RESUMEN
Identification and characterization of factors regulating intracellular localization of the androgen receptor (AR) are fundamentally important because nucleocytoplasmic trafficking of AR is a critical step in AR regulation by androgen manipulation. Normally, AR is localized to the cytoplasm in the absence of androgen. Upon ligand binding, AR translocates to the nucleus, where it can modulate transcription of AR-responsive genes. The withdrawal of androgen results in the export of unliganded AR from the nucleus to the cytoplasm, where it is transcriptionally inactive. Calreticulin has been implicated as a possible nuclear export factor for AR because the two proteins form a complex. In this study, we assessed whether the cytoplasmic localization of AR requires binding to calreticulin. To test this we substituted the calreticulin binding sequence (CBS) KVFFKR (residues 579-584) with the amino acids RLAARK in AR and monitored the cellular localization of a GFP-AR fusion protein in the absence of androgen. We also determined if knockdown or knockout of calreticulin expression affected the cytoplasmic localization of the AR. We found that a mutated CBS did not affect the localization of AR and that in the absence of androgen, AR is localized to the cytoplasm regardless of its ability to interact with calreticulin. Also, a reduction in the levels or loss of calreticulin did not affect the localization of AR. These data argue that calreticulin is not required for the cytoplasmic localization of AR.
Asunto(s)
Calreticulina/metabolismo , Citoplasma/metabolismo , Neoplasias de la Próstata/metabolismo , Receptores Androgénicos/metabolismo , Sitios de Unión , Calreticulina/genética , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Técnicas de Silenciamiento del Gen , Humanos , Masculino , Poro Nuclear/metabolismo , Proteínas Nucleares/metabolismo , Neoplasias de la Próstata/genética , Neoplasias de la Próstata/fisiopatologíaRESUMEN
The availability of extracorporeal membrane oxygenation (ECMO) is the standard of care at most high-acuity congenital heart surgery programs. Extracorporeal membrane oxygenation is also an integral part of managing children with in-hospital cardiac arrest refractory to conventional cardiopulmonary resuscitation (extracorporeal cardiopulmonary resuscitation). In this article, we aim to provide a practical guide to initiate rapid ECMO in a nonoperating room setting.