Blogotaxis

Big PIPin’

When it comes to movement, it’s all about phosphotidyl inositide phosphates (PIPs). At the leading edge of a moving cell, PI(3,4,5)P3 is there. Everywhere else is PI(4,5)P2. How does this happen? This means that the kinase (PI3K) must also be a the leading edge, and the phosphatase (PTEN) is everywhere else to prevent PI(3,4,5)P3 from forming in the wrong place. How does PTEN “know” to stay away from the leading edge?