Abstract: 【Aim】 To screen the interacting proteins of RNA-binding protein RBP9 in the head of Drosophila melanogaster. 【Methods】 By using the CRISPR/Cas9 genome editing technology, the coding sequences of 3×Flag and V5 tag were inserted after the start codon ATG of RBP9 and FNE in the head of D. melanogaster adults, respectively, and 3×Flag-RBP9/3×Flag-RBP9 (3FRBP9) and V5-FNE/V5-FNE (VFNE) transgenic D. melanogaster strains were constructed. The interacting proteins of RBP9 in the head of adults of 3FRBP9 and the wild-type strain of D. melanogaster were identified by using immunoprecipitation and mass spectrometry and subjected to bioinformatics analysis. The interaction between RBP9 and FNE proteins was analyzed by immune coprecipitation method. 【Results】 A total of 190 proteins interacting with RBP9, including ELAV and FNE, were identified in the head of D. melanogaster adults by mass spectrometry. KEGG enrichment analysis showed that the genes of these proteins are mainly involved in ribosome, carbon metabolism, tricarboxylic acid cycle, biosynthesis of amino acids and other pathways. The results of immune coprecipitation test validated the interaction between RBP9 and FNE proteins. 【Conclusion】 RNA-binding proteins of the ELAV family interact with each other in the head of D. melanogaster adults. This study provides an important experimental basis for the further functional study of RBP9 in the nervous system development of Drosophila.

Key words: Drosophila melanogaster, RNA-binding protein, gene expression, mass spectrometry analysis, post-transcriptional regulation