@misc{oai:ir.soken.ac.jp:00001296,
author = {福田, 雅一 and フクタ, マサカズ and FUKUTA, Masakazu},
month = {2016-02-17, 2016-02-17},
note = {The POU domain is a DNA-binding regionconsisting of 75-82
amino acids POU-specific domain, a short variable linker region and
a POU-homeodomain of 60 amino acids (for a review,seeRuvkin and
Finny, 1991). It was originarry found in three mammalian
transcription factors, the pituitary-specific Pit-1/GHF-1,the
ubiquitous Oct-1 and the predominantly B cell specific Oct-2, and
the product of the cell lineage control gene Unc-86 of Caenorhadbitis
elegans (Herr et al.,1988 and references therein).
By means of
sequence similarity, several other mammalian POU domain genes have
also been identified (He et al., 1989; Monouki et al., 1990; Okamoto
et al., 1990; Rosner et al., 1990 Scholer et al., 1990; Suzuki et al.,
1990). All of them were shown to interact with an octamer-like
sequence and to activate transcription via an octamer motif near the
TATA box.The Drosophila Cfl-a protein,which interants with a DNA
element required for expression of the dopa decarboxylase gene in
selected dopaminergic neurons (Johnson and Hirsh,1990), was also
found to posses a POU domain similar to those of the mouse Oct-6
(Suzuki et al.,1990) and the humann Brn-1 and Brn-2 (He et al.,1898)
proteins. These POU domain genes are likely regulatory genes
controlling transcription of distinct sets of genes during develop-
ment. The finding that two dwarf mutations in mice are null mutations
in the Pit-1/GHF-1 gene (Li et al., 1990) provide further support on
the roles of POU transcription factors in development. Recently, the
mternally expressed POU transcription factor, the Oct-3/4
protein (Okamoto et al., 1990; Scholer et al., 1990), has also been
shown to be required for the first embryonic cell division in mice
(Rosner et al., 1990).
Suzuki and his colleagues have been studying the developmental
regulation of the silk protein genes in Bonbyx mori (Suzuki et al.,
1990). Among them, the siricin-1 gene is expressed exclusively in the
middle silk gland while the fibroin gene is specific to the posterior
silk gland. Both genes are actively expressed during the intermolt
but repressed during the molting stages. Several silk gland protins
have been identified as putative regulatoly factors involved in the
transcriptioal control of the fibroin and scrin-1 genes ( Hui et al.,
1990; Matsuno et al., 1989,1990). One of these proeins , SGF-3, was
found to bind with high affinity to the SC region of the sericin-1 gene
and the distal upstream reion of the fibroin gene (Hui et al., 1990).
These regions are known to be important for an efficient transcription
in the silk gland extracts. Amultimer of the SC region gave
transcriptional enhancement in extracts prepared from the middle silk
gland where the sericin-1 gene is specifically epressed but that of a
mutant SC region giving a reduced affinity for SGF-3 did not (Matsuno
et al., 1990). Mobility shift assay revealed that SGF-3 is far more
abundant in the silk gland of the 2-day-old fifth-instar larvae than in
the pasterior silk gland (Hui et al., 1990; Matsuno et al., 1990; Y.
Suzuki, unpublised). These obaervations suggest that the SGF-3 is a key
regulatory factor in the transcription control ol the sericin-1 gene.
The SGF-3 was supposed as an octamer binding protein (Hui et al.,
1990). Since high affnitiy SGF-3 binding sites, such as the SC and
fibroin distal upstream regions, also contain octamer-like sequences,
it has been speculated that SGF-3 might possess a POU domain similar
to the mammalian octamer-binding proteins. This repoort presents here
the isolation and characterization of a POU domain containg cDNA
(POU-M1) from the middle silk gland. It encodes a protein with a POU
domain identical to that of the Drosophila Cfl-a protein. By mobility
shift assay and nuclease protection assay, the POU-M1 protein and the
putative silk gland factor SGF-3 were found to interact in an
indistinguishable manner with the SC region of the sericin-1 gene,
which is a key cis-acting element involved in the stimulation of
sercin-1 gene transcription through the interaction with SGF-3.
Antibodies raised against the synthetic oligopeptides correponding
to the two regions of putative POU-M1 protein reacted specifically to
both the POU-M1 protein and SGF-3. Northern blot hybridization
and Western blotting revealed that the POU-M1 expression is regulated
both temporally and spatially during the silk gland development. It
is concluded that the POU-M1 proein is identical to the SGF-3 and
proposed that the differential expression of the POU-M1 gene is probably
involved in the transcriptional regulation of the silk protein genes., application/pdf, 総研大甲第26号},
title = {カイコセリシン-１遺伝子の制御に関わるＰＯＵドメインを持つ転写因子のクローニング},
year = {}
}