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A polyclonal antibody was raised against bacterially produced catalytic αsubunit of protein phosphatase 2 A(PP2AC) cloned from Xenopusovarian library. The amount of PP2AC in Xenopusoocytes determined by Western blot analysis was 1 ng/μg of cytosolic protein. The antibody depleted PP2AC from oocyte extracts in association with 6 components (40, 62, 65, 80, 85 and 90 kDa). Prophase- and metaphase-arrested oocytes contained identical amounts of PP2AC. Metaphase oocytes showed one specific change in the 62 kDa protein associated with PP2AC.

This paper describes the purification of a 47 kDa protein from Xenopus laevisoocytes that becomes phosphorylated when the oocytes undergo meiotic maturation. This protein (p47) is part of a high molecular mass complex containing at least two other proteins of molecular mass 30 and 36 kDa. This complex can be isolated from stage VI oocytes before maturation. We obtained a pattern for phosphopeptides in p47 phosphorylated in vivo very similar to that of the purified protein phosphorylated in vitro by p34cdc2(a H1 kinase which is a component of the M‐phase promoting factor) and [γ‐32P]ATP. Therefore, the purified p47, already described as a marker of MPF activity, is the first reported in vivo substrate for the cell division control kinase.

A polyclonal antibody was raised against bacterially produced catalytic αsubunit of protein phosphatase 2A(PP2AC) cloned from Xenopusovarian library. The amount of PP2AC in Xenopusoocytes determined by Western blot analysis was 1 ng/μg of cytosolic protein. The antibody depleted PP2AC from oocyte extracts in association with 6 components (40, 62, 65, 80, 85 and 90 kDa). Prophase‐ and metaphase‐arrested oocytes contained identical amounts of PP2AC. Metaphase oocytes showed one specific change in the 62 kDa protein associated with PP2AC.

The complete amino acid sequence of the Ca 2+-triggered luciferin binding protein (LBP) of Renilla reniformishas been determined. The apoprotein has an unblocked amino terminus and contains 184 residues with a calculated Mrof 20541. LBP is a member of the EF-hand superfamily of Ca 2+-binding proteins and bears three predicted EF-hand domains. The sequence and organization of EF-hand domains are similar to those of the Ca 2+-dependent photoprotein, aequorin.

The complete amino acid sequence of the Ca2+‐triggered luciferin binding protein (LBP) of Renilla reniformishas been determined. The apoprotein has an unblocked amino terminus and contains 184 residues with a calculated Mrof 20541. LBP is a member of the EF‐hand superfamily of Ca2+‐binding proteins and bears three predicted EF‐hand domains. The sequence and organization of EF‐hand domains are similar to those of the Ca2+‐dependent photoprotein, aequorin.