Molecular cloning of a cDNA encoding 14-3-3 protein from the protozoan Tetrahymena pyriformis and its mRNA expression during synchronous division. 
The 14-3-3 proteins have been identified in a wide variety of eukaryotic cells and diverse biochemical properties have been ascribed to them.  Here we have cloned a cDNA encoding 14-3-3 protein from a cDNA library of Tetrahymena pyriformis.  This cDNA (Tp14-3-3) encoded an open reading frame consisting of 244 amino acids with predicated molecular mass as 28.1kDa.  The predicted protein shares 59.2%, 56.5% and 59.2% identity to Entamoeba histolytica 14-3-3-1, Schizosaccharomyces pombe Rad 24 and human 14-3-3 zeta/delta respectively.  On the basis of comparison with other 14-3-3 proteins, two of the putative functional domains (dimerization domain and annexin-similarity domain) were found in Tp14-3-3.  In order to know the role of Tp14-3-3 in Tetrahymena, its mRNA levels during synchronous division were examined by Northern blot analysis.  There was a marked increase in Tp14-3-3 mRNA level at 45min after the end of heat treatment, followed by a gradual decrease.  These results suggest that the Tp14-3-3 mRNA level might vary during the cell cycle.  The accumulation of Tp14-3-3 mRNA before cell division was assumed to be a prerequisite for the initiation of synchronous cell division.