SKN7 is also required for MBP1 function in a mutant compromised 
for G1-specific transcription. Gel-retardation assays indicate that Skn7 is not 
an integral part of MBF. However, a physical interaction between Skn7 and Mbp1 
was detected using two-hybrid assays and GST pulldowns. Thus, Skn7 and Mbp1 seem 
to form a transcription factor independent of MBF. Genetic data suggest that 
this new transcription factor could be involved in the bud-emergence process.