Fig. 4.

Scheme depicting the proposed role of IP6K1 as a metabolic sensor in both physiology and pathophysiology. (A) Glucose regulates IP6K1 mediated production of IP₇ via the ATP/ADP ratio and contributes to first phase insulin secretion (right graph). (B) Red text and drawing indicate how multiple genetic and environmental factors may converge on cellular metabolism to disrupt ATP/ADP regulation, thus disturbing IP₇ production and leading to increased basal secretion and reduced first phase insulin secretion. (C) Two aspects of the diabetic phenotype, increased basal insulin secretion and reduced responsiveness to glucose stimulation could be underscored by the transmission of defective metabolism into disturbed IP₇ production. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)