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Browsing by Author "Lane, Brandon S."
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Item Exploring the Existing Drug Space for Novel pTyr Mimetic and SHP2 Inhibitors(American Chemical Society, 2015-07-09) He, Rongjun; Yu, Zhi-Hong; Zhang, Ruo-Yu; Wu, Li; Gunawan, Andrea M.; Lane, Brandon S.; Shim, Joong S.; Zeng, Li-Fan; He, Yantao; Chen, Lan; Wells, Clark D.; Liu, Jun O.; Zhang, Zhong-Yin; Department of Biochemistry & Molecular Biology, IU School of MedicineProtein tyrosine phosphatases (PTPs) are potential therapeutic targets for many diseases. Unfortunately, despite considerable drug discovery efforts devoted to PTPs, obtaining selective and cell permeable PTP inhibitors remains highly challenging. We describe a strategy to explore the existing drug space for previously unknown PTP inhibitory activities. This led to the discovery of cefsulodin as an inhibitor of SHP2, an oncogenic phosphatase in the PTP family. Crystal structure analysis of SHP2 interaction with cefsulodin identified sulfophenyl acetic amide (SPAA) as a novel phosphotyrosine (pTyr) mimetic. A structure-guided and SPAA fragment-based focused library approach produced several potent and selective SHP2 inhibitors. Notably, these inhibitors blocked SHP2-mediated signaling events and proliferation in several cancer cell lines. Thus, SPAA may serve as a new platform for developing chemical probes for other PTPs.Item The regulation of the serum response network by the RGS RHOGEFS is critical for YAP1 activity and cell fate decisions(2017-07) Lane, Brandon S.; Wells, Clark D.The growth of mammary epithelial cells is regulated by interactions with neighboring cells and by exposure to soluble factors including hormones and growth factors. These cues are integrated within the cell, perpetuating changes onto the organization of the actin cytoskeleton, resulting in altered transcriptional programs. Rho family GTPases regulates actin dynamics that facilitate transcriptional reprogramming. In particular, RhoA induces the formation of actin stress fibers to promote the transcriptional co-activator YAP1 to translocate from the cytosol into the nucleus. There, it co-activates TEAD family transcription factors to drive the expression of pro-growth and survival genes. Rho family members are activated by guanine exchange factors (GEF) and inhibited by GTPase activating proteins (GAP). Here, we determined the relative effects of expression of 67 RhoGEFs and RhoGAPs on the activation of TEAD. This revealed that regulator of G-protein signaling (RGS) domain containing ArhGEF1, ArhGEF11 and ArhGEF12 all promoted YAP1 dependent activation of TEAD. These RhoGEFs mediate signaling from heptahelical receptors that are stimulated by lipid mitogens to activate the heterotrimeric G-proteins Gα12 and Gα13. Consistently, loss of expression of ArhGEF12 and to a lesser degree ArhGEF11 prevented actin stress fiber accumulation and activation of YAP1 mediated signaling by serum. Conversely, several complementary experiments revealed that ArhGEF1 dominantly limits Gα13 selective activation of YAP1 and the mitogen activated protein kinase (MAPK) cascades. Furthermore excessive Gα13 activity results in both high levels of filamentous actin and arrest cells in the G1/0 phase of the cell cycle. This is likely due to the systemic inhibition of cell cycle promoting signaling and a loss of protein translation. Further, YAP1 was found to be essential for the survival of ArhGEF1 silenced cells. Together, these studies define a circuit whereby the rgRhoGEFs regulate Gα 12/13-RhoA signaling flux to regulate cellular growth that is promoted by serum factors.Item The RGS-RhoGEFs control the amplitude of YAP1 activation by serum(Springer Nature, 2021-01-27) Lane, Brandon S.; Heller, Brigitte; Hollenberg, Morley D.; Wells, Clark D.; Biochemistry and Molecular Biology, School of MedicineActin-dependent mechanisms drive the nuclear translocation of Yap1 to enable its co-activation of transcription factors that induce pro-growth and survival programs. While Rho GTPases are necessary for the nuclear import of YAP1, the relevant Guanine Exchange Factors (GEFs) and GTPase Activating Proteins (GAPs) that connect this process to upstream signaling are not well defined. To this end, we measured the impact of expressing sixty-seven RhoGEFs and RhoGAPs on the YAP1 dependent activity of a TEAD element transcriptional reporter. Robust effects by all three members of the regulator of G-protein signaling (RGS) domain containing RhoGEFs (ArhGEF1, ArhGEF11 and ArhGEF12) prompted studies relating their known roles in serum signaling onto the regulation of Yap1. Under all conditions examined, ArhGEF12 preferentially mediated the activation of YAP1/TEAD by serum versus ArhGEF1 or ArhGEF11. Conversely, ArhGEF1 in multiple contexts inhibited both basal and serum elevated YAP1 activity through its GAP activity for Gα13. The sensitivity of such inhibition to cellular density and to low states of serum signaling supports that ArhGEF1 is a context dependent regulator of YAP1. Taken together, the relative activities of the RGS-RhoGEFs were found to dictate the degree to which serum signaling promotes YAP1 activity.Item Therapeutic Potential of Targeting the Oncogenic SHP2 Phosphatase(American Chemical Society, 2014-08-14) Zeng, Li-Fan; Zhang, Ruo-Yu; Yu, Zhi-Hong; Li, Sijiu; Wu, Li; Gunawan, Andrea M.; Lane, Brandon S.; Mali, Raghuveer S.; Li, Xingjun; Chan, Rebecca J.; Kapur, Reuben; Wells, Clark D.; Zhang, Zhong-Yin; Department of Biochemistry & Molecular Biology, IU School of Medicine, The Src homology 2 domain containing protein tyrosine phosphatase-2 (SHP2) is an oncogenic phosphatase associated with various kinds of leukemia and solid tumors. Thus, there is substantial interest in developing SHP2 inhibitors as potential anticancer and antileukemia agents. Using a structure-guided and fragment-based library approach, we identified a novel hydroxyindole carboxylic acid-based SHP2 inhibitor 11a-1, with an IC50 value of 200 nM and greater than 5-fold selectivity against 20 mammalian PTPs. Structural and modeling studies reveal that the hydroxyindole carboxylic acid anchors the inhibitor to the SHP2 active site, while interactions of the oxalamide linker and the phenylthiophene tail with residues in the β5–β6 loop contribute to 11a-1’s binding potency and selectivity. Evidence suggests that 11a-1 specifically attenuates the SHP2-dependent signaling inside the cell. Moreover, 11a-1 blocks growth factor mediated Erk1/2 and Akt activation and exhibits excellent antiproliferative activity in lung cancer and breast cancer as well as leukemia cell lines.