1997 Volume 9 Issue 1 Pages 57-65
We analyzed age-related changes of protein expression in rat brain cytosol to clarify proteins which might be involved in the development of the central nervous system. About 30 proteins that are expressed specifically at the prenatal stage were isolated from the cytosol fraction by preparative electrophoresis and subjected to amino acid sequence analysis. Although several of these fetal specific proteins, such as elongation factor-1 and HMG-1, which are known to be related to growth and differentiation have been characterized, the structure and function of almost all other proteins are still unknown. We purified and analyzed the partial sequence of one protein, p30, whose molecular weight was estimated to be 30 kDa on sodium dodecylsulf ate-polyacrylamide gel electrophoresis. The several partial amino acid sequences of the purified p30 were found to contain homologous sequences with Rho GDP-dissociation inhibitor and Ran binding protein 1, but other sequences were unidentified. The Rho GDP-dissociation inhibitor and Ran binding protein 1, with molecular weights of 27 kDa, regulate Rho and Ran, respectively, which are members of the ras p21-related small GTP-binding protein superf amily, and were separable from p30 on gel electrophoresis. Although the molecular mechanism of the action of p30 is still to be clarified, it might have an important role in the development of the central nervous system.
