CELL BIOLOGY: GSK-3ß and Microtubule Assembly in Axons -- Zhou and Snider 308 (5719): 211 -- Science:
Two papers recently published in Cell (3, 4), together with other recent work, suggest that glycogen synthase kinase 3ß (GSK-3ß) is a crucial player in the regulation of axon morphogenesis downstream of phosphatidylinositol 3-kinase (PI3K) signaling. First purified in 1980, GSK-3ß is a serine/threonine kinase that mediates the inactivation of glycogen synthase. Surprisingly, GSK-3ß has emerged as a key regulatory kinase in the nervous system with involvement in processes ranging from neural development to mood stabilization to neurodegeneration.
These are studies on the shared microtubule arrangements of neurons. More on microtubules back here
. This is common descent, and it generates evolutionary hypotheses about these proteins.