STRUCTURAL AND FUNCTIONAL DIVERSITY OF PHOSPHOINOSITIDE 3-KINASES

Phosphoinositide 3-kinases (PI3-kinases) have been shown to be recruit ed to cell surface receptor signal complexes whose formation is trigge red by growth factors, cytokines and other ligands. PI3-kinases are al so involved in protein sorting phenomena. A number of PI3-kinase isoty pes have been characterised in several laboratories. Here the relation s between the PI3-kinases, PI4-kinases and PI5-kinases and other poten tial phosphoinositide kinases are analysed. A study of the relation of structure to function for sequence motifs defined through the use of homology searches and protein modelling techniques is described and us ed to assign the family of phosphoinositide kinases to subgroups.