Artículos de revistas
Multiple mechanisms of growth hormone-regulated gene transcription
Fecha
2007Registro en:
Ceseña, Teresa I.; Cui, Tracy Xiao; Piwien Pilipuk, Graciela; Kaplani, Julianne; Calinescu, Anda Alexandra; et al.; Multiple mechanisms of growth hormone-regulated gene transcription; Elsevier; Molecular Genetics And Metabolism; 90; 2; -1-2007; 126-133
1096-7192
1096-7206
CONICET Digital
CONICET
Autor
Ceseña, Teresa I.
Cui, Tracy Xiao
Piwien Pilipuk, Graciela
Kaplani, Julianne
Calinescu, Anda Alexandra
Huo, Jeffrey S.
Iñiguez Lluhí, Jorge A.
Kwok, Roland
Schwartz, Jessica
Resumen
Diverse physiological actions of growth hormone (GH) are mediated by changes in gene transcription. Transcription can be regulated at several levels, including post-translational modification of transcription factors, and formation of multiprotein complexes involving transcription factors, co-regulators and additional nuclear proteins; these serve as targets for regulation by hormones and signaling pathways. Evidence that GH regulates transcription at multiple levels is exemplified by analysis of the proto-oncogene c-fos. Among the GH-regulated transcription factors on c-fos, C/EBPbeta appears to be key, since depletion of C/EBPbeta by RNA interference blocks the stimulation of c-fos by GH. The phosphorylation state of C/EBPbeta and its ability to activate transcription are regulated by GH through MAPK and PI3K/Akt-mediated signaling cascades. The acetylation of C/EBPbeta also contributes to its ability to activate c-fos transcription. These and other post-translational modifications of C/EBPbeta appear to be integrated for regulation of transcription by GH. The formation of nuclear proteins into complexes associated with DNA-bound transcription factors is also regulated by GH. Both C/EBPbeta and the co-activator p300 are recruited to c-fos in response to GH, altering c-fos promoter activation. In addition, GH rapidly induces spatio-temporal re-localization of C/EBPbeta within the nucleus. Thus, GH-regulated gene transcription mediated by C/EBPbeta reflects the integration of diverse mechanisms including post-translational modifications, modulation of protein complexes associated with DNA and re-localization of gene regulatory proteins. Similar integration involving other transcription factors, including Stats, appears to be a feature of regulation by GH of other gene targets.