scholarly journals Identification of a small molecule inhibitor that stalls splicing at an early step of spliceosome activation

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Anzhalika Sidarovich ◽  
Cindy L Will ◽  
Maria M Anokhina ◽  
Javier Ceballos ◽  
Sonja Sievers ◽  
...  
Keyword(s):  
Small Molecule ◽  
Intermediate Stage ◽  
Mrna Splicing ◽  
Molecule Inhibitor ◽  
Specific Proteins ◽  
Extensive Exchange ◽  
Dynamics And Function ◽  
Spliceosome Activation ◽  
And Function ◽  
Related Proteins

Small molecule inhibitors of pre-mRNA splicing are important tools for identifying new spliceosome assembly intermediates, allowing a finer dissection of spliceosome dynamics and function. Here, we identified a small molecule that inhibits human pre-mRNA splicing at an intermediate stage during conversion of pre-catalytic spliceosomal B complexes into activated Bact complexes. Characterization of the stalled complexes (designated B028) revealed that U4/U6 snRNP proteins are released during activation before the U6 Lsm and B-specific proteins, and before recruitment and/or stable incorporation of Prp19/CDC5L complex and other Bact complex proteins. The U2/U6 RNA network in B028 complexes differs from that of the Bact complex, consistent with the idea that the catalytic RNA core forms stepwise during the B to Bact transition and is likely stabilized by the Prp19/CDC5L complex and related proteins. Taken together, our data provide new insights into the RNP rearrangements and extensive exchange of proteins that occurs during spliceosome activation.

scholarly journals Neuron-based high-content assay and screen for CNS active mitotherapeutics

2020 ◽  
Vol 6 (2) ◽  
pp. eaaw8702 ◽  
Author(s):  
Boglarka H. Varkuti ◽  
Miklos Kepiro ◽  
Ze Liu ◽  
Kyle Vick ◽  
Yosef Avchalumov ◽  
...  
Keyword(s):  
Small Molecule ◽  
Hippocampal Neurons ◽  
Mitochondrial Dynamics ◽  
Synaptic Activity ◽  
Glutamate Toxicity ◽  
Primary Neurons ◽  
Screening Assay ◽  
Dynamics And Function ◽  
Small Molecule Modulators ◽  
And Function

Impaired mitochondrial dynamics and function are hallmarks of many neurological and psychiatric disorders, but direct screens for mitotherapeutics using neurons have not been reported. We developed a multiplexed and high-content screening assay using primary neurons and identified 67 small-molecule modulators of neuronal mitostasis (MnMs). Most MnMs that increased mitochondrial content, length, and/or health also increased mitochondrial function without altering neurite outgrowth. A subset of MnMs protected mitochondria in primary neurons from Aβ(1–42) toxicity, glutamate toxicity, and increased oxidative stress. Some MnMs were shown to directly target mitochondria. The top MnM also increased the synaptic activity of hippocampal neurons and proved to be potent in vivo, increasing the respiration rate of brain mitochondria after administering the compound to mice. Our results offer a platform that directly queries mitostasis processes in neurons, a collection of small-molecule modulators of mitochondrial dynamics and function, and candidate molecules for mitotherapeutics.

Abstract B060: Small molecule inhibitor of pre-mRNA splicing evokes antitumor activity via MDM4-p53 pathway

2018 ◽  
Author(s):  
Kazuho Nishimura ◽  
Masahiro Yaguchi ◽  
Yukiko Yamamoto ◽  
Shunsuke Ebara ◽  
Kawakita Yoichi ◽  
...  
Keyword(s):  
Antitumor Activity ◽  
Small Molecule ◽  
Small Molecule Inhibitor ◽  
Mrna Splicing ◽  
P53 Pathway ◽  
Molecule Inhibitor

scholarly journals ACH-806, an NS4A Antagonist, Inhibits Hepatitis C Virus Replication by Altering the Composition of Viral Replication Complexes

