Decrease in phosphatidylserine synthesis in brain microsomes of Shambling mutant mouse

In the brain microsomes of the ataxic Shambling mutant mouse, the rate of phosphatidylserine (PS) synthesis was decreased to 60%, and that in the heterozygous nonataxic mutant, to 80%, of the control. By introducing calmodulin to the PS synthetic system, it was concluded that the decrease in PS synthesis in the ataxic mutant mouse corresponded to the amount of calmodulin-sensitive PS synthesis in control brain microsomes. Thyrotropin-releasing hormone (TRH), which is known to enhance locomotion of animals, also enhanced the rate of PS synthesis to compensate for the genetic defect in the rate of PS synthesis in vitro.