CLONING AND SEQUENCING OF CDNAS FOR RABBIT PREPROACROSIN AND A NOVEL PREPROACROSIN-RELATED CDNA

A 1414 bp cDNA for rabbit preproacrosin (RPA) and a related short prep roacrosin (shRPA) cDNA of 951 bp were cloned and sequenced. RPA's 431 amino acid open reading frame encodes a 46 422 kDa protein. shRPA is i dentical to RPA except that it lacks an internal stretch of 468 bp, su ch that the encoded protein has a deduced molecular mass of 29 965 kDa . Antiserum against a synthetic peptide representing the light chain o f rabbit proacrosin was used on Western blots of rabbit testis and spe rm. Under reducing conditions, it revealed two major groups of bands a t 50-57 and 29-32 kDa. Several lines of evidence suggest that shRPA is a splice variant of proacrosin and that it encodes a 30-33 kDa protei n similar to sperminogen (Siegel, M. et al. (1987) Biol. Reprod. 36, 1 063-1068), but apparently lacking proteinase activity.