Inositol monophosphatase 1

Inositol monophosphatase 1 is an is_associated_with::enzyme that in humans is encoded by the IMPA1 is_associated_with::gene.

Interacting partners
IMPA1 has been shown to interact with Bergmann glial is_associated_with::S100B and is_associated_with::calbindin.

Chemical inhibitors
L-690,330 is a competitive inhibitor of IMPase activity with very good activity is_associated_with::in vitro however with limited is_associated_with::bioavailability is_associated_with::in vivo. Due to its increased specificity compared to Lithium, L-690,330 has been used extensively in characterizing the results of IMPase inhibition in various cell culture models. L-690,488, a prodrug or L-690,330, has also been developed which has greater cell permeability. Treatment of cortical slices with L-690,488 resulted in accumulation of is_associated_with::inositol demonstrating the activity of this inhibitor in tissue.

Inhibition of IMPA1 activity can have is_associated_with::pleiotropic effects on cellular function, including altering is_associated_with::phosphoinositide signalling, is_associated_with::autophagy, is_associated_with::apoptosis, and other effects.

Bipolar disorder
Initially it was noticed that several drugs useful in treatment of biopolar disorder such as lithium, is_associated_with::carbamazepine and is_associated_with::valproic acid had a common mechanism of action on enzymes in the is_associated_with::phosphatidylinositol signalling pathway and the inositol depletion hypothesis for the pathophysiology of biopolar disorder was suggested. Intensive research has so far not confirmed this hypothesis, partly because lithium can also act on a number of other enzymes in this pathway, complicating results from is_associated_with::in vitro studies.