磷脂酰肌醇3-激酶在3-主要位置磷酸化磷脂酰肌醇的肌醇環。所述酶包括110 kD催化亞單位和85、55或50 kD調節亞單位。該基因編碼85kD調節亞單位。磷脂酰肌醇3激酶在胰島素的代謝作用中起著重要作用，該基因的突變與胰島素抵抗有關。這種基因的選擇性剪接導致四個轉錄變體編碼不同的亞型。
Phosphatidylinositol 3-kinase phosphorylates the inositol ring of phosphatidylinositol at the 3-prime position. The enzyme comprises a 110 kD catalytic subunit and a regulatory subunit of either 85, 55, or 50 kD. This gene encodes the 85 kD regulatory subunit. Phosphatidylinositol 3-kinase plays an important role in the metabolic actions of insulin, and a mutation in this gene has been associated with insulin resistance. Alternative splicing of this gene results in four transcript variants encoding different isoforms.