1-NM-PP1

基本信息

产品描述

1-NM-PP1, a cell-permeable PP1 analog, is a potent Src family kinases inhibitor with IC50s of 4.3 nM and 3.2 nM for v-Src-as1 and c-Fyn-as1, respectively[1][2].

靶点（IC50 & Targe）

CDK7

体外研究

Cdk7 from Cdk7as/as or Cdk7+/+ cells is immunoprecipitated and tested its kinase activity towards both a Pol II CTD-containing fusion protein (GST-CTD) and human Cdk2. Cdk7 recovered from the mutant, but not the wild-type, cells is inhibited by 1-NM-PP1 (1-NMPP1), with an IC50 of ～50 nM with either substrate. Replacement of wild-type Cdk7 with Cdk7as/as also rendered growth of HCT116 cells sensitive to 1-NM-PP1. In the absence of 1-NM-PP1, the wild-type andCdk7as/as cells had population doubling times of ～17.9 and ～20.2 h, respectively, with similar cell-cycle distributions in asynchronous culture, indicating minimal impairment of Cdk7 function by the F91G mutation per se. The homozygous Cdk7as/as cells are sensitive to 1-NM-PP1, however, with an IC50 ～100 nM measured by cell viability (MTT) assays performed after 96 h of 1-NM-PP1 exposure. In contrast, wild-type HCT116 cells are resistant to 10 μM 1-NM-PP1. Addition of 10 μM 1-NM-PP1 retards G1/S progression by the mutant but not the wild-type cells. When added simultaneously with serum to the Cdk7as/as cells, 1-NM-PP1 prevents any progression into S phase in the next 15 h. After 24 h, there is evidence of progression into S-phase by a fraction of Cdk7as/as cells released from serum starvation directly into medium containing 1-NM-PP1, while a fraction remained in G1. The addition of 1-NM-PP1 3 h or 6 h after serum addition delays S-phase entry by ～7 h or by ～3 h, respectively[3].

激酶实验

Immunoblotting and immunoprecipitation, and kinase assays of immune complexes, are carried out. To measure Cdk1/cyclin B assembly, extracts (200 μg total protein) from cells in mitosis or G2 are pre-incubated with 2 μM 1-NM-PP1 or DMSO, then added 500 ng purified cyclin B1, amino-terminally tagged with hexahistidine and the Myc epitope, and an ATP-regenerating system. Where indicated, incubations are supplemented with 400 ng purified Csk1 or 600 ng wild-type or analog-sensitive, T-loop-phosphorylated Cdk7/cyclin H/Mat1 complex. After 90 min at room temperature, Myc-cyclin B and associated proteins are immunoprecipitated with anti-Myc antibodies and immune complexes are subjected to immunoblotting, with anti-Myc and anti-Cdk1 antibodies, and tested for histone H1 kinase activity[3].MCE has not independently confirmed the accuracy of these methods. They are for reference only.

细胞实验

Wild-type or Cdk7as/as HCT116 cells are synchronized by incubation in serum-free medium for 48 h and released into medium containing 10% fetal calf serum. Synchronization with thymidine or nocodazole, and analysis of cell-cycle distribution by flow cytometry, are performed. Cell viability is measured by MTT assay[3].MCE has not independently confirmed the accuracy of these methods. They are for reference only.

参考文献

[1]. Bishop A C, et al. Generation of Monospecific Nanomolar Tyrosine Kinase Inhibitors via a Chemical Genetic Approach. Journal of the American Chemical Society, 1999, 121(4):627-631.

[2]. Bishop AC, et al. A chemical switch for inhibitor-sensitive alleles of any protein kinase. Nature. 2000 Sep 21;407(6802):395-401.

[3]. Larochelle S, et al. Requirements for Cdk7 in the assembly of Cdk1/cyclin B and activation of Cdk2 revealed by chemical genetics in human cells. Mol Cell. 2007 Mar 23;25(6):839-50.