Kumar Amit, Schwab Michael, Laborit Labrada Beisy, Silveira Maruhen Amir Datsch, Goudreault Marilyn, Fournier Éric, Bellmann Kerstin, Beauchemin Nicole, Gingras Anne-Claude, Bilodeau Steve, Laplante Mathieu, Marette André
Faculté de Médecine, Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec (CRIUCPQ), Université Laval, Québec, Quebec, Canada.
Centre de Recherche du CHU de Québec - Université Laval, Axe Oncologie, Québec, Quebec, Canada; Centre de Recherche sur le Cancer de l'Université Laval, Québec, Quebec, Canada; Département de biologie moléculaire, biochimie médicale et pathologie, Faculté de Médecine, Université Laval, Québec, Quebec, Canada.
J Biol Chem. 2023 Sep;299(9):105164. doi: 10.1016/j.jbc.2023.105164. Epub 2023 Aug 16.
We previously reported that the protein-tyrosine phosphatase SHP-1 (PTPN6) negatively regulates insulin signaling, but its impact on hepatic glucose metabolism and systemic glucose control remains poorly understood. Here, we use co-immunoprecipitation assays, chromatin immunoprecipitation sequencing, in silico methods, and gluconeogenesis assay, and found a new mechanism whereby SHP-1 acts as a coactivator for transcription of the phosphoenolpyruvate carboxykinase 1 (PCK1) gene to increase liver gluconeogenesis. SHP-1 is recruited to the regulatory regions of the PCK1 gene and interacts with RNA polymerase II. The recruitment of SHP-1 to chromatin is dependent on its association with the transcription factor signal transducer and activator of transcription 5 (STAT5). Loss of SHP-1 as well as STAT5 decrease RNA polymerase II recruitment to the PCK1 promoter and consequently PCK1 mRNA levels leading to blunted gluconeogenesis. This work highlights a novel nuclear role of SHP-1 as a key transcriptional regulator of hepatic gluconeogenesis adding a new mechanism to the repertoire of SHP-1 functions in metabolic control.
我们之前报道过蛋白酪氨酸磷酸酶SHP-1(PTPN6)对胰岛素信号传导起负调节作用,但其对肝脏葡萄糖代谢和全身血糖控制的影响仍知之甚少。在此,我们运用免疫共沉淀分析、染色质免疫沉淀测序、计算机方法和糖异生分析,发现了一种新机制,即SHP-1作为磷酸烯醇式丙酮酸羧激酶1(PCK1)基因转录的共激活因子,以增加肝脏糖异生。SHP-1被招募至PCK1基因的调控区域并与RNA聚合酶II相互作用。SHP-1被招募至染色质取决于其与转录因子信号转导和转录激活因子5(STAT5)的结合。SHP-1以及STAT5的缺失会减少RNA聚合酶II对PCK1启动子的招募,进而降低PCK1 mRNA水平,导致糖异生减弱。这项研究突出了SHP-1作为肝脏糖异生关键转录调节因子的新的核作用,为SHP-1在代谢控制中的功能增添了一种新机制。