Progesterone synthesis by human placental mitochondria is sensitive to PKA inhibition by H89
Por:
Gomez-Concha, C, Flores-Herrera, O, Olvera-Sanchez, S, Espinosa-Garcia, MT, Martinez, F
Publicada:
1 sep 2011
Resumen:
The transfer of cholesterol to mitochondria, which might involve the phosphorylation of proteins, is the rate-limiting step in human placental steroidogenesis. Protein kinase A (PKA) activity and its role in progesterone synthesis by human placental mitochondria were assessed in this study. The results showed that PKA and phosphotyrosine phosphatase D1 are associated with syncytiotrophoblast mitochondrial membrane by an anchoring kinase cAMP protein-121. The (32)P-labeled of four major proteins was analyzed. The specific inhibitor of PKA, H89, decreased progesterone synthesis in mitochondria while in mitochondrial steroidogenic contact sites protein-phosphorylation was diminished, suggesting that PKA plays a role in placental hormone synthesis. In isolated mitochondria, PKA activity was unaffected by the addition of cAMP suggesting a constant activity of this kinase in the syncytiotrophoblast. The presence of PICA and phosphotyrosine phosphatase D1 anchored to mitochondria by an anchor
Filiaciones:
Univ Nacl Autonoma Mexico, Dept Bioquim, Fac Med, Mexico City 04510, DF, Mexico
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