Role of DOR/TP53INP2 in the control of muscle protein degradation = Papel de DOR/TP53INP2 en el control de la degradación de proteínas en el músculo esquelético

[eng] Protein homeostasis (proteostasis) results from the fine regulation of synthesis and degradation. The nuclear cofactor DOR/TP53INP2 was identified originally as a protein expressed in PML of nuclear bodies. However, in response to cellular stress, DOR/TP53INP2 exits the nucleus, localizes to early autophagosomes and regulates autophagy. Recent data from our laboratory has demonstrated that DOR promotes muscle wasting by the activation of basal autophagy in skeletal muscle. Aim of this project is to analyze the role of DOR/TP53INP2 in combining the regulation of autophagy with other muscle homeostatic processes like the Ubiquitin- Proteasome System. Our results indicate that DOR is a negative regulator of the proteasome activity in C2C12 cells and skeletal muscle. Our data suggest that this upregulation of the proteasome activity in DOR-deficient cells is modulated by an induction of some subunits of the proteasome such as PSMD4 and PSMD11, subunits of the 19S regulatory particle involved in the recognition of Ub and proteasome assembly. Moreover, results suggest that DOR is also a negative regulator of protein synthesis. The comprehension of DOR function in regulating proteostasis will potentially identify new targets against muscle atrophy. Indeed, DOR expression is repressed in wasting conditions such as diabetes and cancer cachexia. ; [spa] La homeostasis de proteinas (proteostasis) resulta de una buena regulación de la síntesis y degradación proteica. El cofactor nuclear DOR/TP53INP2 fue identificado originariamente como una proteina expresada en PML de nuclear bodies. Sin embargo, en respuesta a estrés celular, DOR/TP53INP2 sale del núcleo, localiza con autofagosomas tempranos y regula la autofagia. Datos recientes de nuestro laboratorio han demostrado que DOR/TP53INP2 promueve la perdida de masa muscular por la activación de autofagia basal en el músculo esquelético. El objetivo de este proyecto es analizar el papel de DOR/TP53INP2 como regulador que interconecta la autofagia con otros procesos ...