Abstract: 【Aim】 Juvenile hormone response region (JHRR) is a 120 bp nucleotide sequence identified from the promoter regulatory region of Krüppel homolog1 (Kr-h1) in Drosophila. This study aims to detect the effects of three E-box like motifs (two B boxes and one C box) on the binding capacity of JHRR to nuclear proteins, and to illustrate the regulatory effects of JH, JH receptor-Methoprene-tolerant (Met) and heat shock protein Hsp83 on the binding capacity of JHRR to nuclear proteins. 【Methods】 The electrophoretic mobility shift assay (EMSA) was used to analyze the binding capacity of JHRR with two B boxes or one C box mutants to nuclear proteins in Kc cells. Nuclear proteins of fat body tissues, which were isolated from JH deficient flies (Aug21-GAL4>UAS-Grim), Met/Gce double mutant flies (Met²⁷gce^2.5k),Met overexpressed flies (Lsp2-GAL4>UAS-Met-V5) and Hsp83 homozygous mutant flies (Hsp^8308445) at the early wandering stage when the JH titer was high, were extracted, and the binding capacity of JHRR to nuclear proteins was detected by EMSA. 【Results】 EMSA results showed that both B box and C box mutation decreased the JH-induced binding capacity of JHRR to nuclear proteins in Kc cells, and the inhibitory effect of C box mutation was even more efficient. The binding complex of JHRR and nuclear proteins which were extracted from fat body tissues of JH deficient or Met/Gce double mutant larvae at the wandering stage was almost undetectable, and decreased significantly when the nuclear proteins were extracted from Hsp83 homozygous mutant larvae. In contrast, the formation of JHRR-nuclear protein complex was enhanced significantly when the nuclear proteins were extracted from fat body tissues of Met overexpressed larvae. 【Conclusion】 B box and C box are essential for JHRR to bind to nuclear proteins, and the binding activity of JHRR to nuclear proteins is dependent on JH and Met and regulated by Hsp83.

Key words: Drosophila melanogaster, juvenile hormone, Met, JHRR, Hsp83, nuclear protein binding