Identification of a POU factor involved in regulating the neuron-specific expression of the gene encoding diapause hormone and pheromone biosynthesis-activating neuropeptide in Bombyx mori.
Diapause hormone (DH) and PBAN (pheromone biosynthesis-activating neuropeptide) are two important insect neuropeptides regulating development and reproduction respectively. In the present study, we report two Bombyx mori transcription factors interacting specifically with the promoter of Bom-DH-PBAN (where Bom-DH stands for B. mori DH); we named them DHMBP-1 and -2 (DH-modulator-binding proteins 1 and 2). The developmental changes of DHMBP-1/-2 are closely correlated with that of Bom-DH-PBAN mRNA throughout the pupal stage. Competition assays indicate that DHMBP-1 from Chinese B. mori possesses binding characteristics similar to those of the POU-M1 protein from Japanese B. mori. POU-M1 cDNAs were cloned from various tissues of Chinese B. mori and were found to be distinct from the previously published POU-M1 in amino acid residues 108-136 because of insertion mutations. Owing to this difference in amino acid residues, we named this cDNA POU-M2. Even though POU-M2 differs from POU-M1 at the N-terminal, the POU domain and the binding properties of both POU-M1 and -M2 are the same. Functional analysis showed that overexpression of POU-M2 in the Bombyx cell line BmN activated the promoter of Bom-DH-PBAN, but failed to activate a promoter in which the POU-binding element was mutated. The transcriptional activity of POU-M2 is probably regulated by other factors binding to the upstream of the promoter sequence. We show that the POU-M2-binding site was able to activate the transcription of a heterologous promoter of the gene encoding B. mori larval serum protein. POU-M1 was found to exhibit the same transcriptional activities as POU-M2. Taken together, these results demonstrate that POU-M2 plays an important role in the transcriptional regulation of the Bom-DH-PBAN gene.
Zhang
Tian-Yi
TY
Department of Molecular and Cell Biology, University of Science and Technology of China, Hefei 230027, People's Republic of China.
Kang
Le
L
Zhang
Zhi-Fang
ZF
Xu
Wei-Hua
WH
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000254:growth & development / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D019476:Insect Proteins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D007814:Larva; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000235:genetics; D009474:Neurons / Q000378:metabolism*; D009479:Neuropeptides / Q000096:biosynthesis* / Q000235:genetics; D050809:POU Domain Factors; D011401:Promoter Regions, Genetic; D011498:Protein Precursors / Q000096:biosynthesis* / Q000235:genetics; D017434:Protein Structure, Tertiary; D011679:Pupa; D011993:Recombinant Fusion Proteins / Q000502:physiology; D016415:Sequence Alignment; D017385:Sequence Homology; D013045:Species Specificity; D014157:Transcription Factors / Q000737:chemistry / Q000302:isolation & purification* / Q000502:physiology; D014158:Transcription, Genetic; D014162:Transfection
C092658:DH-PBAN precursor protein, Bombyx mori; D004268:DNA-Binding Proteins; D019476:Insect Proteins; D009419:Nerve Tissue Proteins; D009479:Neuropeptides; D050809:POU Domain Factors; C085604:POU-M1 protein, Bombyx mori; D011498:Protein Precursors; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; C075027:diapause hormone