Pho84Pho87

Pho84Pho87 is a protein complex found in yeast that plays a crucial role in phosphate homeostasis. Specifically, it is involved in the transport of inorganic phosphate across the plasma membrane. The complex is composed of two main subunits: Pho84, a high-affinity phosphate transporter, and Pho87, a low-affinity phosphate transporter. These two transporters work in concert to ensure the yeast cell has an adequate supply of phosphate, a vital nutrient for DNA, RNA, and ATP synthesis.

The activity of the Pho84Pho87 complex is tightly regulated by the cellular phosphate levels. When phosphate is scarce, the expression and activity of the complex are increased, allowing the cell to scavenge available phosphate efficiently. Conversely, when phosphate is abundant, the expression and activity are downregulated to prevent overaccumulation. This regulation is often mediated by signaling pathways that sense intracellular phosphate concentrations.

Mutations in the genes encoding Pho84 or Pho87 can lead to severe defects in phosphate uptake, impacting cell growth and viability. Understanding the function and regulation of the Pho84Pho87 complex is important for comprehending cellular nutrient sensing and transport mechanisms, with potential implications for understanding similar processes in other organisms. The complex is a model system for studying active phosphate transport and its cellular control.