Inhibition of phosphatidylinositol 3-kinase modifies boar sperm motion parameters

Involvement of Phosphatidylinositol 3-Kinase

Inhibition of phosphatidylinositol kinase by toyocamycin.

We have screened toyocamycin as an inhibitor of phosphatidylinositol kinase. It inhibited the enzyme of A431 cell membrane with an IC50 of 3.3 micrograms/ml. Adenosine and formycin A also inhibited the enzyme, but other 6 related nucleosides did not. Although orobol and 2,3-dihydroxybenzaldehyde that inhibit phosphatidylinositol kinase inhibited in situ phosphatidylinositol turnover, toyocamyci...

Calmodulin activates phosphatidylinositol 3-kinase.

Calmodulin and phosphatidylinositol 3-kinase are vital components of a number of common intracellular events. Calmodulin, a ubiquitous Ca2+-dependent effector protein, regulates multiple processes in eukaryotic cells, including cytoskeletal organization, vesicular trafficking, and mitogenesis. Phosphatidylinositol 3-kinase participates in events downstream of the receptors for insulin and other...

Inhibition of lymphocyte kinase Lck and phosphatidylinositol 3-kinase by a novel immunosuppressant, lymphostin.

Lck is a Src-family tyrosine kinase that is expressed predominantly in T cells, where it plays important roles in T-cell activation. Lymphostin was isolated from Streptomyces sp. as an inhibitor of Lck. As previously reported, lymphostin inhibited Lck (IC50 0.05 microM) and the mixed lymphocyte reaction (IC50 0.009 microM). We have now examined the mechanism of inhibition by lymphostin. Lymphos...

Increased phosphorylation of AKAP by inhibition of phosphatidylinositol 3-kinase enhances human sperm motility through tail recruitment of protein kinase A.

Sperm motility is regulated by a complex balance between kinases and phosphatases. Among them, phosphatidylinositol 3-kinase (PI 3-kinase) has been recently suggested to negatively regulate sperm motility (Luconi, M., Marra, F., Gandini, L., Lenzi, A., Filimberti, E., Forti, G. and Baldi, E. (2001). Hum. Reprod. 16, 1931-1937). We demonstrate the presence and activity of PI 3-kinase in human sp...