Two-dimensional electrophoretic analysis of major phosphoproteins of the sea urchin, Arbacia punctulata.

Phosphoproteins of hatched blastulae, gastrulae, and pluteus larvae of the sea urchin, Arbacia punctulata, were labeled in vivo with [32P]O4 and analysed by 2-dimensional polyacrylamide gel electrophoresis and autoradiography. At least 60 phosphoproteins were resolved. Some of these showed different relative intensities of labeling at the embryonic periods monitored. Some embryonic phosphoproteins were characterized by cell fractionation and by comparing autoradiograms with Coomassie-blue staining patterns and [35S]methionine labeling patterns. Neither actin nor tubulin phosphorylation was detected. No differences in phosphorylation were detected in dissociated and partially reassociated blastula cells relative to each other and to intact embryonic controls.