Possible involvement of Ca2+/calmodulin-dependent protein kinase in the regulation of phospholipid biosynthesis in Microsporum gypseum

The mechanism of action of Ca2+/calmodulin on phospholipid synthesis in Mic rosporum gypseum has been studied. These second messengers were observed to mediate their function through phosphorylation mechanism as altered protei n kinase activity was seen in calcium/trifluoperazine (calmodulin antagonis t) grown cells. The activity of protein kinase was dependent on calcium (20 0 mu m) and calmodulin (1 mu m). In vitro studies of phosphorylation and de phosphorylation in relation to phospholipid synthesis in Microsporum gypseu m have been carried out. Addition of KN-62 (a specific inhibitor of Ca2+/ca lmodulin-dependent protein kinases) and polyclonal antibodies raised agains t purified Ca2+/calmodulin-kinase (CaMPK) of M. gypseum in the cell extract , leads to the inhibition in the incorporation of labelled acetate into tot al phospholipids in this fungus. These results suggest a possible involveme nt of Ca2+/calmodulin via Ca2+/calmodulin-dependent phosphorylation in phos pholipid synthesis in M. gypseum.