Investigating the role of axonal localization of sex peptide receptor in post-mating responses of female Drosophila melanogaster

This study elucidates the molecular mechanisms underlying the axonal localization of the sex peptide receptor, a pivotal G-protein coupled receptor in the Drosophila melanogaster post-mating response cascade. Utilizing transgenic expression, neuronal labeling, and bioinformatics analyses, we demonstrate that the N-terminal domain of SPR is indispensable for its axonal targeting in both Drosophila larval ventral nerve cord neurons and mouse hippocampal neurons. Deletion of the N-terminal domain abolished axonal localization, highlighting its critical role in this process. Intriguingly, the C-terminal domain of SPR appears to play a subordinate role in axonal targeting. Bioinformatical analysis revealed a striking homology between the N-terminus of SPR and the Broad-complex, Tramtrack, and Bric-a-brac/poxvirus and zinc finger family of proteins. The BTB domain, a conserved protein-protein interaction domain within this family, is implicated in diverse cellular processes and axonal targeting. Further investigation into the role of the BTB domain-like region in SPR could provide valuable insights into the molecular underpinnings of axonal targeting and post-mating responses in Drosophila. This research contributes to our understanding of the intricate mechanisms governing GPCR localization and function in the context of reproductive biology and neuronal signaling.