Molecular cloning of a POU domain-containing factor involved in the regulation of the Bombyx sericin-1 gene.
The POU domain is a highly conserved region found in a number of transcription factors and products of developmental control genes. We report here the isolation and characterization of a POU domain-containing cDNA (POU-M1) from the middle silk gland of Bombyx mori. It encodes a protein with a POU domain identical to that of the Drosophila Cf1-a protein. By mobility shift and nuclease protection assays, the POU-M1 protein and the putative silk gland factor 3 (SGF-3) were found to interact in an indistinguishable manner with the SC region (positions -204 to -183) of the sericin-1 gene, a key cis-acting element involved in the regulation of the gene through the interaction with SGF-3. Antibodies raised against the synthetic oligopeptide corresponding to the COOH-terminal region of the putative POU-M1 sequence reacted specifically to both the POU-M1 protein and SGF-3. Northern blot hybridization and Western blotting revealed that POU-M1 expression is regulated both temporally and spatially during silk gland development. We conclude that the POU-M1 protein is SGF-3 and propose that the differential expression of the POU-M1 gene is probably involved in the transcriptional regulation of the silk protein genes.
Fukuta
M
M
National Institute for Basic Biology, Okazaki, Japan.
Matsuno
K
K
Hui
C C
CC
Nagata
T
T
Takiya
S
S
Xu
P X
PX
Ueno
K
K
Suzuki
Y
Y
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D012831:Bombyx / Q000235:genetics*; D003001:Cloning, Molecular; D017124:Conserved Sequence; D004247:DNA; D005786:Gene Expression Regulation; D005801:Genes, Homeobox; D008969:Molecular Sequence Data; D010456:Peptides, Cyclic / Q000096:biosynthesis* / Q000235:genetics*; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D012627:Sebaceous Glands / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D047030:Sericins; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*; D014158:Transcription, Genetic
D010456:Peptides, Cyclic; D047030:Sericins; D014157:Transcription Factors; D012313:RNA; D004247:DNA