Life Sciences Commons^™

Targeting The Brd4/Foxo3a/Cdk6 Axis Sensitizes Akt Inhibition In Luminal Breast Cancer, Jingyi Liu, Weijie Guo, Zhibing Duan, Lei Zeng, Yadi Wu, Yule Chen, Fang Tai, Yifan Wang, Yiwei Lin, Qiang Zhang, Yanling He, Jiong Deng, Rachel L. Stewart, Chi Wang, Pengnian Charles Lin, Saghi Ghaffari, B. Mark Evers, Suling Liu, Ming-Ming Zhou, Binhua P. Zhou, Jian Shi

Molecular and Cellular Biochemistry Faculty Publications

BRD4 assembles transcriptional machinery at gene super-enhancer regions and governs the expression of genes that are critical for cancer progression. However, it remains unclear whether BRD4-mediated gene transcription is required for tumor cells to develop drug resistance. Our data show that prolonged treatment of luminal breast cancer cells with AKT inhibitors induces FOXO3a dephosphorylation, nuclear translocation, and disrupts its association with SirT6, eventually leading to FOXO3a acetylation as well as BRD4 recognition. Acetylated FOXO3a recognizes the BD2 domain of BRD4, recruits the BRD4/RNAPII complex to the CDK6 gene promoter, and induces its transcription. Pharmacological inhibition of either BRD4/FOXO3a association or …

Structure Of The Mouse Trpc4 Ion Channel, Jingjing Duan, Jian Li, Bo Zeng, Gui-Lan Chen, Xiaogang Peng, Yixing Zhang, Jianbin Wang, David E. Clapham, Zongli Li, Jin Zhang

Molecular and Cellular Biochemistry Faculty Publications

Members of the transient receptor potential (TRP) ion channels conduct cations into cells. They mediate functions ranging from neuronally mediated hot and cold sensation to intracellular organellar and primary ciliary signaling. Here we report a cryo-electron microscopy (cryo-EM) structure of TRPC4 in its unliganded (apo) state to an overall resolution of 3.3 Å. The structure reveals a unique architecture with a long pore loop stabilized by a disulfide bond. Beyond the shared tetrameric six-transmembrane fold, the TRPC4 structure deviates from other TRP channels with a unique cytosolic domain. This unique cytosolic N-terminal domain forms extensive aromatic contacts with the TRP …

Direct Cell-To-Cell Transmission Of Respiratory Viruses: The Fast Lanes, Nicolás P. Cifuentes-Muñoz, Rebecca Ellis Dutch, Roberto Cattaneo

Molecular and Cellular Biochemistry Faculty Publications

Virus particles protect genomes from hostile environments within and outside the host, eventually delivering these genomes to target tissues to initiate infection. Complex processes requiring significant energy and time are necessary to assemble these virus particles, but only a small portion of released virus will successfully infect new target cells (Fig 1A). While the science of virology has developed based on the isolation and purification of viral particles, it is becoming increasingly clear that direct cell-to-cell transmission of viruses and/or viral components is also highly relevant [1,2].

Direct cell-to-cell spread of infections has several advantages. The first is efficiency: genomic …

Structure Of Full-Length Human Trpm4, Jingjing Duan, Zongli Li, Jian Li, Ana Santa-Cruz, Silvia Sanchez-Martinez, Jin Zhang, David E. Clapham

Molecular and Cellular Biochemistry Faculty Publications

Transient receptor potential melastatin subfamily member 4 (TRPM4) is a widely distributed, calcium-activated, monovalent-selective cation channel. Mutations in human TRPM4 (hTRPM4) result in progressive familial heart block. Here, we report the electron cryomicroscopy structure of hTRPM4 in a closed, Na⁺-bound, apo state at pH 7.5 to an overall resolution of 3.7 Å. Five partially hydrated sodium ions are proposed to occupy the center of the conduction pore and the entrance to the coiled-coil domain. We identify an upper gate in the selectivity filter and a lower gate at the entrance to the cytoplasmic coiled-coil domain. Intramolecular interactions exist …

Kruppel-Like Factor 4-Dependent Staufen1-Mediated Mrna Decay Regulates Cortical Neurogenesis, Byoung-San Moon, Jinlun Bai, Mingyang Cai, Chunming Liu, Jiandang Shi, Wange Lu

Molecular and Cellular Biochemistry Faculty Publications

Kruppel-like factor 4 (Klf4) is a zinc-finger-containing protein that plays a critical role in diverse cellular physiology. While most of these functions attribute to its role as a transcription factor, it is postulated that Klf4 may play a role other than transcriptional regulation. Here we demonstrate that Klf4 loss in neural progenitor cells (NPCs) leads to increased neurogenesis and reduced self-renewal in mice. In addition, Klf4 interacts with RNA-binding protein Staufen1 (Stau1) and RNA helicase Ddx5/17. They function together as a complex to maintain NPC self-renewal. We report that Klf4 promotes Stau1 recruitment to the 3′-untranslated region of neurogenesis-associated mRNAs, …

Selective Inhibition Of Ctcf Binding By Ias Directs Tet-Mediated Reprogramming Of 5-Hydroxymethylation Patterns In Ias-Transformed Cells, Matthew Rea, Tyler Gripshover, Yvonne N. Fondufe-Mittendorf

Molecular and Cellular Biochemistry Faculty Publications

Methylation at cytosine (5mC) is a fundamental epigenetic DNA modification recently associated with iAs-mediated carcinogenesis. In contrast, the role of 5-hydroxymethylcytosine (5hmC), the oxidation product of 5mC in iAs-mediated carcinogenesis is unknown. Here we assess the hydroxymethylome in iAs-transformed cells, showing that dynamic modulation of hydroxymethylated DNA is associated with specific transcriptional networks. Moreover, this pathologic iAs-mediated carcinogenesis is characterized by a shift toward a higher hydroxymethylation pattern genome-wide. At specific promoters, hydroxymethylation correlated with increased gene expression. Furthermore, this increase in hydroxymethylation occurs concurrently with an upregulation of ten-eleven translocation (TET) enzymes that oxidize 5-methylcytosine (5mC) in DNA. To …