TY - JOUR
T1 - Gonadotropins induce rapid phosphorylation of the 3',5'-cyclic adenosine monophosphate response element binding protein in ovarian granulosa cells
AU - Mukherjee, Abir
AU - Park-Sarge, Ok Kyong
AU - Mayo, Kelly E.
PY - 1996
Y1 - 1996
N2 - The pituitary gonadotropins FSH and LH exert their effects on gonadal target cells, at least in part, through the activation of adenylyl cyclase and the production of the second messenger cAMP. To elucidate further the signal transduction pathways regulating gonadotropin-responsive genes in ovarian granulosa cells, we have investigated the expression of the cAMP response element binding protein (CREB), which mediates many of the effects of cAMP by modulating the transcription of target genes in a cAMP-dependent fashion. In situ hybridization, RNA blot analysis and RT-PCR RNA quantification demonstrated that CREB messenger RNA (mRNA) is expressed at low levels throughout the ovary, and that CREB mRNA levels do not change appreciably after gonadotropin stimulation. Similar results were obtained using immunohistochemistry and Western protein blotting to examine CREB protein in ovaries isolated from immature animals treated with gonadotropins or immunocytochemistry and Western protein blotting to examine the CREB protein in cultured granulosa cells after gonadotropin treatment. In contrast, immunocytochemistry and Western protein blotting using an antipeptide antibody specific to CREB phosphorylated at serine 133 (P-CREB), which is the activated form of the CREB protein, revealed a dramatic increase in the phosphorylated form of CREB within 20 min of gonadotropin treatment of granulosa cells that was transient and was decreased by 60 min after gonadotropin treatment. Stimulation of P-CREB was observed using granulosa cells isolated from immature animals and treated with recombinant human FSH in vitro, or using granulosa cells isolated from immature animals primed with PMSG in vivo and treated with human CG (hCG) in vitro. Stimulation of P-CREB was also observed in ovarian granulosa cells isolated from animals treated with PMSG in vivo. These results indicate that both gonadotropins can induce a rapid and transient phosphorylation of the CREB protein in granulosa cells, leading to the activation of a factor likely to play an important role in the transcription of many gonadotropin-regulated ovarian genes.
AB - The pituitary gonadotropins FSH and LH exert their effects on gonadal target cells, at least in part, through the activation of adenylyl cyclase and the production of the second messenger cAMP. To elucidate further the signal transduction pathways regulating gonadotropin-responsive genes in ovarian granulosa cells, we have investigated the expression of the cAMP response element binding protein (CREB), which mediates many of the effects of cAMP by modulating the transcription of target genes in a cAMP-dependent fashion. In situ hybridization, RNA blot analysis and RT-PCR RNA quantification demonstrated that CREB messenger RNA (mRNA) is expressed at low levels throughout the ovary, and that CREB mRNA levels do not change appreciably after gonadotropin stimulation. Similar results were obtained using immunohistochemistry and Western protein blotting to examine CREB protein in ovaries isolated from immature animals treated with gonadotropins or immunocytochemistry and Western protein blotting to examine the CREB protein in cultured granulosa cells after gonadotropin treatment. In contrast, immunocytochemistry and Western protein blotting using an antipeptide antibody specific to CREB phosphorylated at serine 133 (P-CREB), which is the activated form of the CREB protein, revealed a dramatic increase in the phosphorylated form of CREB within 20 min of gonadotropin treatment of granulosa cells that was transient and was decreased by 60 min after gonadotropin treatment. Stimulation of P-CREB was observed using granulosa cells isolated from immature animals and treated with recombinant human FSH in vitro, or using granulosa cells isolated from immature animals primed with PMSG in vivo and treated with human CG (hCG) in vitro. Stimulation of P-CREB was also observed in ovarian granulosa cells isolated from animals treated with PMSG in vivo. These results indicate that both gonadotropins can induce a rapid and transient phosphorylation of the CREB protein in granulosa cells, leading to the activation of a factor likely to play an important role in the transcription of many gonadotropin-regulated ovarian genes.
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U2 - 10.1210/endo.137.8.8754745
DO - 10.1210/endo.137.8.8754745
M3 - Article
C2 - 8754745
AN - SCOPUS:0029896186
SN - 0013-7227
VL - 137
SP - 3234
EP - 3245
JO - Endocrinology
JF - Endocrinology
IS - 8
ER -