Strongylocentrotus purpuratus Genes in Development:
Transcription Factors
SpOct
Function
SpOct is a single-copy gene that codes for
transcription factor which belongs to POU II family.
SpOct binds octamer elements
in the promoters of the H2B-alpha (Bell et al., 1992) and CyIIIa genes.
Protein
SpOct encodes a protein of 729 amino acids, whose predicted
molecular weight is 78 kDa.
The SpOct protein as a member of the POU domain family is characterized
by a highly conserved DNA-binding motif consisting of a 60- to 62-amino-acid
homeodomain and a 69- to 71-amino-acid sequence known as the POU-specific domain (Herr et al., 1988; Rosenfeld, 1991).
SpOct, like other members of the POU II family, possesses a glutamine-rich
domain in the N-terminal half, and a serine-threonine-rich domain at the
carboxy end. The glutamine-rich domain of SpOct has an unusually high
percentage of glutamines (50%) compared to similar proteins such
as Oct-1 (26%) (Sturm et al., 1988).
Subcellular location
Nuclear
Expression Pattern
Several SpOct transcripts are detected ranging in size from 4 to 12 kb,
all of which are present in embryos and in the adult.
SpOct transcripts are regulated coordinately in the embryo:
all are present at the low level in the
unfertilized egg, increase several-fold during cleavage and blastula formation, and
decline thereafter. SpOct mRNA levels peak in early blastula-stage
embryos, coincident with the maximum rate of a H2B-alpha
gene transcription and the maximum rate of nuclear DNA synthesis (Maxson and Wilt, 1981).
mRNA level
Temporal accumulation
Method: RNAase protection analysis
Reference: Char et al., 1993
Method: RNA gel blot analysis
Reference: Char et al., 1993