目标雷帕霉素复合物1(TORC1)响应于多种输入信号调节真核细胞的生长。在酿酒酵母中,氨基酸通过由Gtr1和Gtr2以及EGO复合物(EGOC)中的Ego1和Ego3组成的Rag鸟苷三磷酸酶(GTPase)异二聚体激活TORC1。Gtr1的GTP酶活性受SEA复合物(SEAC)调节。具体来说,SEACIT,含有Iml1,Npr2和Npr3的SEAC亚复合物充当Gtr1的GTP酶激活剂(GAP),以降低TORC1的活性,因此,增长,氨基酸剥夺后。这里,我们提供遗传上位症数据,这表明Seacat,SEAC的另一个子复合体,含有Seh1,Sea2-4和Sec13,拮抗SEACIT的GAP功能。EGOC(Ragulator)的直系同源物,SEACIT(GATOR1),和SEACAT(GATOR2)存在于高等真核生物中,突出了非凡的保护,从酵母到人类,对RagGTPase和TORC1的调控。
The target of rapamycin complex 1 (TORC1) regulates eukaryotic cell growth in response to a variety of input signals. In S. cerevisiae, amino acids activate TORC1 through the Rag guanosine triphosphatase (GTPase) heterodimer composed of Gtr1 and Gtr2 found together with Ego1 and Ego3 in the EGO complex (EGOC). The GTPase activity of Gtr1 is regulated by the SEA complex (SEAC). Specifically, SEACIT, a SEAC subcomplex containing Iml1, Npr2, and Npr3 functions as a GTPase activator (GAP) for Gtr1 to decrease the activity of TORC1 and, consequently, growth, after amino acid deprivation. Here, we present genetic epistasis data, which show that SEACAT, the other SEAC subcomplex, containing
Seh1, Sea2-4, and Sec13, antagonizes the GAP function of SEACIT. Orthologs of EGOC (Ragulator), SEACIT (GATOR1), and SEACAT (GATOR2) are present in higher eukaryotes, highlighting the remarkable conservation, from yeast to man, of Rag GTPase and TORC1 regulation.