The CDK Pho85 inhibits Whi7 Start repressor to promote cell cycle entry in budding yeast.

Abstract in brief

• Pho85 is a key CDK in budding yeast that promotes cell cycle progression by targeting the Repressor Whi7, especially during the G1 to S phase transition.
• Pho85 inhibits Whi7 by phosphorylating it, which decreases its ability to bind to gene promoters, reduces its protein stability, and lowers WHI7 gene transcription, facilitating cell cycle entry.
• Under certain conditions, such as in the absence of Pho85, Whi7 becomes the primary repressor causing G1 arrest, highlighting Pho85's role in regulating Whi7 activity to coordinate environmental responses and cell cycle progression.]