The sluggish-A gene of Drosophila melanogaster is expressed in the nervous system and encodes proline oxidase, a mitochondrial enzyme involved in glutamate biosynthesis.
Hayward DC, Delaney SJ, Campbell HD, Ghysen A, Benzer S, Kasprzak AB, Cotsell JN, Young IG, Miklos GL. Proc Natl Acad Sci U S A. 1993 Apr 1; 90(7):2979-83.