an overexpression of SENP1, which promotes prostate cancer progression as well as metastasis. Therefore, SENP1 has been identified as a novel drug target against prostate cancer. Herein, we report the discovery and biological evaluation of potent and selective SENP1 inhibitors. A structure-activity relationship (SAR) of the newly identified pyridone scaffold revealed allosteric inhibitors with very
Mapping the Protein Interaction Landscape for Fully Functionalized Small-Molecule Probes in Human Cells
作者:Tohru Kambe、Bruno E. Correia、Micah J. Niphakis、Benjamin F. Cravatt
DOI:10.1021/ja505517t
日期:2014.7.30
Phenotypicscreening provides a means to discover small molecules that perturb cell biological processes. Discerning the proteins and biochemical pathways targeted by screening hits, however, remains technically challenging. We recently described the use of small molecules bearing photoreactive groups and latent affinity handles as fully functionalized probes for integratedphenotypicscreening and
Serine/threonine protein kinase ULK3 is implicated in a variety of cellular processes, including autophagy, cell division, and execution of the Sonic hedgehog pathway. However, very little about how its biological activity could be controlled is known. This study focuses on unraveling biochemical insights into the mechanism of inhibition and activation of ULK3. We identify novel phosphorylation sites in ULK3 and show that autophosphorylation has no impact on the kinase activity of the protein. We further demonstrate that phosphorylation of two residues in the kinase domain of ULK3 by an as yet unidentified kinase may completely abolishes its catalytic activity. We show that a low-molecular weight inhibitor SU6668, designed as an ATP competitive inhibitor for tyrosine kinases, binds in the ATP pocket of ULK3 yet inhibits ULK3 kinase activity in a partially ATP noncompetitive manner. Finally, we demonstrate that the ULK3 kinase domain, annotated in silico, is not sufficient for its kinase activity, and additional amino acids in the 271–300 region are required.
丝氨酸/苏氨酸蛋白激酶 ULK3 参与多种细胞过程,包括自噬、细胞分裂和 Sonic Hedgehog 通路的执行。然而,人们对如何控制其生物活性知之甚少。本研究的重点是揭示 ULK3 抑制和激活机制的生化见解。我们鉴定了 ULK3 中的新磷酸化位点,并表明自磷酸化对该蛋白的激酶活性没有影响。我们进一步证明,ULK3 激酶结构域中的两个残基被一种尚未鉴定的激酶磷酸化可能会完全消除其催化活性。我们发现,一种低分子量抑制剂 SU6668,被设计为酪氨酸激酶的 ATP 竞争性抑制剂,结合在 ULK3 的 ATP 口袋中,但以部分 ATP 非竞争性方式抑制 ULK3 激酶活性。最后,我们证明,计算机注释的 ULK3 激酶结构域不足以发挥其激酶活性,需要 271-300 区域中的额外氨基酸。