2013 ◽  
Vol 57 (7) ◽  
pp. 3168-3177 ◽  
Author(s):  
Wengang Yang ◽  
Yongnian Sun ◽  
Xiaohong Hou ◽  
Yongsen Zhao ◽  
Joanne Fabrycki ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Viral Replication ◽  
Small Molecule ◽  
Replication Complex ◽  
Direct Acting Antiviral ◽  
Molecule Inhibitor ◽  
Direct Acting ◽  
And Function ◽  
Further Development

ABSTRACTTreatment of hepatitis C patients with direct-acting antiviral drugs involves the combination of multiple small-molecule inhibitors of distinctive mechanisms of action. ACH-806 (or GS-9132) is a novel, small-molecule inhibitor specific for hepatitis C virus (HCV). It inhibits viral RNA replication in HCV replicon cells and was active in genotype 1 HCV-infected patients in a proof-of-concept clinical trial (1). Here, we describe a potential mechanism of action (MoA) wherein ACH-806 alters viral replication complex (RC) composition and function. We found that ACH-806 did not affect HCV polyprotein translation and processing, the early events of the formation of HCV RC. Instead, ACH-806 triggered the formation of a homodimeric form of NS4A with a size of 14 kDa (p14) both in replicon cells and in Huh-7 cells where NS4A was expressed alone. p14 production was negatively regulated by NS3, and its appearance in turn was associated with reductions in NS3 and, especially, NS4A content in RCs due to their accelerated degradation. A previously described resistance substitution near the N terminus of NS3, where NS3 interacts with NS4A, attenuated the reduction of NS3 and NS4A conferred by ACH-806 treatment. Taken together, we show that the compositional changes in viral RCs are associated with the antiviral activity of ACH-806. Small molecules, including ACH-806, with this novel MoA hold promise for further development and provide unique tools for clarifying the functions of NS4A in HCV replication.

scholarly journals Author response: Identification of a small molecule inhibitor that stalls splicing at an early step of spliceosome activation

2017 ◽  
Author(s):  
Anzhalika Sidarovich ◽  
Cindy L Will ◽  
Maria M Anokhina ◽  
Javier Ceballos ◽  
Sonja Sievers ◽  
...  
Keyword(s):  
Small Molecule ◽  
Small Molecule Inhibitor ◽  
Author Response ◽  
Early Step ◽  
Molecule Inhibitor ◽  
Spliceosome Activation

Inhibition of TMEM16A impedes embryo implantation and decidualization in mice

Reproduction ◽  
2018 ◽  
Author(s):  
Qianrong Qi ◽  
Yifan Yang ◽  
Kailin Wu ◽  
Qingzhen Xie
Keyword(s):  
Progesterone Receptor ◽  
Stromal Cells ◽  
Embryo Implantation ◽  
Mouse Uterus ◽  
Endometrial Stromal Cells ◽  
Uterine Endometrium ◽  
Molecule Inhibitor ◽  
Pathway Inhibition ◽  
And Function ◽  
Reproductive Processes

Recent studies revealed that TMEM16A is involved in several reproductive processes, including ovarian estrogen secretion and ovulation, sperm motility and acrosome reaction, fertilization, and myometrium contraction. However, little is known about the expression and function of TMEM16A in embryo implantation and decidualization. In this study, we focused on the expression and regulation of TMEM16A in mouse uterus during early pregnancy. We found that TMEM16A is up-regulated in uterine endometrium in response to embryo implantation and decidualization. Progesterone treatment could induce TMEM16A expression in endometrial stromal cells through progesterone receptor/c-Myc pathway, which is blocked by progesterone receptor antagonist or the inhibitor of c-Myc signaling pathway. Inhibition of TMEM16A by small molecule inhibitor (T16Ainh-A01) resulted in impaired embryo implantation and decidualization in mice. Treatment with either specific siRNA of Tmem16a or T16Ainh-A01 inhibited the decidualization and proliferation of mouse endometrial stromal cells. In conclusion, our results revealed that TMEM16A is involved in embryo implantation and decidualization in mice, compromised function of TMEM16A may lead to impaired embryo implantation and decidualization.

Sign in / Sign up

Export Citation Format

Share Document