Gene-targeting reveals physiological roles and complex regulation of the phosphoinositide 3-kinases.

Phosphoinositide 3-kinases (PI3Ks) are represented by a family of eight distinct enzymes that can be divided into three classes based on their structure and function. The class I PI3Ks are heterodimeric enzymes that are regulated by recruitment to plasma membrane following receptor activation and which control numerous cellular functions, including growth, differentiation, migration, survival, and metabolism. New light has been shed on the biological role of individual members of the class I PI3Ks and their regulatory subunits through gene-targeting experiments. In addition, these experiments have brought the complexity of how PI3K activation is regulated into focus.