Identification of a functional element in the promoter of the silkworm (Bombyx mori) fat body-specific gene Bmlp3.
30K proteins are a group of structurally related proteins that play important roles in the life cycle of the silkworm Bombyx mori and are largely synthesized and regulated in a time-dependent manner in the fat body. Little is known about the upstream regulatory elements associated with the genes encoding these proteins. In the present study, the promoter of Bmlp3, a fat body-specific gene encoding a 30K protein family member, was characterized by joining sequences containing the Bmlp3 promoter with various amounts of 5' upstream sequences to a luciferase reporter gene. The results indicated that the sequences from -150 to -250bp and -597 to -675bp upstream of the Bmlp3 transcription start site were necessary for high levels of luciferase activity. Further analysis showed that a 21-bp sequence located between -230 and -250 was specifically recognized by nuclear factors from silkworm fat bodies and BmE cells, and could enhance luciferase reporter-gene expression 2.8-fold in BmE cells. This study provides new insights into the Bmlp3 promoter and contributes to the further clarification of the function and developmental regulation of Bmlp3.
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China.
Hanfu
H
Xu
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China; The Institute of Forensic Science, Chongqing Public Security Bureau, Chongqing 401147, China.
Dangjun
D
Deng
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China.
Lin
L
Yuan
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China.
Yuancheng
Y
Wang
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China.
Feng
F
Wang
State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China. Electronic address: xiaqy@swu.edu.cn.
Qingyou
Q
Xia
D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000235:genetics*; D004441:Ecdysterone / Q000494:pharmacology; D005216:Fat Body / Q000502:physiology*; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D007605:Juvenile Hormones / Q000494:pharmacology; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D024363:Transcription Initiation Site
D019476:Insect Proteins; D007605:Juvenile Hormones; D004441:Ecdysterone
30K protein; Bmlp3 promoter; Enhancer; Fat body; Silkworm