1,4,5-ip3

FLA-99 is a biochemical compound that selectively inhibits the enzymatic breakdown of inositol-1,4,5-triphosphate (IP3) by inositol-1,4,5-triphosphate 5-phosphatase. By preventing IP3 degradation, FLA-99 modulates intracellular calcium signaling, making it a useful tool in signal transduction and phosphoinositide pathway research.

BHPI is a potent inhibitor of nuclear estrogen receptor ERα–regulated gene expression that induces sustained ERα-dependent activation of the endoplasmic reticulum stress sensor and unfolded protein response, leading to persistent inhibition of protein synthesis, and in ERα-positive cancer cells it hyperactivates plasma membrane PLCγ to generate IP3, deplete ER calcium stores via IP3R channels, and convert the normally protective UPR into a toxic response, making BHPI a valuable probe for estrogen signaling and ER stress–based cancer research.

D-myo-Inositol 1,4,5-trisphosphate hexapotassium salt is a second messenger that promotes the release of calcium ions from the endoplasmic reticulum.

ARN 11391 enhances the function of the IP3-gated calcium channel ITPR1 (Inositol 1,4,5-trisphosphate (IP3) receptor type 1), boosting intracellular calcium ion signaling by directly targeting ITPR1. Furthermore, ARN 11391 amplifies calcium signaling in cells with mutant ITPR1 linked to SCA29, a variant of spinocerebellar ataxia.

Xestospongins and araguspongins, marine natural products originally isolated from sponges in the Pacific basin, exhibit vasodilatory effects. Inositol phosphates (IP) serve as crucial signal transduction messengers, activating IP3 receptors to facilitate Ca2+ release from intracellular stores. Araguspongin B specifically hinders the calcium-releasing function of inositol 1,4,5-trisphosphate at the receptor level within cerebral microsomes, demonstrating an inhibition concentration (IC50) of 0.6 µM. This potency places it nearly on par with xestospongin C in obstructing the IP3 receptor's activity.