Gene Networks Database
Strongylocentrotus purpuratus Genes in
Development: Transcription Factors
SpGCF1 is a transcription factor that binds tightly to the certain
target site sequences surrounding a core CCCCN sequence,
where N is usually T.
It is a single-copy gene.
The SpGCF1 target sites (previously P8 and
P2) occur at least 38 times in the CyIIIa
and Endo16 promoters.
SpGCF1 is a general positive regulator of CyIIIa
and Endo16 genes (Zeller W. R.,1995).
The SpGCF1 target sites often lie close to sites where other
transcription factors bind.
SpGCF1 factor may act as an "intermodule communicator",
by virtue of its ability to multimerize and thereby
The SpGCF1 target sites also appear in the
regulatory domain of the SM30 sceletogenic gene.
Thus, SpGCF1 factor appears to interact with target
sites in the genes expressed in aboral ectoderm, vegetal plate and sceletogenic
terrritories (Zeller W. R.,1995).
A single SpGCF1 mRNA produces five polypeptides
which share a common DNA-binding domain and C-terminus
but differ at the N-terminus. The estimated size of
these polypeptides is 55, 50, 43, 40 and 37 kD.
The 55 kDa protein is 486 amino acids long. The
predicted amino acid sequence shows no significant
homologies with any known proteins. The amino-terminal
region contains nearly half of all of the methionine
residues present in the SpGCF1 protein. The first
methionine codon of the predicted ORF is
preceded by 4 in-frame stop codons. Four additional
methionines which encode SpGCF1 polypeptides are also
present in the amino-terminal region.
A proline-rich region, often implicated as functioning as
a transcriptional activation domain, is also located in
SpGCF1 forms higher multimeric complexes when bound to DNA probes,
as visualized in gel-shift experiments. In vitro SpGCF1
loops DNA bearing multiple binding sites (Zeller et al., 1995).
The SpGCF1 mRNA is detected in ovaries and is present
at about 5000 copies in the unfertilized egg, and
following a sharp decline, is present at about 10
molecules per average cell by 24 hr.
At 72 hr there are only about one or
two copies of SpGCF1 mRNA per cell.
The amount of mRNA per embryo peaks at about 9 hr
of development, when there are about 8000 molecules per
embryo, and then decreases to around 1500 copies at 72 hr (Zeller et al., 1995).
Method: RNase protection assay
Reference: Zeller et al., 1995.
||9 hr||24 hr
||36 hr||48 hr
||60 hr||72 hr
|Average No. transcripts/per embryo
|Average No. transcripts/per cell
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