Shams Raef, Ito Yoshihiro, Miyatake Hideyuki
Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science, Wako, Saitama 351-0198, Japan.
Department of Life Science, Graduate School of Science and Engineering, Saitama University, Saitama City, Saitama 338-8570, Japan.
ACS Omega. 2022 Jun 24;7(27):23479-23486. doi: 10.1021/acsomega.2c01865. eCollection 2022 Jul 12.
In cancer, the mechanistic/mammalian target of rapamycin complex-1 (mTORC1) is hyperactivated to promote survival under adverse conditions. The kinase activity of mTORC1 is activated by small-GTPase RHEB-GTP. Therefore, a new modality to inhibit mTORC1 activity has emerged, through intercepting RHEB. However, due to the relatively large contact area involved in the interaction between RHEB and mTORC1, facilitating this inhibition through small molecules has been challenging. Here, we report the development of a peptide that can inhibit the RHEB-mTORC1 interaction. The peptide, , was designed based on the α-helix (aa 101-115) of the N-heat domain of mTOR to interact with switch II of RHEB. bound to RHEB ( = 0.14 μM) and inhibited RHEB-mTOR interaction (IC = 0.33 μM) in vitro. Consequently, P1_WT inhibited mTORC1 activity at a sub-micromolar level (IC ∼ 0.3 μM). was predicted to be cell-permeable due to the rich content of arginine (23%), enhancing the intracellular translocation. These results show that is a potential compound to further develop inhibitors for mTORC1 by intercepting RHEB from mTORC1.
在癌症中，雷帕霉素作用机制/哺乳动物雷帕霉素靶蛋白复合物1（mTORC1）被过度激活，以促进在不利条件下的存活。mTORC1的激酶活性由小GTP酶RHEB-GTP激活。因此，通过拦截RHEB，出现了一种抑制mTORC1活性的新方法。然而，由于RHEB与mTORC1之间相互作用涉及的接触面积相对较大，通过小分子促进这种抑制一直具有挑战性。在这里，我们报告了一种能够抑制RHEB-mTORC1相互作用的肽的开发。该肽基于mTOR的N端热结构域的α螺旋（氨基酸101-115）设计，与RHEB的开关II相互作用。P1_WT在体外与RHEB结合（Kd = 0.14 μM）并抑制RHEB-mTOR相互作用（IC50 = 0.33 μM）。因此，P1_WT在亚微摩尔水平（IC50 ∼ 0.3 μM）抑制mTORC1活性。由于富含精氨酸（23%），P1_WT被预测具有细胞渗透性，增强了细胞内转运。这些结果表明，P1_WT是一种潜在的化合物，可通过从mTORC1中拦截RHEB进一步开发mTORC1抑制剂。
