Calcium Channel Flower Domain Containing Protein 1 (CACFD1)

Drosophila Flower protein associated with synaptic vesicles and localized at periactive zones upon synaptic vesicle fusion. Loss of Flower resulted in impaired intracellular resting Ca(2+) levels and impaired endocytosis. Flower formed multimers and formed a channel to control Ca(2+) influx in insect salivary gland cells. It also supported Ca(2+) influx in reconstituted proteoliposomes. Downregulation of Flower in Drosophila impaired Ca(2+) handling at presynaptic terminals.

Yao et al. (2009) cloned Drosophila Flower, and by database analysis they identified orthologs in several species, including mouse and human. The deduced 172-amino acid human protein contains 4 transmembrane domains conserved in Flower orthologs.