The role of calcium/phospholipid-dependent protein kinase in Leydig cell steroidogenesis.

Abstract

Purified rat Leydig cell cytosol was found to contain a protein kinase which was dependent on the presence of both calcium and phospholipids (phosphatidylserine and diolein), i.e. calcium/phospholipid-dependent protein kinase. The peak of Ca/phospholipid-dependent protein kinase was separated from type I and type II cAMP-dependent protein kinase by DE-52 chromatography. 4 beta-Phorbol-12-myristate-13-acetate (PMA), a tumor-promoting agent, could substitute for diolein in activation of Ca/phospholipid-dependent protein kinase. PMA caused dose-dependent increments of testosterone formation by Leydig cells, whereas inactive phorbol esters had no significant effects. PMA-induced testosterone formation was dependent on extracellular calcium and could be blocked by the addition of the calcium channel-blocking agent nifedipine. Since PMA can directly activate Ca/phospholipid-dependent protein kinase and increase testosterone formation, these results suggest that Ca/phospholipid-dependent protein kinase may be involved in modulating Leydig cell steroidogenesis in addition to the classical cAMP-dependent protein kinase pathway.

• Authors: T Lin
• Journal: Endocrinology (Endocrinology) Vol. 117 Issue 1 Pg. 119-26 (Jul 1985) ISSN: 0013-7227 [Print] United States
• PMID: 2988910 (Publication Type: Comparative Study, Journal Article, Research Support, U.S. Gov't, Non-P.H.S.)

Chemical References

• Chorionic Gonadotropin
• Diglycerides
• Phosphatidylserines
• Phospholipids
• 8-Bromo Cyclic Adenosine Monophosphate
• Gonadotropin-Releasing Hormone
• Testosterone
• Cyclic AMP
• Protein Kinases
• Tetradecanoylphorbol Acetate
• Calcium
• diolein

Topics

• 8-Bromo Cyclic Adenosine Monophosphate (pharmacology)
• Animals
• Calcium (pharmacology)
• Chorionic Gonadotropin (pharmacology)
• Cyclic AMP (pharmacology)
• Diglycerides (pharmacology)
• Enzyme Activation (drug effects)
• Gonadotropin-Releasing Hormone (pharmacology)
• Leydig Cells (metabolism)
• Male
• Phosphatidylserines (pharmacology)
• Phospholipids (pharmacology)
• Protein Kinases (physiology)
• Rats
• Rats, Inbred Strains
• Testosterone (biosynthesis)
• Tetradecanoylphorbol Acetate (pharmacology)