Signal Transduction Processes in the Developing Brain: Perturbations of G Protein Alpha-Subunit Abundances by Perinatal Hypothyroidism

Leung, Feng Chiao Lilian; Saggerson, E D; Clark, John B.

doi:10.1159/000111404

Cited by 3 publications

(1 citation statement)

References 30 publications

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“…Physiological relevance of these changes is not clear. Interestingly, no changes or a mild transient increase in G q α/G 11 α have previously been observed in the developing brain of hypothyroid immature rats [Wong et al, 1994; Leung et al, 1996].…”

Section: Discussionmentioning

confidence: 97%

Membrane‐bound and cytosolic forms of heterotrimeric G proteins in young and adult rat myocardium: Influence of neonatal hypo‐ and hyperthyroidism

Novotný

Bouřová²,

Kolář

et al. 2001

J of Cellular Biochemistry

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Membrane and cytosolic fractions prepared from ventricular myocardium of young (21-day-old) hypo- or hyperthyroid rats and adult (84-day-old) previously hypo- or hyperthyroid rats were analyzed by immunoblotting with specific anti-G-protein antibodies for the relative content of Gs alpha, Gi alpha/Go alpha, Gq alpha/G11 alpha, and G beta. All tested G protein subunits were present not only in myocardial membranes but were at least partially distributed in the cytosol, except for Go alpha2, and G11 alpha. Cytosolic forms of the individual G proteins represented about 5-60% of total cellular amounts of these proteins. The long (Gs alpha-L) isoform of Gs alpha prevailed over the short (Gs alpha-S) isoform in both crude myocardial membranes and cytosol. The Gs alpha-L/Gs alpha-S ratio in membranes as well as in cytosol increased during maturation due to a substantial increase in Gs alpha-L. Interestingly, whereas the amount of membrane-bound Gi alpha/Go alpha and Gq alpha/G11 alpha proteins tend to lower during postnatal development, cytosolic forms of these G proteins mostly rise. Neonatal hypothyroidism reduced the amount of myocardial Gs alpha and increased that of Gi alpha/Go alpha proteins. By contrast, neonatal hyperthyroidism increased expression of Gs alpha and decreased that of Gi alpha and G11 alpha in young myocardium. Changes in G protein content induced by neonatal hypo- and hyperthyroidism in young rat myocardium were restored in adulthood. Alterations in the membrane-cytosol balance of G protein subunits associated with maturation or induced by altered thyroid status indicate physiological importance of cytosolic forms of these proteins in the rat myocardium.

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Section: Discussionmentioning

confidence: 97%