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Type: Artigo de periódico
Title: Novel Signal Transduction Pathway For Luteinizing Hormone And Its Interaction With Insulin: Activation Of Janus Kinase/signal Transducer And Activator Of Transcription And Phosphoinositol 3-kinase/akt Pathways.
Author: Carvalho, Carla R O
Carvalheira, José B C
Lima, Maria H M
Zimmerman, Suzana F
Caperuto, Luciana C
Amanso, Angélica
Gasparetti, Alessandra L
Meneghetti, Vainer
Zimmerman, Leonardo F
Velloso, Licio A
Saad, Mario J A
Abstract: The actions of LH are mediated through a single class of cell surface LH/human chorionic gonadotropin receptor, which is a member of the G protein-coupled receptor family. In the present study we showed that LH induced rapid tyrosine phosphorylation and activation of the Janus kinase 2 (JAK2) in rat ovary. Upon JAK2 activation, tyrosine phosphorylation of signal transducer and activator of transcription-1 (STAT-1), STAT-5b, insulin receptor substrate-1 (IRS-1), and Src homology and collagen homology (Shc) were detected. In addition, LH induced IRS-1/phosphoinositol 3-kinase and Shc /growth factor receptor-binding protein 2 (Grb2) associations and downstream AKT (protein kinase B, homologous to v-AKT) serine phosphorylation and ERK tyrosine phosphorylation, respectively. The simultaneous infusion of insulin and LH induced higher phosphorylation levels of JAK2, STAT5b, IRS-1, and AKT compared with each hormone alone in the whole ovary of normal rats. By immunohistochemistry we demonstrated that these late events take place in follicular cells and both external and internal theca. These results indicate a new signal transduction pathway for LH and show that there is positive cross-talk between the insulin and LH signaling pathways at the level of phosphoinositol 3-kinase/AKT pathway in this tissue.
Subject: Animals
Dna-binding Proteins
Insulin Receptor Substrate Proteins
Janus Kinase 2
Luteinizing Hormone
Milk Proteins
Mitogen-activated Protein Kinases
Phosphatidylinositol 3-kinases
Protein-serine-threonine Kinases
Protein-tyrosine Kinases
Proto-oncogene Proteins
Proto-oncogene Proteins C-akt
Rats, Wistar
Receptor Cross-talk
Stat1 Transcription Factor
Stat5 Transcription Factor
Signal Transduction
Src Homology Domains
Citation: Endocrinology. v. 144, n. 2, p. 638-47, 2003-Feb.
Rights: fechado
Identifier DOI: 10.1210/en.2002-220706
Date Issue: 2003
Appears in Collections:Unicamp - Artigos e Outros Documentos

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