PROTHYMOSIN-ALPHA IS NOT FOUND IN YEAST

According to published accounts, prothymosin alpha exhibits high evolu tionary conservation from yeast to man (Makarova, T., Grebenshikov, N. , Egorov, C., Vartapetian, A., and Bogdanov, A. FEES Lett. 257, 247-25 0, 1989). We report here our failure to find evidence for prothymosin alpha in yeast using three biochemical approaches: hybridization of ye ast mRNA and genomic DNA with human prothymosin a coding region probes , performance of the polymerase chain reaction with yeast genomic temp late DNA and three sets of primers recognizing human prothymosin a cod ing region sequences, and isolation of yeast proteins essentially as d escribed in the publication above. A survey of the Saccharomyces cerev isiae complete genome database using the program BLASTp verified our f indings: there is no prothymosin alpha-homologue in yeast. Furthermore , DNA representing organisms from bacteria to amphibians also failed t o hybridize with the same probes. Therefore, the presence of a prothym osin alpha gene in animals other than mammals is highly unlikely. (C) 1998 Academic Press.