Gene Networks Database

Strongylocentrotus purpuratus Genes in Development: Transcription Factors

SpGCF1

Function

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 loop DNA.
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).

Protein

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 N-terminal domain.
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).
GenBank: 755248

Subcellular location

Nuclear

Expression Pattern

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).

mRNA level

Temporal accumulation

Method: RNase protection assay
Reference: Zeller et al., 1995.

StageEgg 9 hr24 hr 36 hr48 hr 60 hr72 hr
Average No. transcripts/per embryo
5*10^3
8*10^3
4*10^3
5*10^3
3*10^3
2*10^3
1,5*10^3
Average No. transcripts/per cell
5*10^3
200
10
12
5
4,5
1-2

Sequences

GenBank:

Regulatory Regions

Regulatory Connections

Upstream Genes

SpGCF1

Endo16 CyIIIa SpAN SM30

Downstream Genes

Evolutionary homologues

Links

Bibliography
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Comments are welcome to Sveta Surkova
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