Postnatal development of Gαo isoforms in rat cerebral cortex was studied by SDS-PAGE and immunoblotting. When rat cerebral cortical membranes were resolved on separating gels containing 9% acrylamide and 8 M urea, three electrophoretically distinct Gαo-immunoreactive proteins were evident. Comparison of their electrophoretic mobilities and partial tryptic digest pattern with recombinant Gαo1 or Gαo1-specific antibody revealed that the slowest and intermediate-migrating bands represent unmodified and fatty acylated forms of Gαo1 protein, respectively. The fastestmigrating band corresponds to Gαo2. While the fatty acylated form of Gαo1 is the predominant species, its appearance paralleled that observed for Gαo2 in developing rat cortex. Perinatal hypothyroidism induced by methimazole treatment did not significantly alter the appearance of cerebral cortical Gαo1 and Gαo2 between days 1 and 22 postpartum. Our findings support the earlier idea that heterogeneity of Gαo proteins in mammalian brain is likely the result of different co- or post-translational processings of each splice variant of Gαo. While the appearance of Gαo isoforms is developmentally regulated, they likely do not play an obligatory role in neonatal brain development. Alternatively, the expression of Gαo isoforms in developing rat cortex may be controlled by an intrinsic signal(s) that is independent of the thyroid status.
- Go α-subunits
- Perinatal Hypothyroidism
ASJC Scopus subject areas
- Cellular and Molecular Neuroscience