Abstract
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.
Original language | English |
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Pages (from-to) | 19471-19475 |
Number of pages | 5 |
Journal | Journal of Biological Chemistry |
Volume | 268 |
Issue number | 26 |
State | Published - 1993 |
Externally published | Yes |