Temporal activation of the sea urchin late H1 gene requires stage-specific phosphorylation of the embryonic transcription factor SSAP.

ABSTRACT: Stage-specific activator protein (SSAP) is a 41-kDa polypeptide that binds to embryonic enhancer elements of the sea urchin late H1 gene. These enhancer elements mediate the transcriptional activation of the late H1 gene in a temporally specific manner at the mid-blastula stage of embryogenesis. Although SSAP can transactivate the late H1 gene only at late stages of the development, it resides in the sea urchin nucleus and maintains DNA binding activity throughout early embryogenesis. In addition, it has been shown that SSAP undergoes a conversion from a 41-kDa monomer to a approximately 80- to 100-kDa dimer when the late H1 gene is activated. We have demonstrated that SSAP is differentially phosphorylated during embryogenesis. Serine 87, a cyclic AMP-dependent protein kinase consensus sit

SUBMITTER: Li Z 

PROVIDER: S-EPMC84181 | biostudies-literature | 1999 May

REPOSITORIES: biostudies-literature