The p-alanyl-monoamine synthase ebony is regulated by schizophrenia susceptibility gene dysbindin in Drosophila

The Drosophila homolog of schizophrenia susceptibility gene dysbindin （Ddysb） affects a range of behaviors through regula- tion of multiple neurotransmitter signals, including dopamine activity. To gain insights into mechanisms underlying Ddysb-dependent regulation of dopamine signal, we investigated interaction between Ddysb and Ebony, the Drosophila β-alanyl-monoamine synthase involved in dopamine recycling. We found that Ddysb was capable of regulating expression of Ebony in a bi-directional manner and its subcellular distribution. Such regulation is confined to glial cells. The expression level of ebony and its accumulation in glial soma depend positively on Ddysb activity, whereas its distribution in glial processes is bound to be reduced in response to any alterations of Ddysb from the normal control level, either an increase or decrease. An optimal binding ratio between Dysb and Ebony might contribute to such non-linear effects. Thus, Ddysb-dependent regulation of Ebony could be one of the mechanisms that mediate dopamine signal.